Support HiDPI displays for wave style underlines

[emacs.git] / src / xterm.c

/* X Communication module for terminals which understand the X protocol.

Copyright (C) 1989, 1993-2017 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */

/* New display code by Gerd Moellmann <gerd@gnu.org>.  */
/* Xt features made by Fred Pierresteguy.  */

#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include "lisp.h"
#include "blockinput.h"

/* This may include sys/types.h, and that somehow loses
   if this is not done before the other system files.  */
#include "xterm.h"
#include <X11/cursorfont.h>

/* If we have Xfixes extension, use it for pointer blanking.  */
#ifdef HAVE_XFIXES
#include <X11/extensions/Xfixes.h>
#endif

/* Using Xft implies that XRender is available.  */
#ifdef HAVE_XFT
#include <X11/extensions/Xrender.h>
#endif

#ifdef HAVE_XDBE
#include <X11/extensions/Xdbe.h>
#endif

/* Load sys/types.h if not already loaded.
   In some systems loading it twice is suicidal.  */
#ifndef makedev
#include <sys/types.h>
#endif /* makedev */

#include <sys/ioctl.h>

#include "systime.h"

#include <fcntl.h>
#include <errno.h>
#include <sys/stat.h>
#include "character.h"
#include "coding.h"
#include "composite.h"
#include "frame.h"
#include "dispextern.h"
#include "xwidget.h"
#include "fontset.h"
#include "termhooks.h"
#include "termopts.h"
#include "termchar.h"
#include "emacs-icon.h"
#include "buffer.h"
#include "window.h"
#include "keyboard.h"
#include "atimer.h"
#include "font.h"
#include "xsettings.h"
#include "sysselect.h"
#include "menu.h"

#ifdef USE_X_TOOLKIT
#include <X11/Shell.h>
#endif

#include <unistd.h>

#ifdef USE_GTK
#include "gtkutil.h"
#ifdef HAVE_GTK3
#include <X11/Xproto.h>
#endif
#endif

#if defined (USE_LUCID) || defined (USE_MOTIF)
#include "../lwlib/xlwmenu.h"
#endif

#ifdef USE_X_TOOLKIT

/* Include toolkit specific headers for the scroll bar widget.  */

#ifdef USE_TOOLKIT_SCROLL_BARS
#if defined USE_MOTIF
#include <Xm/Xm.h>              /* For LESSTIF_VERSION */
#include <Xm/ScrollBar.h>
#else /* !USE_MOTIF i.e. use Xaw */

#ifdef HAVE_XAW3D
#include <X11/Xaw3d/Simple.h>
#include <X11/Xaw3d/Scrollbar.h>
#include <X11/Xaw3d/ThreeD.h>
#else /* !HAVE_XAW3D */
#include <X11/Xaw/Simple.h>
#include <X11/Xaw/Scrollbar.h>
#endif /* !HAVE_XAW3D */
#ifndef XtNpickTop
#define XtNpickTop "pickTop"
#endif /* !XtNpickTop */
#endif /* !USE_MOTIF */
#endif /* USE_TOOLKIT_SCROLL_BARS */

#endif /* USE_X_TOOLKIT */

#ifdef USE_X_TOOLKIT
#include "widget.h"
#ifndef XtNinitialState
#define XtNinitialState "initialState"
#endif
#endif

#include "bitmaps/gray.xbm"

#ifdef HAVE_XKB
#include <X11/XKBlib.h>
#endif

/* Default to using XIM if available.  */
#ifdef USE_XIM
bool use_xim = true;
#else
bool use_xim = false;  /* configure --without-xim */
#endif

/* Non-zero means that a HELP_EVENT has been generated since Emacs
   start.  */

static bool any_help_event_p;

/* This is a chain of structures for all the X displays currently in
   use.  */

struct x_display_info *x_display_list;

#ifdef USE_X_TOOLKIT

/* The application context for Xt use.  */
XtAppContext Xt_app_con;
static String Xt_default_resources[] = {0};

/* Non-zero means user is interacting with a toolkit scroll bar.  */
static bool toolkit_scroll_bar_interaction;

#endif /* USE_X_TOOLKIT */

/* Non-zero timeout value means ignore next mouse click if it arrives
   before that timeout elapses (i.e. as part of the same sequence of
   events resulting from clicking on a frame to select it).  */

static Time ignore_next_mouse_click_timeout;

/* Used locally within XTread_socket.  */

static int x_noop_count;

#ifdef USE_GTK
/* The name of the Emacs icon file.  */
static Lisp_Object xg_default_icon_file;
#endif

/* Some functions take this as char *, not const char *.  */
static char emacs_class[] = EMACS_CLASS;

enum xembed_info
  {
    XEMBED_MAPPED = 1 << 0
  };

enum xembed_message
  {
    XEMBED_EMBEDDED_NOTIFY        = 0,
    XEMBED_WINDOW_ACTIVATE        = 1,
    XEMBED_WINDOW_DEACTIVATE      = 2,
    XEMBED_REQUEST_FOCUS          = 3,
    XEMBED_FOCUS_IN               = 4,
    XEMBED_FOCUS_OUT              = 5,
    XEMBED_FOCUS_NEXT             = 6,
    XEMBED_FOCUS_PREV             = 7,

    XEMBED_MODALITY_ON            = 10,
    XEMBED_MODALITY_OFF           = 11,
    XEMBED_REGISTER_ACCELERATOR   = 12,
    XEMBED_UNREGISTER_ACCELERATOR = 13,
    XEMBED_ACTIVATE_ACCELERATOR   = 14
  };

static void x_free_cr_resources (struct frame *);
static bool x_alloc_nearest_color_1 (Display *, Colormap, XColor *);
static void x_raise_frame (struct frame *);
static void x_lower_frame (struct frame *);
static int x_io_error_quitter (Display *);
static struct terminal *x_create_terminal (struct x_display_info *);
static void x_frame_rehighlight (struct x_display_info *);

static void x_clip_to_row (struct window *, struct glyph_row *,
                           enum glyph_row_area, GC);
static struct scroll_bar *x_window_to_scroll_bar (Display *, Window, int);
static void x_scroll_bar_report_motion (struct frame **, Lisp_Object *,
                                        enum scroll_bar_part *,
                                        Lisp_Object *, Lisp_Object *,
                                        Time *);
static void x_horizontal_scroll_bar_report_motion (struct frame **, Lisp_Object *,
                                                   enum scroll_bar_part *,
                                                   Lisp_Object *, Lisp_Object *,
                                                   Time *);
static bool x_handle_net_wm_state (struct frame *, const XPropertyEvent *);
static void x_check_fullscreen (struct frame *);
static void x_check_expected_move (struct frame *, int, int);
static void x_sync_with_move (struct frame *, int, int, bool);
static int handle_one_xevent (struct x_display_info *,
                              const XEvent *, int *,
                              struct input_event *);
#if ! (defined USE_X_TOOLKIT || defined USE_MOTIF)
static int x_dispatch_event (XEvent *, Display *);
#endif
static void x_wm_set_window_state (struct frame *, int);
static void x_wm_set_icon_pixmap (struct frame *, ptrdiff_t);
static void x_initialize (void);

static bool get_current_wm_state (struct frame *, Window, int *, bool *);

/* Flush display of frame F.  */

static void
x_flush (struct frame *f)
{
  eassert (f && FRAME_X_P (f));
  /* Don't call XFlush when it is not safe to redisplay; the X
     connection may be broken.  */
  if (!NILP (Vinhibit_redisplay))
    return;

  block_input ();
  XFlush (FRAME_X_DISPLAY (f));
  unblock_input ();
}


/* Remove calls to XFlush by defining XFlush to an empty replacement.
   Calls to XFlush should be unnecessary because the X output buffer
   is flushed automatically as needed by calls to XPending,
   XNextEvent, or XWindowEvent according to the XFlush man page.
   XTread_socket calls XPending.  Removing XFlush improves
   performance.  */

#define XFlush(DISPLAY) (void) 0

\f
/***********************************************************************
                              Debugging
 ***********************************************************************/

#if false

/* This is a function useful for recording debugging information about
   the sequence of occurrences in this file.  */

struct record
{
  char *locus;
  int type;
};

struct record event_record[100];

int event_record_index;

void
record_event (char *locus, int type)
{
  if (event_record_index == ARRAYELTS (event_record))
    event_record_index = 0;

  event_record[event_record_index].locus = locus;
  event_record[event_record_index].type = type;
  event_record_index++;
}

#endif

#ifdef USE_CAIRO

#define FRAME_CR_CONTEXT(f)     ((f)->output_data.x->cr_context)
#define FRAME_CR_SURFACE(f)     ((f)->output_data.x->cr_surface)

static struct x_gc_ext_data *
x_gc_get_ext_data (struct frame *f, GC gc, int create_if_not_found_p)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
  XEDataObject object;
  XExtData **head, *ext_data;

  object.gc = gc;
  head = XEHeadOfExtensionList (object);
  ext_data = XFindOnExtensionList (head, dpyinfo->ext_codes->extension);
  if (ext_data == NULL)
    {
      if (!create_if_not_found_p)
        return NULL;
      else
        {
          ext_data = xzalloc (sizeof (*ext_data));
          ext_data->number = dpyinfo->ext_codes->extension;
          ext_data->private_data = xzalloc (sizeof (struct x_gc_ext_data));
          XAddToExtensionList (head, ext_data);
        }
    }
  return (struct x_gc_ext_data *) ext_data->private_data;
}

static void
x_extension_initialize (struct x_display_info *dpyinfo)
{
  XExtCodes *ext_codes = XAddExtension (dpyinfo->display);

  dpyinfo->ext_codes = ext_codes;
}

static void
x_cr_destroy_surface (struct frame *f)
{
  if (FRAME_CR_SURFACE (f))
    {
      cairo_t *cr = FRAME_CR_CONTEXT (f);
      cairo_surface_destroy (FRAME_CR_SURFACE (f));
      FRAME_CR_SURFACE (f) = 0;
      if (cr) cairo_destroy (cr);
      FRAME_CR_CONTEXT (f) = NULL;
    }
}

cairo_t *
x_begin_cr_clip (struct frame *f, GC gc)
{
  cairo_t *cr = FRAME_CR_CONTEXT (f);

  if (!cr)
    {

      if (! FRAME_CR_SURFACE (f))
        {
          cairo_surface_t *surface;
          surface = cairo_xlib_surface_create (FRAME_X_DISPLAY (f),
                                               FRAME_X_DRAWABLE (f),
                                               FRAME_DISPLAY_INFO (f)->visual,
                                               FRAME_PIXEL_WIDTH (f),
                                               FRAME_PIXEL_HEIGHT (f));
          cr = cairo_create (surface);
          cairo_surface_destroy (surface);
        }
      else
        cr = cairo_create (FRAME_CR_SURFACE (f));
      FRAME_CR_CONTEXT (f) = cr;
    }
  cairo_save (cr);

  if (gc)
    {
      struct x_gc_ext_data *gc_ext = x_gc_get_ext_data (f, gc, 0);

      if (gc_ext && gc_ext->n_clip_rects)
        {
          int i;

          for (i = 0; i < gc_ext->n_clip_rects; i++)
            cairo_rectangle (cr, gc_ext->clip_rects[i].x,
                             gc_ext->clip_rects[i].y,
                             gc_ext->clip_rects[i].width,
                             gc_ext->clip_rects[i].height);
          cairo_clip (cr);
        }
    }

  return cr;
}

void
x_end_cr_clip (struct frame *f)
{
  cairo_restore (FRAME_CR_CONTEXT (f));
}

void
x_set_cr_source_with_gc_foreground (struct frame *f, GC gc)
{
  XGCValues xgcv;
  XColor color;

  XGetGCValues (FRAME_X_DISPLAY (f), gc, GCForeground, &xgcv);
  color.pixel = xgcv.foreground;
  x_query_color (f, &color);
  cairo_set_source_rgb (FRAME_CR_CONTEXT (f), color.red / 65535.0,
                        color.green / 65535.0, color.blue / 65535.0);
}

void
x_set_cr_source_with_gc_background (struct frame *f, GC gc)
{
  XGCValues xgcv;
  XColor color;

  XGetGCValues (FRAME_X_DISPLAY (f), gc, GCBackground, &xgcv);
  color.pixel = xgcv.background;
  x_query_color (f, &color);
  cairo_set_source_rgb (FRAME_CR_CONTEXT (f), color.red / 65535.0,
                        color.green / 65535.0, color.blue / 65535.0);
}

/* Fringe bitmaps.  */

static int max_fringe_bmp = 0;
static cairo_pattern_t **fringe_bmp = 0;

static void
x_cr_define_fringe_bitmap (int which, unsigned short *bits, int h, int wd)
{
  int i, stride;
  cairo_surface_t *surface;
  unsigned char *data;
  cairo_pattern_t *pattern;

  if (which >= max_fringe_bmp)
    {
      i = max_fringe_bmp;
      max_fringe_bmp = which + 20;
      fringe_bmp = (cairo_pattern_t **) xrealloc (fringe_bmp, max_fringe_bmp * sizeof (cairo_pattern_t *));
      while (i < max_fringe_bmp)
        fringe_bmp[i++] = 0;
    }

  block_input ();

  surface = cairo_image_surface_create (CAIRO_FORMAT_A1, wd, h);
  stride = cairo_image_surface_get_stride (surface);
  data = cairo_image_surface_get_data (surface);

  for (i = 0; i < h; i++)
    {
      *((unsigned short *) data) = bits[i];
      data += stride;
    }

  cairo_surface_mark_dirty (surface);
  pattern = cairo_pattern_create_for_surface (surface);
  cairo_surface_destroy (surface);

  unblock_input ();

  fringe_bmp[which] = pattern;
}

static void
x_cr_destroy_fringe_bitmap (int which)
{
  if (which >= max_fringe_bmp)
    return;

  if (fringe_bmp[which])
    {
      block_input ();
      cairo_pattern_destroy (fringe_bmp[which]);
      unblock_input ();
    }
  fringe_bmp[which] = 0;
}

static void
x_cr_draw_image (struct frame *f, GC gc, cairo_pattern_t *image,
                 int src_x, int src_y, int width, int height,
                 int dest_x, int dest_y, bool overlay_p)
{
  cairo_t *cr;
  cairo_matrix_t matrix;
  cairo_surface_t *surface;
  cairo_format_t format;

  cr = x_begin_cr_clip (f, gc);
  if (overlay_p)
    cairo_rectangle (cr, dest_x, dest_y, width, height);
  else
    {
      x_set_cr_source_with_gc_background (f, gc);
      cairo_rectangle (cr, dest_x, dest_y, width, height);
      cairo_fill_preserve (cr);
    }
  cairo_clip (cr);
  cairo_matrix_init_translate (&matrix, src_x - dest_x, src_y - dest_y);
  cairo_pattern_set_matrix (image, &matrix);
  cairo_pattern_get_surface (image, &surface);
  format = cairo_image_surface_get_format (surface);
  if (format != CAIRO_FORMAT_A8 && format != CAIRO_FORMAT_A1)
    {
      cairo_set_source (cr, image);
      cairo_fill (cr);
    }
  else
    {
      x_set_cr_source_with_gc_foreground (f, gc);
      cairo_mask (cr, image);
    }
  x_end_cr_clip (f);
}

void
x_cr_draw_frame (cairo_t *cr, struct frame *f)
{
  int width, height;

  width = FRAME_PIXEL_WIDTH (f);
  height = FRAME_PIXEL_HEIGHT (f);

  x_free_cr_resources (f);
  FRAME_CR_CONTEXT (f) = cr;
  x_clear_area (f, 0, 0, width, height);
  expose_frame (f, 0, 0, width, height);
  FRAME_CR_CONTEXT (f) = NULL;
}

static cairo_status_t
x_cr_accumulate_data (void *closure, const unsigned char *data,
                      unsigned int length)
{
  Lisp_Object *acc = (Lisp_Object *) closure;

  *acc = Fcons (make_unibyte_string ((char const *) data, length), *acc);

  return CAIRO_STATUS_SUCCESS;
}

static void
x_cr_destroy (Lisp_Object arg)
{
  cairo_t *cr = (cairo_t *) XSAVE_POINTER (arg, 0);

  block_input ();
  cairo_destroy (cr);
  unblock_input ();
}

Lisp_Object
x_cr_export_frames (Lisp_Object frames, cairo_surface_type_t surface_type)
{
  struct frame *f;
  cairo_surface_t *surface;
  cairo_t *cr;
  int width, height;
  void (*surface_set_size_func) (cairo_surface_t *, double, double) = NULL;
  Lisp_Object acc = Qnil;
  ptrdiff_t count = SPECPDL_INDEX ();

  specbind (Qredisplay_dont_pause, Qt);
  redisplay_preserve_echo_area (31);

  f = XFRAME (XCAR (frames));
  frames = XCDR (frames);
  width = FRAME_PIXEL_WIDTH (f);
  height = FRAME_PIXEL_HEIGHT (f);

  block_input ();
#ifdef CAIRO_HAS_PDF_SURFACE
  if (surface_type == CAIRO_SURFACE_TYPE_PDF)
    {
      surface = cairo_pdf_surface_create_for_stream (x_cr_accumulate_data, &acc,
                                                     width, height);
      surface_set_size_func = cairo_pdf_surface_set_size;
    }
  else
#endif
#ifdef CAIRO_HAS_PNG_FUNCTIONS
  if (surface_type == CAIRO_SURFACE_TYPE_IMAGE)
    surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, width, height);
  else
#endif
#ifdef CAIRO_HAS_PS_SURFACE
  if (surface_type == CAIRO_SURFACE_TYPE_PS)
    {
      surface = cairo_ps_surface_create_for_stream (x_cr_accumulate_data, &acc,
                                                    width, height);
      surface_set_size_func = cairo_ps_surface_set_size;
    }
  else
#endif
#ifdef CAIRO_HAS_SVG_SURFACE
  if (surface_type == CAIRO_SURFACE_TYPE_SVG)
    surface = cairo_svg_surface_create_for_stream (x_cr_accumulate_data, &acc,
                                                   width, height);
  else
#endif
    abort ();

  cr = cairo_create (surface);
  cairo_surface_destroy (surface);
  record_unwind_protect (x_cr_destroy, make_save_ptr (cr));

  while (1)
    {
      x_free_cr_resources (f);
      FRAME_CR_CONTEXT (f) = cr;
      x_clear_area (f, 0, 0, width, height);
      expose_frame (f, 0, 0, width, height);
      FRAME_CR_CONTEXT (f) = NULL;

      if (NILP (frames))
        break;

      cairo_surface_show_page (surface);
      f = XFRAME (XCAR (frames));
      frames = XCDR (frames);
      width = FRAME_PIXEL_WIDTH (f);
      height = FRAME_PIXEL_HEIGHT (f);
      if (surface_set_size_func)
        (*surface_set_size_func) (surface, width, height);

      unblock_input ();
      maybe_quit ();
      block_input ();
    }

#ifdef CAIRO_HAS_PNG_FUNCTIONS
  if (surface_type == CAIRO_SURFACE_TYPE_IMAGE)
    {
      cairo_surface_flush (surface);
      cairo_surface_write_to_png_stream (surface, x_cr_accumulate_data, &acc);
    }
#endif
  unblock_input ();

  unbind_to (count, Qnil);

  return CALLN (Fapply, intern ("concat"), Fnreverse (acc));
}

#endif  /* USE_CAIRO */

static void
x_free_cr_resources (struct frame *f)
{
#ifdef USE_CAIRO
  if (f == NULL)
    {
      Lisp_Object rest, frame;
      FOR_EACH_FRAME (rest, frame)
        if (FRAME_X_P (XFRAME (frame)))
          x_free_cr_resources (XFRAME (frame));
    }
  else
    {
      cairo_t *cr = FRAME_CR_CONTEXT (f);

      if (cr)
        {
          cairo_surface_t *surface = cairo_get_target (cr);

          if (cairo_surface_get_type (surface) == CAIRO_SURFACE_TYPE_XLIB)
            {
              cairo_destroy (cr);
              FRAME_CR_CONTEXT (f) = NULL;
            }
        }
    }
#endif
}

static void
x_set_clip_rectangles (struct frame *f, GC gc, XRectangle *rectangles, int n)
{
  XSetClipRectangles (FRAME_X_DISPLAY (f), gc, 0, 0, rectangles, n, Unsorted);
#ifdef USE_CAIRO
  eassert (n >= 0 && n <= MAX_CLIP_RECTS);

  {
    struct x_gc_ext_data *gc_ext = x_gc_get_ext_data (f, gc, 1);

    gc_ext->n_clip_rects = n;
    memcpy (gc_ext->clip_rects, rectangles, sizeof (XRectangle) * n);
  }
#endif
}

static void
x_reset_clip_rectangles (struct frame *f, GC gc)
{
  XSetClipMask (FRAME_X_DISPLAY (f), gc, None);
#ifdef USE_CAIRO
  {
    struct x_gc_ext_data *gc_ext = x_gc_get_ext_data (f, gc, 0);

    if (gc_ext)
      gc_ext->n_clip_rects = 0;
  }
#endif
}

static void
x_fill_rectangle (struct frame *f, GC gc, int x, int y, int width, int height)
{
#ifdef USE_CAIRO
  cairo_t *cr;

  cr = x_begin_cr_clip (f, gc);
  x_set_cr_source_with_gc_foreground (f, gc);
  cairo_rectangle (cr, x, y, width, height);
  cairo_fill (cr);
  x_end_cr_clip (f);
#else
  XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f),
                  gc, x, y, width, height);
#endif
}

static void
x_draw_rectangle (struct frame *f, GC gc, int x, int y, int width, int height)
{
#ifdef USE_CAIRO
  cairo_t *cr;

  cr = x_begin_cr_clip (f, gc);
  x_set_cr_source_with_gc_foreground (f, gc);
  cairo_rectangle (cr, x + 0.5, y + 0.5, width, height);
  cairo_set_line_width (cr, 1);
  cairo_stroke (cr);
  x_end_cr_clip (f);
#else
  XDrawRectangle (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f),
                  gc, x, y, width, height);
#endif
}

static void
x_clear_window (struct frame *f)
{
#ifdef USE_CAIRO
  cairo_t *cr;

  cr = x_begin_cr_clip (f, NULL);
  x_set_cr_source_with_gc_background (f, f->output_data.x->normal_gc);
  cairo_paint (cr);
  x_end_cr_clip (f);
#else
  if (FRAME_X_DOUBLE_BUFFERED_P (f))
    x_clear_area (f, 0, 0, FRAME_PIXEL_WIDTH (f), FRAME_PIXEL_HEIGHT (f));
  else
    XClearWindow (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f));
#endif
}

#ifdef USE_CAIRO
static void
x_fill_trapezoid_for_relief (struct frame *f, GC gc, int x, int y,
                             int width, int height, int top_p)
{
  cairo_t *cr;

  cr = x_begin_cr_clip (f, gc);
  x_set_cr_source_with_gc_foreground (f, gc);
  cairo_move_to (cr, top_p ? x : x + height, y);
  cairo_line_to (cr, x, y + height);
  cairo_line_to (cr, top_p ? x + width - height : x + width, y + height);
  cairo_line_to (cr, x + width, y);
  cairo_fill (cr);
  x_end_cr_clip (f);
}

enum corners
  {
    CORNER_BOTTOM_RIGHT,        /* 0 -> pi/2 */
    CORNER_BOTTOM_LEFT,         /* pi/2 -> pi */
    CORNER_TOP_LEFT,            /* pi -> 3pi/2 */
    CORNER_TOP_RIGHT,           /* 3pi/2 -> 2pi */
    CORNER_LAST
  };

static void
x_erase_corners_for_relief (struct frame *f, GC gc, int x, int y,
                            int width, int height,
                            double radius, double margin, int corners)
{
  cairo_t *cr;
  int i;

  cr = x_begin_cr_clip (f, gc);
  x_set_cr_source_with_gc_background (f, gc);
  for (i = 0; i < CORNER_LAST; i++)
    if (corners & (1 << i))
      {
        double xm, ym, xc, yc;

        if (i == CORNER_TOP_LEFT || i == CORNER_BOTTOM_LEFT)
          xm = x - margin, xc = xm + radius;
        else
          xm = x + width + margin, xc = xm - radius;
        if (i == CORNER_TOP_LEFT || i == CORNER_TOP_RIGHT)
          ym = y - margin, yc = ym + radius;
        else
          ym = y + height + margin, yc = ym - radius;

        cairo_move_to (cr, xm, ym);
        cairo_arc (cr, xc, yc, radius, i * M_PI_2, (i + 1) * M_PI_2);
      }
  cairo_clip (cr);
  cairo_rectangle (cr, x, y, width, height);
  cairo_fill (cr);
  x_end_cr_clip (f);
}

static void
x_draw_horizontal_wave (struct frame *f, GC gc, int x, int y,
                        int width, int height, int wave_length)
{
  cairo_t *cr;
  double dx = wave_length, dy = height - 1;
  int xoffset, n;

  cr = x_begin_cr_clip (f, gc);
  x_set_cr_source_with_gc_foreground (f, gc);
  cairo_rectangle (cr, x, y, width, height);
  cairo_clip (cr);

  if (x >= 0)
    {
      xoffset = x % (wave_length * 2);
      if (xoffset == 0)
        xoffset = wave_length * 2;
    }
  else
    xoffset = x % (wave_length * 2) + wave_length * 2;
  n = (width + xoffset) / wave_length + 1;
  if (xoffset > wave_length)
    {
      xoffset -= wave_length;
      --n;
      y += height - 1;
      dy = -dy;
    }

  cairo_move_to (cr, x - xoffset + 0.5, y + 0.5);
  while (--n >= 0)
    {
      cairo_rel_line_to (cr, dx, dy);
      dy = -dy;
    }
  cairo_set_line_width (cr, 1);
  cairo_stroke (cr);
  x_end_cr_clip (f);
}
#endif

\f
/* Return the struct x_display_info corresponding to DPY.  */

struct x_display_info *
x_display_info_for_display (Display *dpy)
{
  struct x_display_info *dpyinfo;

  for (dpyinfo = x_display_list; dpyinfo; dpyinfo = dpyinfo->next)
    if (dpyinfo->display == dpy)
      return dpyinfo;

  return 0;
}

static Window
x_find_topmost_parent (struct frame *f)
{
  struct x_output *x = f->output_data.x;
  Window win = None, wi = x->parent_desc;
  Display *dpy = FRAME_X_DISPLAY (f);

  while (wi != FRAME_DISPLAY_INFO (f)->root_window)
    {
      Window root;
      Window *children;
      unsigned int nchildren;

      win = wi;
      if (XQueryTree (dpy, win, &root, &wi, &children, &nchildren))
        XFree (children);
      else
        break;
    }

  return win;
}

#define OPAQUE  0xffffffff

void
x_set_frame_alpha (struct frame *f)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
  Display *dpy = FRAME_X_DISPLAY (f);
  Window win = FRAME_OUTER_WINDOW (f);
  double alpha = 1.0;
  double alpha_min = 1.0;
  unsigned long opac;
  Window parent;

  if (dpyinfo->x_highlight_frame == f)
    alpha = f->alpha[0];
  else
    alpha = f->alpha[1];

  if (FLOATP (Vframe_alpha_lower_limit))
    alpha_min = XFLOAT_DATA (Vframe_alpha_lower_limit);
  else if (INTEGERP (Vframe_alpha_lower_limit))
    alpha_min = (XINT (Vframe_alpha_lower_limit)) / 100.0;

  if (alpha < 0.0)
    return;
  else if (alpha > 1.0)
    alpha = 1.0;
  else if (0.0 <= alpha && alpha < alpha_min && alpha_min <= 1.0)
    alpha = alpha_min;

  opac = alpha * OPAQUE;

  x_catch_errors (dpy);

  /* If there is a parent from the window manager, put the property there
     also, to work around broken window managers that fail to do that.
     Do this unconditionally as this function is called on reparent when
     alpha has not changed on the frame.  */

  if (!FRAME_PARENT_FRAME (f))
    {
      parent = x_find_topmost_parent (f);
      if (parent != None)
        XChangeProperty (dpy, parent, dpyinfo->Xatom_net_wm_window_opacity,
                         XA_CARDINAL, 32, PropModeReplace,
                         (unsigned char *) &opac, 1);
    }

  /* return unless necessary */
  {
    unsigned char *data;
    Atom actual;
    int rc, format;
    unsigned long n, left;

    rc = XGetWindowProperty (dpy, win, dpyinfo->Xatom_net_wm_window_opacity,
                             0, 1, False, XA_CARDINAL,
                             &actual, &format, &n, &left,
                             &data);

    if (rc == Success && actual != None)
      {
        unsigned long value = *(unsigned long *)data;
        XFree (data);
        if (value == opac)
          {
            x_uncatch_errors ();
            return;
          }
      }
  }

  XChangeProperty (dpy, win, dpyinfo->Xatom_net_wm_window_opacity,
                   XA_CARDINAL, 32, PropModeReplace,
                   (unsigned char *) &opac, 1);
  x_uncatch_errors ();
}

/***********************************************************************
                    Starting and ending an update
 ***********************************************************************/

/* Start an update of frame F.  This function is installed as a hook
   for update_begin, i.e. it is called when update_begin is called.
   This function is called prior to calls to x_update_window_begin for
   each window being updated.  Currently, there is nothing to do here
   because all interesting stuff is done on a window basis.  */

static void
x_update_begin (struct frame *f)
{
#ifdef USE_CAIRO
  if (! NILP (tip_frame) && XFRAME (tip_frame) == f
      && ! FRAME_VISIBLE_P (f))
    return;

  if (! FRAME_CR_SURFACE (f))
    {
      int width, height;
#ifdef USE_GTK
      if (FRAME_GTK_WIDGET (f))
        {
          GdkWindow *w = gtk_widget_get_window (FRAME_GTK_WIDGET (f));
          width = gdk_window_get_width (w);
          height = gdk_window_get_height (w);
        }
      else
#endif
        {
          width = FRAME_PIXEL_WIDTH (f);
          height = FRAME_PIXEL_HEIGHT (f);
          if (! FRAME_EXTERNAL_TOOL_BAR (f))
            height += FRAME_TOOL_BAR_HEIGHT (f);
          if (! FRAME_EXTERNAL_MENU_BAR (f))
            height += FRAME_MENU_BAR_HEIGHT (f);
        }

      if (width > 0 && height > 0)
        {
          block_input();
          FRAME_CR_SURFACE (f) = cairo_image_surface_create
            (CAIRO_FORMAT_ARGB32, width, height);
          unblock_input();
        }
    }
#endif /* USE_CAIRO */
}

/* Start update of window W.  */

static void
x_update_window_begin (struct window *w)
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));
  Mouse_HLInfo *hlinfo = MOUSE_HL_INFO (f);

  w->output_cursor = w->cursor;

  block_input ();

  if (f == hlinfo->mouse_face_mouse_frame)
    {
      /* Don't do highlighting for mouse motion during the update.  */
      hlinfo->mouse_face_defer = true;

      /* If F needs to be redrawn, simply forget about any prior mouse
         highlighting.  */
      if (FRAME_GARBAGED_P (f))
        hlinfo->mouse_face_window = Qnil;
    }

  unblock_input ();
}


/* Draw a vertical window border from (x,y0) to (x,y1)  */

static void
x_draw_vertical_window_border (struct window *w, int x, int y0, int y1)
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));
  struct face *face;

  face = FACE_FROM_ID_OR_NULL (f, VERTICAL_BORDER_FACE_ID);
  if (face)
    XSetForeground (FRAME_X_DISPLAY (f), f->output_data.x->normal_gc,
                    face->foreground);

#ifdef USE_CAIRO
  x_fill_rectangle (f, f->output_data.x->normal_gc, x, y0, 1, y1 - y0);
#else
  XDrawLine (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f),
             f->output_data.x->normal_gc, x, y0, x, y1);
#endif
}

/* Draw a window divider from (x0,y0) to (x1,y1)  */

static void
x_draw_window_divider (struct window *w, int x0, int x1, int y0, int y1)
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));
  struct face *face = FACE_FROM_ID_OR_NULL (f, WINDOW_DIVIDER_FACE_ID);
  struct face *face_first
    = FACE_FROM_ID_OR_NULL (f, WINDOW_DIVIDER_FIRST_PIXEL_FACE_ID);
  struct face *face_last
    = FACE_FROM_ID_OR_NULL (f, WINDOW_DIVIDER_LAST_PIXEL_FACE_ID);
  unsigned long color = face ? face->foreground : FRAME_FOREGROUND_PIXEL (f);
  unsigned long color_first = (face_first
                               ? face_first->foreground
                               : FRAME_FOREGROUND_PIXEL (f));
  unsigned long color_last = (face_last
                              ? face_last->foreground
                              : FRAME_FOREGROUND_PIXEL (f));
  Display *display = FRAME_X_DISPLAY (f);

  if (y1 - y0 > x1 - x0 && x1 - x0 > 2)
    /* Vertical.  */
    {
      XSetForeground (display, f->output_data.x->normal_gc, color_first);
      x_fill_rectangle (f, f->output_data.x->normal_gc,
                        x0, y0, 1, y1 - y0);
      XSetForeground (display, f->output_data.x->normal_gc, color);
      x_fill_rectangle (f, f->output_data.x->normal_gc,
                        x0 + 1, y0, x1 - x0 - 2, y1 - y0);
      XSetForeground (display, f->output_data.x->normal_gc, color_last);
      x_fill_rectangle (f, f->output_data.x->normal_gc,
                        x1 - 1, y0, 1, y1 - y0);
    }
  else if (x1 - x0 > y1 - y0 && y1 - y0 > 3)
    /* Horizontal.  */
    {
      XSetForeground (display, f->output_data.x->normal_gc, color_first);
      x_fill_rectangle (f, f->output_data.x->normal_gc,
                        x0, y0, x1 - x0, 1);
      XSetForeground (display, f->output_data.x->normal_gc, color);
      x_fill_rectangle (f, f->output_data.x->normal_gc,
                        x0, y0 + 1, x1 - x0, y1 - y0 - 2);
      XSetForeground (display, f->output_data.x->normal_gc, color_last);
      x_fill_rectangle (f, f->output_data.x->normal_gc,
                        x0, y1 - 1, x1 - x0, 1);
    }
  else
    {
      XSetForeground (display, f->output_data.x->normal_gc, color);
      x_fill_rectangle (f, f->output_data.x->normal_gc,
                        x0, y0, x1 - x0, y1 - y0);
    }
}

/* End update of window W.

   Draw vertical borders between horizontally adjacent windows, and
   display W's cursor if CURSOR_ON_P is non-zero.

   MOUSE_FACE_OVERWRITTEN_P non-zero means that some row containing
   glyphs in mouse-face were overwritten.  In that case we have to
   make sure that the mouse-highlight is properly redrawn.

   W may be a menu bar pseudo-window in case we don't have X toolkit
   support.  Such windows don't have a cursor, so don't display it
   here.  */

static void
x_update_window_end (struct window *w, bool cursor_on_p,
                     bool mouse_face_overwritten_p)
{
  if (!w->pseudo_window_p)
    {
      block_input ();

      if (cursor_on_p)
        display_and_set_cursor (w, true,
                                w->output_cursor.hpos, w->output_cursor.vpos,
                                w->output_cursor.x, w->output_cursor.y);

      if (draw_window_fringes (w, true))
        {
          if (WINDOW_RIGHT_DIVIDER_WIDTH (w))
            x_draw_right_divider (w);
          else
            x_draw_vertical_border (w);
        }

      unblock_input ();
    }

  /* If a row with mouse-face was overwritten, arrange for
     XTframe_up_to_date to redisplay the mouse highlight.  */
  if (mouse_face_overwritten_p)
    {
      Mouse_HLInfo *hlinfo = MOUSE_HL_INFO (XFRAME (w->frame));

      hlinfo->mouse_face_beg_row = hlinfo->mouse_face_beg_col = -1;
      hlinfo->mouse_face_end_row = hlinfo->mouse_face_end_col = -1;
      hlinfo->mouse_face_window = Qnil;
    }
}

/* Show the frame back buffer.  If frame is double-buffered,
   atomically publish to the user's screen graphics updates made since
   the last call to show_back_buffer.  */
static void
show_back_buffer (struct frame *f)
{
  block_input ();
  if (FRAME_X_DOUBLE_BUFFERED_P (f))
    {
#ifdef HAVE_XDBE
      XdbeSwapInfo swap_info;
      memset (&swap_info, 0, sizeof (swap_info));
      swap_info.swap_window = FRAME_X_WINDOW (f);
      swap_info.swap_action = XdbeCopied;
      XdbeSwapBuffers (FRAME_X_DISPLAY (f), &swap_info, 1);
#else
      eassert (!"should have back-buffer only with XDBE");
#endif
    }
  FRAME_X_NEED_BUFFER_FLIP (f) = false;
  unblock_input ();
}

/* Updates back buffer and flushes changes to display.  Called from
   minibuf read code.  Note that we display the back buffer even if
   buffer flipping is blocked.  */
static void
x_flip_and_flush (struct frame *f)
{
  block_input ();
  if (FRAME_X_NEED_BUFFER_FLIP (f))
      show_back_buffer (f);
  x_flush (f);
  unblock_input ();
}

/* End update of frame F.  This function is installed as a hook in
   update_end.  */

static void
x_update_end (struct frame *f)
{
  /* Mouse highlight may be displayed again.  */
  MOUSE_HL_INFO (f)->mouse_face_defer = false;

#ifdef USE_CAIRO
  if (FRAME_CR_SURFACE (f))
    {
      cairo_t *cr = 0;
      block_input();
#if defined (USE_GTK) && defined (HAVE_GTK3)
      if (FRAME_GTK_WIDGET (f))
        {
          GdkWindow *w = gtk_widget_get_window (FRAME_GTK_WIDGET (f));
          cr = gdk_cairo_create (w);
        }
      else
#endif
        {
          cairo_surface_t *surface;
          int width = FRAME_PIXEL_WIDTH (f);
          int height = FRAME_PIXEL_HEIGHT (f);
          if (! FRAME_EXTERNAL_TOOL_BAR (f))
            height += FRAME_TOOL_BAR_HEIGHT (f);
          if (! FRAME_EXTERNAL_MENU_BAR (f))
            height += FRAME_MENU_BAR_HEIGHT (f);
          surface = cairo_xlib_surface_create (FRAME_X_DISPLAY (f),
                                               FRAME_X_DRAWABLE (f),
                                               FRAME_DISPLAY_INFO (f)->visual,
                                               width,
                                               height);
          cr = cairo_create (surface);
          cairo_surface_destroy (surface);
        }

      cairo_set_source_surface (cr, FRAME_CR_SURFACE (f), 0, 0);
      cairo_paint (cr);
      cairo_destroy (cr);
      unblock_input ();
    }
#endif

#ifndef XFlush
  block_input ();
  XFlush (FRAME_X_DISPLAY (f));
  unblock_input ();
#endif
}

/* This function is called from various places in xdisp.c
   whenever a complete update has been performed.  */

static void
XTframe_up_to_date (struct frame *f)
{
  eassert (FRAME_X_P (f));
  block_input ();
  FRAME_MOUSE_UPDATE (f);
  if (!buffer_flipping_blocked_p () && FRAME_X_NEED_BUFFER_FLIP (f))
    show_back_buffer (f);
  unblock_input ();
}

static void
XTbuffer_flipping_unblocked_hook (struct frame *f)
{
  if (FRAME_X_NEED_BUFFER_FLIP (f))
    show_back_buffer (f);
}

/**
 * x_clear_under_internal_border:
 *
 * Clear area of frame F's internal border.  If the internal border face
 * of F has been specified (is not null), fill the area with that face.
 */
void
x_clear_under_internal_border (struct frame *f)
{
  if (FRAME_INTERNAL_BORDER_WIDTH (f) > 0)
    {
      int border = FRAME_INTERNAL_BORDER_WIDTH (f);
      int width = FRAME_PIXEL_WIDTH (f);
      int height = FRAME_PIXEL_HEIGHT (f);
#ifdef USE_GTK
      int margin = 0;
#else
      int margin = FRAME_TOP_MARGIN_HEIGHT (f);
#endif
      struct face *face = FACE_FROM_ID_OR_NULL (f, INTERNAL_BORDER_FACE_ID);

      block_input ();

      if (face)
        {
          unsigned long color = face->background;
          Display *display = FRAME_X_DISPLAY (f);
          GC gc = f->output_data.x->normal_gc;

          XSetForeground (display, gc, color);
          x_fill_rectangle (f, gc, 0, margin, width, border);
          x_fill_rectangle (f, gc, 0, 0, border, height);
          x_fill_rectangle (f, gc, width - border, 0, border, height);
          x_fill_rectangle (f, gc, 0, height - border, width, border);
          XSetForeground (display, gc, FRAME_FOREGROUND_PIXEL (f));
        }
      else
        {
          x_clear_area (f, 0, 0, border, height);
          x_clear_area (f, 0, margin, width, border);
          x_clear_area (f, width - border, 0, border, height);
          x_clear_area (f, 0, height - border, width, border);
        }

      unblock_input ();
    }
}

/* Draw truncation mark bitmaps, continuation mark bitmaps, overlay
   arrow bitmaps, or clear the fringes if no bitmaps are required
   before DESIRED_ROW is made current.  This function is called from
   update_window_line only if it is known that there are differences
   between bitmaps to be drawn between current row and DESIRED_ROW.  */

static void
x_after_update_window_line (struct window *w, struct glyph_row *desired_row)
{
  eassert (w);

  if (!desired_row->mode_line_p && !w->pseudo_window_p)
    desired_row->redraw_fringe_bitmaps_p = true;

#ifdef USE_X_TOOLKIT
  /* When a window has disappeared, make sure that no rest of
     full-width rows stays visible in the internal border.  Could
     check here if updated window is the leftmost/rightmost window,
     but I guess it's not worth doing since vertically split windows
     are almost never used, internal border is rarely set, and the
     overhead is very small.  */
  {
    struct frame *f;
    int width, height;

    if (windows_or_buffers_changed
        && desired_row->full_width_p
        && (f = XFRAME (w->frame),
            width = FRAME_INTERNAL_BORDER_WIDTH (f),
            width != 0)
        && (height = desired_row->visible_height,
            height > 0))
      {
        int y = WINDOW_TO_FRAME_PIXEL_Y (w, max (0, desired_row->y));
        struct face *face = FACE_FROM_ID_OR_NULL (f, INTERNAL_BORDER_FACE_ID);

        block_input ();
        if (face)
          {
            unsigned long color = face->background;
            Display *display = FRAME_X_DISPLAY (f);

            XSetForeground (display, f->output_data.x->normal_gc, color);
            x_fill_rectangle (f, f->output_data.x->normal_gc,
                              0, y, width, height);
            x_fill_rectangle (f, f->output_data.x->normal_gc,
                              FRAME_PIXEL_WIDTH (f) - width, y, width, height);
          }
        else
          {
            x_clear_area (f, 0, y, width, height);
            x_clear_area (f, FRAME_PIXEL_WIDTH (f) - width, y, width, height);
          }
        unblock_input ();
      }
  }
#endif
}

static void
x_draw_fringe_bitmap (struct window *w, struct glyph_row *row, struct draw_fringe_bitmap_params *p)
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));
  Display *display = FRAME_X_DISPLAY (f);
  GC gc = f->output_data.x->normal_gc;
  struct face *face = p->face;

  /* Must clip because of partially visible lines.  */
  x_clip_to_row (w, row, ANY_AREA, gc);

  if (p->bx >= 0 && !p->overlay_p)
    {
      /* In case the same realized face is used for fringes and
         for something displayed in the text (e.g. face `region' on
         mono-displays, the fill style may have been changed to
         FillSolid in x_draw_glyph_string_background.  */
      if (face->stipple)
        XSetFillStyle (display, face->gc, FillOpaqueStippled);
      else
        XSetForeground (display, face->gc, face->background);

      x_fill_rectangle (f, face->gc, p->bx, p->by, p->nx, p->ny);

      if (!face->stipple)
        XSetForeground (display, face->gc, face->foreground);
    }

#ifdef USE_CAIRO
  if (p->which && p->which < max_fringe_bmp)
    {
      XGCValues gcv;

      XGetGCValues (display, gc, GCForeground | GCBackground, &gcv);
      XSetForeground (display, gc, (p->cursor_p
                                    ? (p->overlay_p ? face->background
                                       : f->output_data.x->cursor_pixel)
                                    : face->foreground));
      XSetBackground (display, gc, face->background);
      x_cr_draw_image (f, gc, fringe_bmp[p->which], 0, p->dh,
                       p->wd, p->h, p->x, p->y, p->overlay_p);
      XSetForeground (display, gc, gcv.foreground);
      XSetBackground (display, gc, gcv.background);
    }
#else  /* not USE_CAIRO */
  if (p->which)
    {
      Drawable drawable = FRAME_X_DRAWABLE (f);
      char *bits;
      Pixmap pixmap, clipmask = (Pixmap) 0;
      int depth = DefaultDepthOfScreen (FRAME_X_SCREEN (f));
      XGCValues gcv;

      if (p->wd > 8)
        bits = (char *) (p->bits + p->dh);
      else
        bits = (char *) p->bits + p->dh;

      /* Draw the bitmap.  I believe these small pixmaps can be cached
         by the server.  */
      pixmap = XCreatePixmapFromBitmapData (display, drawable, bits, p->wd, p->h,
                                            (p->cursor_p
                                             ? (p->overlay_p ? face->background
                                                : f->output_data.x->cursor_pixel)
                                             : face->foreground),
                                            face->background, depth);

      if (p->overlay_p)
        {
          clipmask = XCreatePixmapFromBitmapData (display,
                                                  FRAME_DISPLAY_INFO (f)->root_window,
                                                  bits, p->wd, p->h,
                                                  1, 0, 1);
          gcv.clip_mask = clipmask;
          gcv.clip_x_origin = p->x;
          gcv.clip_y_origin = p->y;
          XChangeGC (display, gc, GCClipMask | GCClipXOrigin | GCClipYOrigin, &gcv);
        }

      XCopyArea (display, pixmap, drawable, gc, 0, 0,
                 p->wd, p->h, p->x, p->y);
      XFreePixmap (display, pixmap);

      if (p->overlay_p)
        {
          gcv.clip_mask = (Pixmap) 0;
          XChangeGC (display, gc, GCClipMask, &gcv);
          XFreePixmap (display, clipmask);
        }
    }
#endif  /* not USE_CAIRO */

  x_reset_clip_rectangles (f, gc);
}

/***********************************************************************
                            Glyph display
 ***********************************************************************/



static void x_set_glyph_string_clipping (struct glyph_string *);
static void x_set_glyph_string_gc (struct glyph_string *);
static void x_draw_glyph_string_foreground (struct glyph_string *);
static void x_draw_composite_glyph_string_foreground (struct glyph_string *);
static void x_draw_glyph_string_box (struct glyph_string *);
static void x_draw_glyph_string  (struct glyph_string *);
static _Noreturn void x_delete_glyphs (struct frame *, int);
static void x_compute_glyph_string_overhangs (struct glyph_string *);
static void x_set_cursor_gc (struct glyph_string *);
static void x_set_mode_line_face_gc (struct glyph_string *);
static void x_set_mouse_face_gc (struct glyph_string *);
static bool x_alloc_lighter_color (struct frame *, Display *, Colormap,
                                   unsigned long *, double, int);
static void x_setup_relief_color (struct frame *, struct relief *,
                                  double, int, unsigned long);
static void x_setup_relief_colors (struct glyph_string *);
static void x_draw_image_glyph_string (struct glyph_string *);
static void x_draw_image_relief (struct glyph_string *);
static void x_draw_image_foreground (struct glyph_string *);
static void x_draw_image_foreground_1 (struct glyph_string *, Pixmap);
static void x_clear_glyph_string_rect (struct glyph_string *, int,
                                       int, int, int);
static void x_draw_relief_rect (struct frame *, int, int, int, int,
                                int, bool, bool, bool, bool, bool,
                                XRectangle *);
static void x_draw_box_rect (struct glyph_string *, int, int, int, int,
                             int, bool, bool, XRectangle *);
static void x_scroll_bar_clear (struct frame *);

#ifdef GLYPH_DEBUG
static void x_check_font (struct frame *, struct font *);
#endif


/* Set S->gc to a suitable GC for drawing glyph string S in cursor
   face.  */

static void
x_set_cursor_gc (struct glyph_string *s)
{
  if (s->font == FRAME_FONT (s->f)
      && s->face->background == FRAME_BACKGROUND_PIXEL (s->f)
      && s->face->foreground == FRAME_FOREGROUND_PIXEL (s->f)
      && !s->cmp)
    s->gc = s->f->output_data.x->cursor_gc;
  else
    {
      /* Cursor on non-default face: must merge.  */
      XGCValues xgcv;
      unsigned long mask;

      xgcv.background = s->f->output_data.x->cursor_pixel;
      xgcv.foreground = s->face->background;

      /* If the glyph would be invisible, try a different foreground.  */
      if (xgcv.foreground == xgcv.background)
        xgcv.foreground = s->face->foreground;
      if (xgcv.foreground == xgcv.background)
        xgcv.foreground = s->f->output_data.x->cursor_foreground_pixel;
      if (xgcv.foreground == xgcv.background)
        xgcv.foreground = s->face->foreground;

      /* Make sure the cursor is distinct from text in this face.  */
      if (xgcv.background == s->face->background
          && xgcv.foreground == s->face->foreground)
        {
          xgcv.background = s->face->foreground;
          xgcv.foreground = s->face->background;
        }

      IF_DEBUG (x_check_font (s->f, s->font));
      xgcv.graphics_exposures = False;
      mask = GCForeground | GCBackground | GCGraphicsExposures;

      if (FRAME_DISPLAY_INFO (s->f)->scratch_cursor_gc)
        XChangeGC (s->display, FRAME_DISPLAY_INFO (s->f)->scratch_cursor_gc,
                   mask, &xgcv);
      else
        FRAME_DISPLAY_INFO (s->f)->scratch_cursor_gc
          = XCreateGC (s->display, FRAME_X_DRAWABLE (s->f), mask, &xgcv);

      s->gc = FRAME_DISPLAY_INFO (s->f)->scratch_cursor_gc;
    }
}


/* Set up S->gc of glyph string S for drawing text in mouse face.  */

static void
x_set_mouse_face_gc (struct glyph_string *s)
{
  int face_id;
  struct face *face;

  /* What face has to be used last for the mouse face?  */
  face_id = MOUSE_HL_INFO (s->f)->mouse_face_face_id;
  face = FACE_FROM_ID_OR_NULL (s->f, face_id);
  if (face == NULL)
    face = FACE_FROM_ID (s->f, MOUSE_FACE_ID);

  if (s->first_glyph->type == CHAR_GLYPH)
    face_id = FACE_FOR_CHAR (s->f, face, s->first_glyph->u.ch, -1, Qnil);
  else
    face_id = FACE_FOR_CHAR (s->f, face, 0, -1, Qnil);
  s->face = FACE_FROM_ID (s->f, face_id);
  prepare_face_for_display (s->f, s->face);

  if (s->font == s->face->font)
    s->gc = s->face->gc;
  else
    {
      /* Otherwise construct scratch_cursor_gc with values from FACE
         except for FONT.  */
      XGCValues xgcv;
      unsigned long mask;

      xgcv.background = s->face->background;
      xgcv.foreground = s->face->foreground;
      xgcv.graphics_exposures = False;
      mask = GCForeground | GCBackground | GCGraphicsExposures;

      if (FRAME_DISPLAY_INFO (s->f)->scratch_cursor_gc)
        XChangeGC (s->display, FRAME_DISPLAY_INFO (s->f)->scratch_cursor_gc,
                   mask, &xgcv);
      else
        FRAME_DISPLAY_INFO (s->f)->scratch_cursor_gc
          = XCreateGC (s->display, FRAME_X_DRAWABLE (s->f), mask, &xgcv);

      s->gc = FRAME_DISPLAY_INFO (s->f)->scratch_cursor_gc;

    }
  eassert (s->gc != 0);
}


/* Set S->gc of glyph string S to a GC suitable for drawing a mode line.
   Faces to use in the mode line have already been computed when the
   matrix was built, so there isn't much to do, here.  */

static void
x_set_mode_line_face_gc (struct glyph_string *s)
{
  s->gc = s->face->gc;
}


/* Set S->gc of glyph string S for drawing that glyph string.  Set
   S->stippled_p to a non-zero value if the face of S has a stipple
   pattern.  */

static void
x_set_glyph_string_gc (struct glyph_string *s)
{
  prepare_face_for_display (s->f, s->face);

  if (s->hl == DRAW_NORMAL_TEXT)
    {
      s->gc = s->face->gc;
      s->stippled_p = s->face->stipple != 0;
    }
  else if (s->hl == DRAW_INVERSE_VIDEO)
    {
      x_set_mode_line_face_gc (s);
      s->stippled_p = s->face->stipple != 0;
    }
  else if (s->hl == DRAW_CURSOR)
    {
      x_set_cursor_gc (s);
      s->stippled_p = false;
    }
  else if (s->hl == DRAW_MOUSE_FACE)
    {
      x_set_mouse_face_gc (s);
      s->stippled_p = s->face->stipple != 0;
    }
  else if (s->hl == DRAW_IMAGE_RAISED
           || s->hl == DRAW_IMAGE_SUNKEN)
    {
      s->gc = s->face->gc;
      s->stippled_p = s->face->stipple != 0;
    }
  else
    emacs_abort ();

  /* GC must have been set.  */
  eassert (s->gc != 0);
}


/* Set clipping for output of glyph string S.  S may be part of a mode
   line or menu if we don't have X toolkit support.  */

static void
x_set_glyph_string_clipping (struct glyph_string *s)
{
  XRectangle *r = s->clip;
  int n = get_glyph_string_clip_rects (s, r, 2);

  if (n > 0)
    x_set_clip_rectangles (s->f, s->gc, r, n);
  s->num_clips = n;
}


/* Set SRC's clipping for output of glyph string DST.  This is called
   when we are drawing DST's left_overhang or right_overhang only in
   the area of SRC.  */

static void
x_set_glyph_string_clipping_exactly (struct glyph_string *src, struct glyph_string *dst)
{
  XRectangle r;

  r.x = src->x;
  r.width = src->width;
  r.y = src->y;
  r.height = src->height;
  dst->clip[0] = r;
  dst->num_clips = 1;
  x_set_clip_rectangles (dst->f, dst->gc, &r, 1);
}


/* RIF:
   Compute left and right overhang of glyph string S.  */

static void
x_compute_glyph_string_overhangs (struct glyph_string *s)
{
  if (s->cmp == NULL
      && (s->first_glyph->type == CHAR_GLYPH
          || s->first_glyph->type == COMPOSITE_GLYPH))
    {
      struct font_metrics metrics;

      if (s->first_glyph->type == CHAR_GLYPH)
        {
          unsigned *code = alloca (sizeof (unsigned) * s->nchars);
          struct font *font = s->font;
          int i;

          for (i = 0; i < s->nchars; i++)
            code[i] = (s->char2b[i].byte1 << 8) | s->char2b[i].byte2;
          font->driver->text_extents (font, code, s->nchars, &metrics);
        }
      else
        {
          Lisp_Object gstring = composition_gstring_from_id (s->cmp_id);

          composition_gstring_width (gstring, s->cmp_from, s->cmp_to, &metrics);
        }
      s->right_overhang = (metrics.rbearing > metrics.width
                           ? metrics.rbearing - metrics.width : 0);
      s->left_overhang = metrics.lbearing < 0 ? - metrics.lbearing : 0;
    }
  else if (s->cmp)
    {
      s->right_overhang = s->cmp->rbearing - s->cmp->pixel_width;
      s->left_overhang = - s->cmp->lbearing;
    }
}


/* Fill rectangle X, Y, W, H with background color of glyph string S.  */

static void
x_clear_glyph_string_rect (struct glyph_string *s, int x, int y, int w, int h)
{
  XGCValues xgcv;
  XGetGCValues (s->display, s->gc, GCForeground | GCBackground, &xgcv);
  XSetForeground (s->display, s->gc, xgcv.background);
  x_fill_rectangle (s->f, s->gc, x, y, w, h);
  XSetForeground (s->display, s->gc, xgcv.foreground);
}


/* Draw the background of glyph_string S.  If S->background_filled_p
   is non-zero don't draw it.  FORCE_P non-zero means draw the
   background even if it wouldn't be drawn normally.  This is used
   when a string preceding S draws into the background of S, or S
   contains the first component of a composition.  */

static void
x_draw_glyph_string_background (struct glyph_string *s, bool force_p)
{
  /* Nothing to do if background has already been drawn or if it
     shouldn't be drawn in the first place.  */
  if (!s->background_filled_p)
    {
      int box_line_width = max (s->face->box_line_width, 0);

      if (s->stippled_p)
        {
          /* Fill background with a stipple pattern.  */
          XSetFillStyle (s->display, s->gc, FillOpaqueStippled);
          x_fill_rectangle (s->f, s->gc, s->x,
                          s->y + box_line_width,
                          s->background_width,
                          s->height - 2 * box_line_width);
          XSetFillStyle (s->display, s->gc, FillSolid);
          s->background_filled_p = true;
        }
      else if (FONT_HEIGHT (s->font) < s->height - 2 * box_line_width
               /* When xdisp.c ignores FONT_HEIGHT, we cannot trust
                  font dimensions, since the actual glyphs might be
                  much smaller.  So in that case we always clear the
                  rectangle with background color.  */
               || FONT_TOO_HIGH (s->font)
               || s->font_not_found_p
               || s->extends_to_end_of_line_p
               || force_p)
        {
          x_clear_glyph_string_rect (s, s->x, s->y + box_line_width,
                                     s->background_width,
                                     s->height - 2 * box_line_width);
          s->background_filled_p = true;
        }
    }
}


/* Draw the foreground of glyph string S.  */

static void
x_draw_glyph_string_foreground (struct glyph_string *s)
{
  int i, x;

  /* If first glyph of S has a left box line, start drawing the text
     of S to the right of that box line.  */
  if (s->face->box != FACE_NO_BOX
      && s->first_glyph->left_box_line_p)
    x = s->x + eabs (s->face->box_line_width);
  else
    x = s->x;

  /* Draw characters of S as rectangles if S's font could not be
     loaded.  */
  if (s->font_not_found_p)
    {
      for (i = 0; i < s->nchars; ++i)
        {
          struct glyph *g = s->first_glyph + i;
          x_draw_rectangle (s->f,
                          s->gc, x, s->y, g->pixel_width - 1,
                          s->height - 1);
          x += g->pixel_width;
        }
    }
  else
    {
      struct font *font = s->font;
      int boff = font->baseline_offset;
      int y;

      if (font->vertical_centering)
        boff = VCENTER_BASELINE_OFFSET (font, s->f) - boff;

      y = s->ybase - boff;
      if (s->for_overlaps
          || (s->background_filled_p && s->hl != DRAW_CURSOR))
        font->driver->draw (s, 0, s->nchars, x, y, false);
      else
        font->driver->draw (s, 0, s->nchars, x, y, true);
      if (s->face->overstrike)
        font->driver->draw (s, 0, s->nchars, x + 1, y, false);
    }
}

/* Draw the foreground of composite glyph string S.  */

static void
x_draw_composite_glyph_string_foreground (struct glyph_string *s)
{
  int i, j, x;
  struct font *font = s->font;

  /* If first glyph of S has a left box line, start drawing the text
     of S to the right of that box line.  */
  if (s->face && s->face->box != FACE_NO_BOX
      && s->first_glyph->left_box_line_p)
    x = s->x + eabs (s->face->box_line_width);
  else
    x = s->x;

  /* S is a glyph string for a composition.  S->cmp_from is the index
     of the first character drawn for glyphs of this composition.
     S->cmp_from == 0 means we are drawing the very first character of
     this composition.  */

  /* Draw a rectangle for the composition if the font for the very
     first character of the composition could not be loaded.  */
  if (s->font_not_found_p)
    {
      if (s->cmp_from == 0)
        x_draw_rectangle (s->f, s->gc, x, s->y,
                        s->width - 1, s->height - 1);
    }
  else if (! s->first_glyph->u.cmp.automatic)
    {
      int y = s->ybase;

      for (i = 0, j = s->cmp_from; i < s->nchars; i++, j++)
        /* TAB in a composition means display glyphs with padding
           space on the left or right.  */
        if (COMPOSITION_GLYPH (s->cmp, j) != '\t')
          {
            int xx = x + s->cmp->offsets[j * 2];
            int yy = y - s->cmp->offsets[j * 2 + 1];

            font->driver->draw (s, j, j + 1, xx, yy, false);
            if (s->face->overstrike)
              font->driver->draw (s, j, j + 1, xx + 1, yy, false);
          }
    }
  else
    {
      Lisp_Object gstring = composition_gstring_from_id (s->cmp_id);
      Lisp_Object glyph;
      int y = s->ybase;
      int width = 0;

      for (i = j = s->cmp_from; i < s->cmp_to; i++)
        {
          glyph = LGSTRING_GLYPH (gstring, i);
          if (NILP (LGLYPH_ADJUSTMENT (glyph)))
            width += LGLYPH_WIDTH (glyph);
          else
            {
              int xoff, yoff, wadjust;

              if (j < i)
                {
                  font->driver->draw (s, j, i, x, y, false);
                  if (s->face->overstrike)
                    font->driver->draw (s, j, i, x + 1, y, false);
                  x += width;
                }
              xoff = LGLYPH_XOFF (glyph);
              yoff = LGLYPH_YOFF (glyph);
              wadjust = LGLYPH_WADJUST (glyph);
              font->driver->draw (s, i, i + 1, x + xoff, y + yoff, false);
              if (s->face->overstrike)
                font->driver->draw (s, i, i + 1, x + xoff + 1, y + yoff,
                                    false);
              x += wadjust;
              j = i + 1;
              width = 0;
            }
        }
      if (j < i)
        {
          font->driver->draw (s, j, i, x, y, false);
          if (s->face->overstrike)
            font->driver->draw (s, j, i, x + 1, y, false);
        }
    }
}


/* Draw the foreground of glyph string S for glyphless characters.  */

static void
x_draw_glyphless_glyph_string_foreground (struct glyph_string *s)
{
  struct glyph *glyph = s->first_glyph;
  XChar2b char2b[8];
  int x, i, j;

  /* If first glyph of S has a left box line, start drawing the text
     of S to the right of that box line.  */
  if (s->face && s->face->box != FACE_NO_BOX
      && s->first_glyph->left_box_line_p)
    x = s->x + eabs (s->face->box_line_width);
  else
    x = s->x;

  s->char2b = char2b;

  for (i = 0; i < s->nchars; i++, glyph++)
    {
      char buf[7], *str = NULL;
      int len = glyph->u.glyphless.len;

      if (glyph->u.glyphless.method == GLYPHLESS_DISPLAY_ACRONYM)
        {
          if (len > 0
              && CHAR_TABLE_P (Vglyphless_char_display)
              && (CHAR_TABLE_EXTRA_SLOTS (XCHAR_TABLE (Vglyphless_char_display))
                  >= 1))
            {
              Lisp_Object acronym
                = (! glyph->u.glyphless.for_no_font
                   ? CHAR_TABLE_REF (Vglyphless_char_display,
                                     glyph->u.glyphless.ch)
                   : XCHAR_TABLE (Vglyphless_char_display)->extras[0]);
              if (STRINGP (acronym))
                str = SSDATA (acronym);
            }
        }
      else if (glyph->u.glyphless.method == GLYPHLESS_DISPLAY_HEX_CODE)
        {
          unsigned int ch = glyph->u.glyphless.ch;
          eassume (ch <= MAX_CHAR);
          sprintf (buf, "%0*X", ch < 0x10000 ? 4 : 6, ch);
          str = buf;
        }

      if (str)
        {
          int upper_len = (len + 1) / 2;
          unsigned code;

          /* It is assured that all LEN characters in STR is ASCII.  */
          for (j = 0; j < len; j++)
            {
              code = s->font->driver->encode_char (s->font, str[j]);
              STORE_XCHAR2B (char2b + j, code >> 8, code & 0xFF);
            }
          s->font->driver->draw (s, 0, upper_len,
                                 x + glyph->slice.glyphless.upper_xoff,
                                 s->ybase + glyph->slice.glyphless.upper_yoff,
                                 false);
          s->font->driver->draw (s, upper_len, len,
                                 x + glyph->slice.glyphless.lower_xoff,
                                 s->ybase + glyph->slice.glyphless.lower_yoff,
                                 false);
        }
      if (glyph->u.glyphless.method != GLYPHLESS_DISPLAY_THIN_SPACE)
        x_draw_rectangle (s->f, s->gc,
                        x, s->ybase - glyph->ascent,
                        glyph->pixel_width - 1,
                        glyph->ascent + glyph->descent - 1);
      x += glyph->pixel_width;
   }
}

#ifdef USE_X_TOOLKIT

#ifdef USE_LUCID

/* Return the frame on which widget WIDGET is used.. Abort if frame
   cannot be determined.  */

static struct frame *
x_frame_of_widget (Widget widget)
{
  struct x_display_info *dpyinfo;
  Lisp_Object tail, frame;
  struct frame *f;

  dpyinfo = x_display_info_for_display (XtDisplay (widget));

  /* Find the top-level shell of the widget.  Note that this function
     can be called when the widget is not yet realized, so XtWindow
     (widget) == 0.  That's the reason we can't simply use
     x_any_window_to_frame.  */
  while (!XtIsTopLevelShell (widget))
    widget = XtParent (widget);

  /* Look for a frame with that top-level widget.  Allocate the color
     on that frame to get the right gamma correction value.  */
  FOR_EACH_FRAME (tail, frame)
    {
      f = XFRAME (frame);
      if (FRAME_X_P (f)
          && f->output_data.nothing != 1
          && FRAME_DISPLAY_INFO (f) == dpyinfo
          && f->output_data.x->widget == widget)
        return f;
    }
  emacs_abort ();
}

/* Allocate a color which is lighter or darker than *PIXEL by FACTOR
   or DELTA.  Try a color with RGB values multiplied by FACTOR first.
   If this produces the same color as PIXEL, try a color where all RGB
   values have DELTA added.  Return the allocated color in *PIXEL.
   DISPLAY is the X display, CMAP is the colormap to operate on.
   Value is true if successful.  */

bool
x_alloc_lighter_color_for_widget (Widget widget, Display *display, Colormap cmap,
                                  unsigned long *pixel, double factor, int delta)
{
  struct frame *f = x_frame_of_widget (widget);
  return x_alloc_lighter_color (f, display, cmap, pixel, factor, delta);
}

#endif /* USE_LUCID */


/* Structure specifying which arguments should be passed by Xt to
   cvt_string_to_pixel.  We want the widget's screen and colormap.  */

static XtConvertArgRec cvt_string_to_pixel_args[] =
  {
    {XtWidgetBaseOffset, (XtPointer) offsetof (WidgetRec, core.screen),
     sizeof (Screen *)},
    {XtWidgetBaseOffset, (XtPointer) offsetof (WidgetRec, core.colormap),
     sizeof (Colormap)}
  };


/* The address of this variable is returned by
   cvt_string_to_pixel.  */

static Pixel cvt_string_to_pixel_value;


/* Convert a color name to a pixel color.

   DPY is the display we are working on.

   ARGS is an array of *NARGS XrmValue structures holding additional
   information about the widget for which the conversion takes place.
   The contents of this array are determined by the specification
   in cvt_string_to_pixel_args.

   FROM is a pointer to an XrmValue which points to the color name to
   convert.  TO is an XrmValue in which to return the pixel color.

   CLOSURE_RET is a pointer to user-data, in which we record if
   we allocated the color or not.

   Value is True if successful, False otherwise.  */

static Boolean
cvt_string_to_pixel (Display *dpy, XrmValue *args, Cardinal *nargs,
                     XrmValue *from, XrmValue *to,
                     XtPointer *closure_ret)
{
  Screen *screen;
  Colormap cmap;
  Pixel pixel;
  String color_name;
  XColor color;

  if (*nargs != 2)
    {
      XtAppWarningMsg (XtDisplayToApplicationContext (dpy),
                       "wrongParameters", "cvt_string_to_pixel",
                       "XtToolkitError",
                       "Screen and colormap args required", NULL, NULL);
      return False;
    }

  screen = *(Screen **) args[0].addr;
  cmap = *(Colormap *) args[1].addr;
  color_name = (String) from->addr;

  if (strcmp (color_name, XtDefaultBackground) == 0)
    {
      *closure_ret = (XtPointer) False;
      pixel = WhitePixelOfScreen (screen);
    }
  else if (strcmp (color_name, XtDefaultForeground) == 0)
    {
      *closure_ret = (XtPointer) False;
      pixel = BlackPixelOfScreen (screen);
    }
  else if (XParseColor (dpy, cmap, color_name, &color)
           && x_alloc_nearest_color_1 (dpy, cmap, &color))
    {
      pixel = color.pixel;
      *closure_ret = (XtPointer) True;
    }
  else
    {
      String params[1];
      Cardinal nparams = 1;

      params[0] = color_name;
      XtAppWarningMsg (XtDisplayToApplicationContext (dpy),
                       "badValue", "cvt_string_to_pixel",
                       "XtToolkitError", "Invalid color '%s'",
                       params, &nparams);
      return False;
    }

  if (to->addr != NULL)
    {
      if (to->size < sizeof (Pixel))
        {
          to->size = sizeof (Pixel);
          return False;
        }

      *(Pixel *) to->addr = pixel;
    }
  else
    {
      cvt_string_to_pixel_value = pixel;
      to->addr = (XtPointer) &cvt_string_to_pixel_value;
    }

  to->size = sizeof (Pixel);
  return True;
}


/* Free a pixel color which was previously allocated via
   cvt_string_to_pixel.  This is registered as the destructor
   for this type of resource via XtSetTypeConverter.

   APP is the application context in which we work.

   TO is a pointer to an XrmValue holding the color to free.
   CLOSURE is the value we stored in CLOSURE_RET for this color
   in cvt_string_to_pixel.

   ARGS and NARGS are like for cvt_string_to_pixel.  */

static void
cvt_pixel_dtor (XtAppContext app, XrmValuePtr to, XtPointer closure, XrmValuePtr args,
                Cardinal *nargs)
{
  if (*nargs != 2)
    {
      XtAppWarningMsg (app, "wrongParameters", "cvt_pixel_dtor",
                       "XtToolkitError",
                       "Screen and colormap arguments required",
                       NULL, NULL);
    }
  else if (closure != NULL)
    {
      /* We did allocate the pixel, so free it.  */
      Screen *screen = *(Screen **) args[0].addr;
      Colormap cmap = *(Colormap *) args[1].addr;
      x_free_dpy_colors (DisplayOfScreen (screen), screen, cmap,
                         (Pixel *) to->addr, 1);
    }
}


#endif /* USE_X_TOOLKIT */


/* Value is an array of XColor structures for the contents of the
   color map of display DPY.  Set *NCELLS to the size of the array.
   Note that this probably shouldn't be called for large color maps,
   say a 24-bit TrueColor map.  */

static const XColor *
x_color_cells (Display *dpy, int *ncells)
{
  struct x_display_info *dpyinfo = x_display_info_for_display (dpy);
  eassume (dpyinfo);

  if (dpyinfo->color_cells == NULL)
    {
      Screen *screen = dpyinfo->screen;
      int ncolor_cells = XDisplayCells (dpy, XScreenNumberOfScreen (screen));
      int i;

      dpyinfo->color_cells = xnmalloc (ncolor_cells,
                                       sizeof *dpyinfo->color_cells);
      dpyinfo->ncolor_cells = ncolor_cells;

      for (i = 0; i < ncolor_cells; ++i)
        dpyinfo->color_cells[i].pixel = i;

      XQueryColors (dpy, dpyinfo->cmap,
                    dpyinfo->color_cells, ncolor_cells);
    }

  *ncells = dpyinfo->ncolor_cells;
  return dpyinfo->color_cells;
}


/* On frame F, translate pixel colors to RGB values for the NCOLORS
   colors in COLORS.  Use cached information, if available.  */

void
x_query_colors (struct frame *f, XColor *colors, int ncolors)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

  if (dpyinfo->red_bits > 0)
    {
      /* For TrueColor displays, we can decompose the RGB value
         directly.  */
      int i;
      unsigned int rmult, gmult, bmult;
      unsigned int rmask, gmask, bmask;

      rmask = (1 << dpyinfo->red_bits) - 1;
      gmask = (1 << dpyinfo->green_bits) - 1;
      bmask = (1 << dpyinfo->blue_bits) - 1;
      /* If we're widening, for example, 8 bits in the pixel value to
         16 bits for the separate-color representation, we want to
         extrapolate the lower bits based on those bits available --
         in other words, we'd like 0xff to become 0xffff instead of
         the 0xff00 we'd get by just zero-filling the lower bits.

         We generate a 32-bit scaled-up value and shift it, in case
         the bit count doesn't divide 16 evenly (e.g., when dealing
         with a 3-3-2 bit RGB display), to get more of the lower bits
         correct.

         Should we cache the multipliers in dpyinfo?  Maybe
         special-case the 8-8-8 common case?  */
      rmult = 0xffffffff / rmask;
      gmult = 0xffffffff / gmask;
      bmult = 0xffffffff / bmask;

      for (i = 0; i < ncolors; ++i)
        {
          unsigned int r, g, b;
          unsigned long pixel = colors[i].pixel;

          r = (pixel >> dpyinfo->red_offset) & rmask;
          g = (pixel >> dpyinfo->green_offset) & gmask;
          b = (pixel >> dpyinfo->blue_offset) & bmask;

          colors[i].red = (r * rmult) >> 16;
          colors[i].green = (g * gmult) >> 16;
          colors[i].blue = (b * bmult) >> 16;
        }
      return;
    }

  if (dpyinfo->color_cells)
    {
      int i;
      for (i = 0; i < ncolors; ++i)
        {
          unsigned long pixel = colors[i].pixel;
          eassert (pixel < dpyinfo->ncolor_cells);
          eassert (dpyinfo->color_cells[pixel].pixel == pixel);
          colors[i] = dpyinfo->color_cells[pixel];
        }
      return;
    }

  XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), colors, ncolors);
}


/* On frame F, translate pixel color to RGB values for the color in
   COLOR.  Use cached information, if available.  */

void
x_query_color (struct frame *f, XColor *color)
{
  x_query_colors (f, color, 1);
}


/* On frame F, translate the color name to RGB values.  Use cached
   information, if possible.

   Note that there is currently no way to clean old entries out of the
   cache.  However, it is limited to names in the server's database,
   and names we've actually looked up; list-colors-display is probably
   the most color-intensive case we're likely to hit.  */

Status x_parse_color (struct frame *f, const char *color_name,
                      XColor *color)
{
  Display *dpy = FRAME_X_DISPLAY (f);
  Colormap cmap = FRAME_X_COLORMAP (f);
  struct color_name_cache_entry *cache_entry;

  if (color_name[0] == '#')
    {
      /* The hex form is parsed directly by XParseColor without
         talking to the X server.  No need for caching.  */
      return XParseColor (dpy, cmap, color_name, color);
    }

  for (cache_entry = FRAME_DISPLAY_INFO (f)->color_names; cache_entry;
       cache_entry = cache_entry->next)
    {
      if (!xstrcasecmp(cache_entry->name, color_name))
        {
          *color = cache_entry->rgb;
          return 1;
        }
    }

  if (XParseColor (dpy, cmap, color_name, color) == 0)
    /* No caching of negative results, currently.  */
    return 0;

  cache_entry = xzalloc (sizeof *cache_entry);
  cache_entry->rgb = *color;
  cache_entry->name = xstrdup (color_name);
  cache_entry->next = FRAME_DISPLAY_INFO (f)->color_names;
  FRAME_DISPLAY_INFO (f)->color_names = cache_entry;
  return 1;
}


/* Allocate the color COLOR->pixel on DISPLAY, colormap CMAP.  If an
   exact match can't be allocated, try the nearest color available.
   Value is true if successful.  Set *COLOR to the color
   allocated.  */

static bool
x_alloc_nearest_color_1 (Display *dpy, Colormap cmap, XColor *color)
{
  bool rc;

  rc = XAllocColor (dpy, cmap, color) != 0;
  if (rc == 0)
    {
      /* If we got to this point, the colormap is full, so we're going
         to try to get the next closest color.  The algorithm used is
         a least-squares matching, which is what X uses for closest
         color matching with StaticColor visuals.  */
      int nearest, i;
      int max_color_delta = 255;
      int max_delta = 3 * max_color_delta;
      int nearest_delta = max_delta + 1;
      int ncells;
      const XColor *cells = x_color_cells (dpy, &ncells);

      for (nearest = i = 0; i < ncells; ++i)
        {
          int dred   = (color->red   >> 8) - (cells[i].red   >> 8);
          int dgreen = (color->green >> 8) - (cells[i].green >> 8);
          int dblue  = (color->blue  >> 8) - (cells[i].blue  >> 8);
          int delta = dred * dred + dgreen * dgreen + dblue * dblue;

          if (delta < nearest_delta)
            {
              nearest = i;
              nearest_delta = delta;
            }
        }

      color->red   = cells[nearest].red;
      color->green = cells[nearest].green;
      color->blue  = cells[nearest].blue;
      rc = XAllocColor (dpy, cmap, color) != 0;
    }
  else
    {
      /* If allocation succeeded, and the allocated pixel color is not
         equal to a cached pixel color recorded earlier, there was a
         change in the colormap, so clear the color cache.  */
      struct x_display_info *dpyinfo = x_display_info_for_display (dpy);
      eassume (dpyinfo);

      if (dpyinfo->color_cells)
        {
          XColor *cached_color = &dpyinfo->color_cells[color->pixel];
          if (cached_color->red != color->red
              || cached_color->blue != color->blue
              || cached_color->green != color->green)
            {
              xfree (dpyinfo->color_cells);
              dpyinfo->color_cells = NULL;
              dpyinfo->ncolor_cells = 0;
            }
        }
    }

#ifdef DEBUG_X_COLORS
  if (rc)
    register_color (color->pixel);
#endif /* DEBUG_X_COLORS */

  return rc;
}


/* Allocate the color COLOR->pixel on frame F, colormap CMAP, after
   gamma correction.  If an exact match can't be allocated, try the
   nearest color available.  Value is true if successful.  Set *COLOR
   to the color allocated.  */

bool
x_alloc_nearest_color (struct frame *f, Colormap cmap, XColor *color)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

  gamma_correct (f, color);

  if (dpyinfo->red_bits > 0)
    {
      color->pixel = x_make_truecolor_pixel (dpyinfo,
                                             color->red,
                                             color->green,
                                             color->blue);
      return true;
    }

  return x_alloc_nearest_color_1 (FRAME_X_DISPLAY (f), cmap, color);
}


/* Allocate color PIXEL on frame F.  PIXEL must already be allocated.
   It's necessary to do this instead of just using PIXEL directly to
   get color reference counts right.  */

unsigned long
x_copy_color (struct frame *f, unsigned long pixel)
{
  XColor color;

  /* If display has an immutable color map, freeing colors is not
     necessary and some servers don't allow it.  Since we won't free a
     color once we've allocated it, we don't need to re-allocate it to
     maintain the server's reference count.  */
  if (!x_mutable_colormap (FRAME_X_VISUAL (f)))
    return pixel;

  color.pixel = pixel;
  block_input ();
  /* The color could still be found in the color_cells array.  */
  x_query_color (f, &color);
  XAllocColor (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), &color);
  unblock_input ();
#ifdef DEBUG_X_COLORS
  register_color (pixel);
#endif
  return color.pixel;
}


/* Brightness beyond which a color won't have its highlight brightness
   boosted.

   Nominally, highlight colors for `3d' faces are calculated by
   brightening an object's color by a constant scale factor, but this
   doesn't yield good results for dark colors, so for colors who's
   brightness is less than this value (on a scale of 0-65535) have an
   use an additional additive factor.

   The value here is set so that the default menu-bar/mode-line color
   (grey75) will not have its highlights changed at all.  */
#define HIGHLIGHT_COLOR_DARK_BOOST_LIMIT 48000


/* Allocate a color which is lighter or darker than *PIXEL by FACTOR
   or DELTA.  Try a color with RGB values multiplied by FACTOR first.
   If this produces the same color as PIXEL, try a color where all RGB
   values have DELTA added.  Return the allocated color in *PIXEL.
   DISPLAY is the X display, CMAP is the colormap to operate on.
   Value is non-zero if successful.  */

static bool
x_alloc_lighter_color (struct frame *f, Display *display, Colormap cmap,
                       unsigned long *pixel, double factor, int delta)
{
  XColor color, new;
  long bright;
  bool success_p;

  /* Get RGB color values.  */
  color.pixel = *pixel;
  x_query_color (f, &color);

  /* Change RGB values by specified FACTOR.  Avoid overflow!  */
  eassert (factor >= 0);
  new.red = min (0xffff, factor * color.red);
  new.green = min (0xffff, factor * color.green);
  new.blue = min (0xffff, factor * color.blue);

  /* Calculate brightness of COLOR.  */
  bright = (2 * color.red + 3 * color.green + color.blue) / 6;

  /* We only boost colors that are darker than
     HIGHLIGHT_COLOR_DARK_BOOST_LIMIT.  */
  if (bright < HIGHLIGHT_COLOR_DARK_BOOST_LIMIT)
    /* Make an additive adjustment to NEW, because it's dark enough so
       that scaling by FACTOR alone isn't enough.  */
    {
      /* How far below the limit this color is (0 - 1, 1 being darker).  */
      double dimness = 1 - (double)bright / HIGHLIGHT_COLOR_DARK_BOOST_LIMIT;
      /* The additive adjustment.  */
      int min_delta = delta * dimness * factor / 2;

      if (factor < 1)
        {
          new.red =   max (0, new.red -   min_delta);
          new.green = max (0, new.green - min_delta);
          new.blue =  max (0, new.blue -  min_delta);
        }
      else
        {
          new.red =   min (0xffff, min_delta + new.red);
          new.green = min (0xffff, min_delta + new.green);
          new.blue =  min (0xffff, min_delta + new.blue);
        }
    }

  /* Try to allocate the color.  */
  success_p = x_alloc_nearest_color (f, cmap, &new);
  if (success_p)
    {
      if (new.pixel == *pixel)
        {
          /* If we end up with the same color as before, try adding
             delta to the RGB values.  */
          x_free_colors (f, &new.pixel, 1);

          new.red = min (0xffff, delta + color.red);
          new.green = min (0xffff, delta + color.green);
          new.blue = min (0xffff, delta + color.blue);
          success_p = x_alloc_nearest_color (f, cmap, &new);
        }
      else
        success_p = true;
      *pixel = new.pixel;
    }

  return success_p;
}


/* Set up the foreground color for drawing relief lines of glyph
   string S.  RELIEF is a pointer to a struct relief containing the GC
   with which lines will be drawn.  Use a color that is FACTOR or
   DELTA lighter or darker than the relief's background which is found
   in S->f->output_data.x->relief_background.  If such a color cannot
   be allocated, use DEFAULT_PIXEL, instead.  */

static void
x_setup_relief_color (struct frame *f, struct relief *relief, double factor,
                      int delta, unsigned long default_pixel)
{
  XGCValues xgcv;
  struct x_output *di = f->output_data.x;
  unsigned long mask = GCForeground | GCLineWidth | GCGraphicsExposures;
  unsigned long pixel;
  unsigned long background = di->relief_background;
  Colormap cmap = FRAME_X_COLORMAP (f);
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
  Display *dpy = FRAME_X_DISPLAY (f);

  xgcv.graphics_exposures = False;
  xgcv.line_width = 1;

  /* Free previously allocated color.  The color cell will be reused
     when it has been freed as many times as it was allocated, so this
     doesn't affect faces using the same colors.  */
  if (relief->gc && relief->pixel != -1)
    {
      x_free_colors (f, &relief->pixel, 1);
      relief->pixel = -1;
    }

  /* Allocate new color.  */
  xgcv.foreground = default_pixel;
  pixel = background;
  if (dpyinfo->n_planes != 1
      && x_alloc_lighter_color (f, dpy, cmap, &pixel, factor, delta))
    xgcv.foreground = relief->pixel = pixel;

  if (relief->gc == 0)
    {
      xgcv.stipple = dpyinfo->gray;
      mask |= GCStipple;
      relief->gc = XCreateGC (dpy, FRAME_X_DRAWABLE (f), mask, &xgcv);
    }
  else
    XChangeGC (dpy, relief->gc, mask, &xgcv);
}


/* Set up colors for the relief lines around glyph string S.  */

static void
x_setup_relief_colors (struct glyph_string *s)
{
  struct x_output *di = s->f->output_data.x;
  unsigned long color;

  if (s->face->use_box_color_for_shadows_p)
    color = s->face->box_color;
  else if (s->first_glyph->type == IMAGE_GLYPH
           && s->img->pixmap
           && !IMAGE_BACKGROUND_TRANSPARENT (s->img, s->f, 0))
    color = IMAGE_BACKGROUND (s->img, s->f, 0);
  else
    {
      XGCValues xgcv;

      /* Get the background color of the face.  */
      XGetGCValues (s->display, s->gc, GCBackground, &xgcv);
      color = xgcv.background;
    }

  if (di->white_relief.gc == 0
      || color != di->relief_background)
    {
      di->relief_background = color;
      x_setup_relief_color (s->f, &di->white_relief, 1.2, 0x8000,
                            WHITE_PIX_DEFAULT (s->f));
      x_setup_relief_color (s->f, &di->black_relief, 0.6, 0x4000,
                            BLACK_PIX_DEFAULT (s->f));
    }
}


/* Draw a relief on frame F inside the rectangle given by LEFT_X,
   TOP_Y, RIGHT_X, and BOTTOM_Y.  WIDTH is the thickness of the relief
   to draw, it must be >= 0.  RAISED_P means draw a raised
   relief.  LEFT_P means draw a relief on the left side of
   the rectangle.  RIGHT_P means draw a relief on the right
   side of the rectangle.  CLIP_RECT is the clipping rectangle to use
   when drawing.  */

static void
x_draw_relief_rect (struct frame *f,
                    int left_x, int top_y, int right_x, int bottom_y,
                    int width, bool raised_p, bool top_p, bool bot_p,
                    bool left_p, bool right_p,
                    XRectangle *clip_rect)
{
#ifdef USE_CAIRO
  GC top_left_gc, bottom_right_gc;
  int corners = 0;

  if (raised_p)
    {
      top_left_gc = f->output_data.x->white_relief.gc;
      bottom_right_gc = f->output_data.x->black_relief.gc;
    }
  else
    {
      top_left_gc = f->output_data.x->black_relief.gc;
      bottom_right_gc = f->output_data.x->white_relief.gc;
    }

  x_set_clip_rectangles (f, top_left_gc, clip_rect, 1);
  x_set_clip_rectangles (f, bottom_right_gc, clip_rect, 1);

  if (left_p)
    {
      x_fill_rectangle (f, top_left_gc, left_x, top_y,
                        width, bottom_y + 1 - top_y);
      if (top_p)
        corners |= 1 << CORNER_TOP_LEFT;
      if (bot_p)
        corners |= 1 << CORNER_BOTTOM_LEFT;
    }
  if (right_p)
    {
      x_fill_rectangle (f, bottom_right_gc, right_x + 1 - width, top_y,
                        width, bottom_y + 1 - top_y);
      if (top_p)
        corners |= 1 << CORNER_TOP_RIGHT;
      if (bot_p)
        corners |= 1 << CORNER_BOTTOM_RIGHT;
    }
  if (top_p)
    {
      if (!right_p)
        x_fill_rectangle (f, top_left_gc, left_x, top_y,
                          right_x + 1 - left_x, width);
      else
        x_fill_trapezoid_for_relief (f, top_left_gc, left_x, top_y,
                                     right_x + 1 - left_x, width, 1);
    }
  if (bot_p)
    {
      if (!left_p)
        x_fill_rectangle (f, bottom_right_gc, left_x, bottom_y + 1 - width,
                          right_x + 1 - left_x, width);
      else
        x_fill_trapezoid_for_relief (f, bottom_right_gc,
                                     left_x, bottom_y + 1 - width,
                                     right_x + 1 - left_x, width, 0);
    }
  if (left_p && width != 1)
    x_fill_rectangle (f, bottom_right_gc, left_x, top_y,
                      1, bottom_y + 1 - top_y);
  if (top_p && width != 1)
    x_fill_rectangle (f, bottom_right_gc, left_x, top_y,
                      right_x + 1 - left_x, 1);
  if (corners)
    {
      XSetBackground (FRAME_X_DISPLAY (f), top_left_gc,
                      FRAME_BACKGROUND_PIXEL (f));
      x_erase_corners_for_relief (f, top_left_gc, left_x, top_y,
                                  right_x - left_x + 1, bottom_y - top_y + 1,
                                  6, 1, corners);
    }

  x_reset_clip_rectangles (f, top_left_gc);
  x_reset_clip_rectangles (f, bottom_right_gc);
#else
  Display *dpy = FRAME_X_DISPLAY (f);
  Drawable drawable = FRAME_X_DRAWABLE (f);
  int i;
  GC gc;

  if (raised_p)
    gc = f->output_data.x->white_relief.gc;
  else
    gc = f->output_data.x->black_relief.gc;
  XSetClipRectangles (dpy, gc, 0, 0, clip_rect, 1, Unsorted);

  /* This code is more complicated than it has to be, because of two
     minor hacks to make the boxes look nicer: (i) if width > 1, draw
     the outermost line using the black relief.  (ii) Omit the four
     corner pixels.  */

  /* Top.  */
  if (top_p)
    {
      if (width == 1)
        XDrawLine (dpy, drawable, gc,
                   left_x + left_p, top_y,
                   right_x + !right_p, top_y);

      for (i = 1; i < width; ++i)
        XDrawLine (dpy, drawable, gc,
                   left_x  + i * left_p, top_y + i,
                   right_x + 1 - i * right_p, top_y + i);
    }

  /* Left.  */
  if (left_p)
    {
      if (width == 1)
        XDrawLine (dpy, drawable, gc, left_x, top_y + 1, left_x, bottom_y);

      x_clear_area(f, left_x, top_y, 1, 1);
      x_clear_area(f, left_x, bottom_y, 1, 1);

      for (i = (width > 1 ? 1 : 0); i < width; ++i)
        XDrawLine (dpy, drawable, gc,
                   left_x + i, top_y + (i + 1) * top_p,
                   left_x + i, bottom_y + 1 - (i + 1) * bot_p);
    }

  XSetClipMask (dpy, gc, None);
  if (raised_p)
    gc = f->output_data.x->black_relief.gc;
  else
    gc = f->output_data.x->white_relief.gc;
  XSetClipRectangles (dpy, gc, 0, 0, clip_rect, 1, Unsorted);

  if (width > 1)
    {
      /* Outermost top line.  */
      if (top_p)
        XDrawLine (dpy, drawable, gc,
                   left_x  + left_p, top_y,
                   right_x + !right_p, top_y);

      /* Outermost left line.  */
      if (left_p)
        XDrawLine (dpy, drawable, gc, left_x, top_y + 1, left_x, bottom_y);
    }

  /* Bottom.  */
  if (bot_p)
    {
      XDrawLine (dpy, drawable, gc,
                 left_x + left_p, bottom_y,
                 right_x + !right_p, bottom_y);
      for (i = 1; i < width; ++i)
        XDrawLine (dpy, drawable, gc,
                   left_x  + i * left_p, bottom_y - i,
                   right_x + 1 - i * right_p, bottom_y - i);
    }

  /* Right.  */
  if (right_p)
    {
      x_clear_area(f, right_x, top_y, 1, 1);
      x_clear_area(f, right_x, bottom_y, 1, 1);
      for (i = 0; i < width; ++i)
        XDrawLine (dpy, drawable, gc,
                   right_x - i, top_y + (i + 1) * top_p,
                   right_x - i, bottom_y + 1 - (i + 1) * bot_p);
    }

  x_reset_clip_rectangles (f, gc);

#endif
}


/* Draw a box on frame F inside the rectangle given by LEFT_X, TOP_Y,
   RIGHT_X, and BOTTOM_Y.  WIDTH is the thickness of the lines to
   draw, it must be >= 0.  LEFT_P means draw a line on the
   left side of the rectangle.  RIGHT_P means draw a line
   on the right side of the rectangle.  CLIP_RECT is the clipping
   rectangle to use when drawing.  */

static void
x_draw_box_rect (struct glyph_string *s,
                 int left_x, int top_y, int right_x, int bottom_y, int width,
                 bool left_p, bool right_p, XRectangle *clip_rect)
{
  XGCValues xgcv;

  XGetGCValues (s->display, s->gc, GCForeground, &xgcv);
  XSetForeground (s->display, s->gc, s->face->box_color);
  x_set_clip_rectangles (s->f, s->gc, clip_rect, 1);

  /* Top.  */
  x_fill_rectangle (s->f, s->gc,
                  left_x, top_y, right_x - left_x + 1, width);

  /* Left.  */
  if (left_p)
    x_fill_rectangle (s->f, s->gc,
                    left_x, top_y, width, bottom_y - top_y + 1);

  /* Bottom.  */
  x_fill_rectangle (s->f, s->gc,
                  left_x, bottom_y - width + 1, right_x - left_x + 1, width);

  /* Right.  */
  if (right_p)
    x_fill_rectangle (s->f, s->gc,
                    right_x - width + 1, top_y, width, bottom_y - top_y + 1);

  XSetForeground (s->display, s->gc, xgcv.foreground);
  x_reset_clip_rectangles (s->f, s->gc);
}


/* Draw a box around glyph string S.  */

static void
x_draw_glyph_string_box (struct glyph_string *s)
{
  int width, left_x, right_x, top_y, bottom_y, last_x;
  bool raised_p, left_p, right_p;
  struct glyph *last_glyph;
  XRectangle clip_rect;

  last_x = ((s->row->full_width_p && !s->w->pseudo_window_p)
            ? WINDOW_RIGHT_EDGE_X (s->w)
            : window_box_right (s->w, s->area));

  /* The glyph that may have a right box line.  */
  last_glyph = (s->cmp || s->img
                ? s->first_glyph
                : s->first_glyph + s->nchars - 1);

  width = eabs (s->face->box_line_width);
  raised_p = s->face->box == FACE_RAISED_BOX;
  left_x = s->x;
  right_x = (s->row->full_width_p && s->extends_to_end_of_line_p
             ? last_x - 1
             : min (last_x, s->x + s->background_width) - 1);
  top_y = s->y;
  bottom_y = top_y + s->height - 1;

  left_p = (s->first_glyph->left_box_line_p
            || (s->hl == DRAW_MOUSE_FACE
                && (s->prev == NULL
                    || s->prev->hl != s->hl)));
  right_p = (last_glyph->right_box_line_p
             || (s->hl == DRAW_MOUSE_FACE
                 && (s->next == NULL
                     || s->next->hl != s->hl)));

  get_glyph_string_clip_rect (s, &clip_rect);

  if (s->face->box == FACE_SIMPLE_BOX)
    x_draw_box_rect (s, left_x, top_y, right_x, bottom_y, width,
                     left_p, right_p, &clip_rect);
  else
    {
      x_setup_relief_colors (s);
      x_draw_relief_rect (s->f, left_x, top_y, right_x, bottom_y,
                          width, raised_p, true, true, left_p, right_p,
                          &clip_rect);
    }
}


/* Draw foreground of image glyph string S.  */

static void
x_draw_image_foreground (struct glyph_string *s)
{
  int x = s->x;
  int y = s->ybase - image_ascent (s->img, s->face, &s->slice);

  /* If first glyph of S has a left box line, start drawing it to the
     right of that line.  */
  if (s->face->box != FACE_NO_BOX
      && s->first_glyph->left_box_line_p
      && s->slice.x == 0)
    x += eabs (s->face->box_line_width);

  /* If there is a margin around the image, adjust x- and y-position
     by that margin.  */
  if (s->slice.x == 0)
    x += s->img->hmargin;
  if (s->slice.y == 0)
    y += s->img->vmargin;

  if (s->img->pixmap)
    {
      if (s->img->mask)
        {
          /* We can't set both a clip mask and use XSetClipRectangles
             because the latter also sets a clip mask.  We also can't
             trust on the shape extension to be available
             (XShapeCombineRegion).  So, compute the rectangle to draw
             manually.  */
          unsigned long mask = (GCClipMask | GCClipXOrigin | GCClipYOrigin
                                | GCFunction);
          XGCValues xgcv;
          XRectangle clip_rect, image_rect, r;

          xgcv.clip_mask = s->img->mask;
          xgcv.clip_x_origin = x;
          xgcv.clip_y_origin = y;
          xgcv.function = GXcopy;
          XChangeGC (s->display, s->gc, mask, &xgcv);

          get_glyph_string_clip_rect (s, &clip_rect);
          image_rect.x = x;
          image_rect.y = y;
          image_rect.width = s->slice.width;
          image_rect.height = s->slice.height;
          if (x_intersect_rectangles (&clip_rect, &image_rect, &r))
            XCopyArea (s->display, s->img->pixmap,
                       FRAME_X_DRAWABLE (s->f), s->gc,
                       s->slice.x + r.x - x, s->slice.y + r.y - y,
                       r.width, r.height, r.x, r.y);
        }
      else
        {
          XRectangle clip_rect, image_rect, r;

          get_glyph_string_clip_rect (s, &clip_rect);
          image_rect.x = x;
          image_rect.y = y;
          image_rect.width = s->slice.width;
          image_rect.height = s->slice.height;
          if (x_intersect_rectangles (&clip_rect, &image_rect, &r))
            XCopyArea (s->display, s->img->pixmap,
                       FRAME_X_DRAWABLE (s->f), s->gc,
                       s->slice.x + r.x - x, s->slice.y + r.y - y,
                       r.width, r.height, r.x, r.y);

          /* When the image has a mask, we can expect that at
             least part of a mouse highlight or a block cursor will
             be visible.  If the image doesn't have a mask, make
             a block cursor visible by drawing a rectangle around
             the image.  I believe it's looking better if we do
             nothing here for mouse-face.  */
          if (s->hl == DRAW_CURSOR)
            {
              int relief = eabs (s->img->relief);
              x_draw_rectangle (s->f, s->gc,
                              x - relief, y - relief,
                              s->slice.width + relief*2 - 1,
                              s->slice.height + relief*2 - 1);
            }
        }
    }
  else
    /* Draw a rectangle if image could not be loaded.  */
    x_draw_rectangle (s->f, s->gc, x, y,
                    s->slice.width - 1, s->slice.height - 1);
}


/* Draw a relief around the image glyph string S.  */

static void
x_draw_image_relief (struct glyph_string *s)
{
  int x1, y1, thick;
  bool raised_p, top_p, bot_p, left_p, right_p;
  int extra_x, extra_y;
  XRectangle r;
  int x = s->x;
  int y = s->ybase - image_ascent (s->img, s->face, &s->slice);

  /* If first glyph of S has a left box line, start drawing it to the
     right of that line.  */
  if (s->face->box != FACE_NO_BOX
      && s->first_glyph->left_box_line_p
      && s->slice.x == 0)
    x += eabs (s->face->box_line_width);

  /* If there is a margin around the image, adjust x- and y-position
     by that margin.  */
  if (s->slice.x == 0)
    x += s->img->hmargin;
  if (s->slice.y == 0)
    y += s->img->vmargin;

  if (s->hl == DRAW_IMAGE_SUNKEN
      || s->hl == DRAW_IMAGE_RAISED)
    {
      thick = tool_bar_button_relief >= 0 ? tool_bar_button_relief : DEFAULT_TOOL_BAR_BUTTON_RELIEF;
      raised_p = s->hl == DRAW_IMAGE_RAISED;
    }
  else
    {
      thick = eabs (s->img->relief);
      raised_p = s->img->relief > 0;
    }

  x1 = x + s->slice.width - 1;
  y1 = y + s->slice.height - 1;

  extra_x = extra_y = 0;
  if (s->face->id == TOOL_BAR_FACE_ID)
    {
      if (CONSP (Vtool_bar_button_margin)
          && INTEGERP (XCAR (Vtool_bar_button_margin))
          && INTEGERP (XCDR (Vtool_bar_button_margin)))
        {
          extra_x = XINT (XCAR (Vtool_bar_button_margin));
          extra_y = XINT (XCDR (Vtool_bar_button_margin));
        }
      else if (INTEGERP (Vtool_bar_button_margin))
        extra_x = extra_y = XINT (Vtool_bar_button_margin);
    }

  top_p = bot_p = left_p = right_p = false;

  if (s->slice.x == 0)
    x -= thick + extra_x, left_p = true;
  if (s->slice.y == 0)
    y -= thick + extra_y, top_p = true;
  if (s->slice.x + s->slice.width == s->img->width)
    x1 += thick + extra_x, right_p = true;
  if (s->slice.y + s->slice.height == s->img->height)
    y1 += thick + extra_y, bot_p = true;

  x_setup_relief_colors (s);
  get_glyph_string_clip_rect (s, &r);
  x_draw_relief_rect (s->f, x, y, x1, y1, thick, raised_p,
                      top_p, bot_p, left_p, right_p, &r);
}


/* Draw the foreground of image glyph string S to PIXMAP.  */

static void
x_draw_image_foreground_1 (struct glyph_string *s, Pixmap pixmap)
{
  int x = 0;
  int y = s->ybase - s->y - image_ascent (s->img, s->face, &s->slice);

  /* If first glyph of S has a left box line, start drawing it to the
     right of that line.  */
  if (s->face->box != FACE_NO_BOX
      && s->first_glyph->left_box_line_p
      && s->slice.x == 0)
    x += eabs (s->face->box_line_width);

  /* If there is a margin around the image, adjust x- and y-position
     by that margin.  */
  if (s->slice.x == 0)
    x += s->img->hmargin;
  if (s->slice.y == 0)
    y += s->img->vmargin;

  if (s->img->pixmap)
    {
      if (s->img->mask)
        {
          /* We can't set both a clip mask and use XSetClipRectangles
             because the latter also sets a clip mask.  We also can't
             trust on the shape extension to be available
             (XShapeCombineRegion).  So, compute the rectangle to draw
             manually.  */
          unsigned long mask = (GCClipMask | GCClipXOrigin | GCClipYOrigin
                                | GCFunction);
          XGCValues xgcv;

          xgcv.clip_mask = s->img->mask;
          xgcv.clip_x_origin = x - s->slice.x;
          xgcv.clip_y_origin = y - s->slice.y;
          xgcv.function = GXcopy;
          XChangeGC (s->display, s->gc, mask, &xgcv);

          XCopyArea (s->display, s->img->pixmap, pixmap, s->gc,
                     s->slice.x, s->slice.y,
                     s->slice.width, s->slice.height, x, y);
          XSetClipMask (s->display, s->gc, None);
        }
      else
        {
          XCopyArea (s->display, s->img->pixmap, pixmap, s->gc,
                     s->slice.x, s->slice.y,
                     s->slice.width, s->slice.height, x, y);

          /* When the image has a mask, we can expect that at
             least part of a mouse highlight or a block cursor will
             be visible.  If the image doesn't have a mask, make
             a block cursor visible by drawing a rectangle around
             the image.  I believe it's looking better if we do
             nothing here for mouse-face.  */
          if (s->hl == DRAW_CURSOR)
            {
              int r = eabs (s->img->relief);
              x_draw_rectangle (s->f, s->gc, x - r, y - r,
                              s->slice.width + r*2 - 1,
                              s->slice.height + r*2 - 1);
            }
        }
    }
  else
    /* Draw a rectangle if image could not be loaded.  */
    x_draw_rectangle (s->f, s->gc, x, y,
                    s->slice.width - 1, s->slice.height - 1);
}


/* Draw part of the background of glyph string S.  X, Y, W, and H
   give the rectangle to draw.  */

static void
x_draw_glyph_string_bg_rect (struct glyph_string *s, int x, int y, int w, int h)
{
  if (s->stippled_p)
    {
      /* Fill background with a stipple pattern.  */
      XSetFillStyle (s->display, s->gc, FillOpaqueStippled);
      x_fill_rectangle (s->f, s->gc, x, y, w, h);
      XSetFillStyle (s->display, s->gc, FillSolid);
    }
  else
    x_clear_glyph_string_rect (s, x, y, w, h);
}


/* Draw image glyph string S.

            s->y
   s->x      +-------------------------
             |   s->face->box
             |
             |     +-------------------------
             |     |  s->img->margin
             |     |
             |     |       +-------------------
             |     |       |  the image

 */

static void
x_draw_image_glyph_string (struct glyph_string *s)
{
  int box_line_hwidth = eabs (s->face->box_line_width);
  int box_line_vwidth = max (s->face->box_line_width, 0);
  int height;
  Pixmap pixmap = None;

  height = s->height;
  if (s->slice.y == 0)
    height -= box_line_vwidth;
  if (s->slice.y + s->slice.height >= s->img->height)
    height -= box_line_vwidth;

  /* Fill background with face under the image.  Do it only if row is
     taller than image or if image has a clip mask to reduce
     flickering.  */
  s->stippled_p = s->face->stipple != 0;
  if (height > s->slice.height
      || s->img->hmargin
      || s->img->vmargin
      || s->img->mask
      || s->img->pixmap == 0
      || s->width != s->background_width)
    {
      if (s->img->mask)
        {
          /* Create a pixmap as large as the glyph string.  Fill it
             with the background color.  Copy the image to it, using
             its mask.  Copy the temporary pixmap to the display.  */
          Screen *screen = FRAME_X_SCREEN (s->f);
          int depth = DefaultDepthOfScreen (screen);

          /* Create a pixmap as large as the glyph string.  */
          pixmap = XCreatePixmap (s->display, FRAME_X_DRAWABLE (s->f),
                                  s->background_width,
                                  s->height, depth);

          /* Don't clip in the following because we're working on the
             pixmap.  */
          XSetClipMask (s->display, s->gc, None);

          /* Fill the pixmap with the background color/stipple.  */
          if (s->stippled_p)
            {
              /* Fill background with a stipple pattern.  */
              XSetFillStyle (s->display, s->gc, FillOpaqueStippled);
              XSetTSOrigin (s->display, s->gc, - s->x, - s->y);
              XFillRectangle (s->display, pixmap, s->gc,
                              0, 0, s->background_width, s->height);
              XSetFillStyle (s->display, s->gc, FillSolid);
              XSetTSOrigin (s->display, s->gc, 0, 0);
            }
          else
            {
              XGCValues xgcv;
              XGetGCValues (s->display, s->gc, GCForeground | GCBackground,
                            &xgcv);
              XSetForeground (s->display, s->gc, xgcv.background);
              XFillRectangle (s->display, pixmap, s->gc,
                              0, 0, s->background_width, s->height);
              XSetForeground (s->display, s->gc, xgcv.foreground);
            }
        }
      else
        {
          int x = s->x;
          int y = s->y;
          int width = s->background_width;

          if (s->first_glyph->left_box_line_p
              && s->slice.x == 0)
            {
              x += box_line_hwidth;
              width -= box_line_hwidth;
            }

          if (s->slice.y == 0)
            y += box_line_vwidth;

          x_draw_glyph_string_bg_rect (s, x, y, width, height);
        }

      s->background_filled_p = true;
    }

  /* Draw the foreground.  */
#ifdef USE_CAIRO
  if (s->img->cr_data)
    {
      cairo_t *cr = x_begin_cr_clip (s->f, s->gc);

      int x = s->x + s->img->hmargin;
      int y = s->y + s->img->vmargin;
      int width = s->background_width;

      cairo_set_source_surface (cr, s->img->cr_data,
                                x - s->slice.x,
                                y - s->slice.y);
      cairo_rectangle (cr, x, y, width, height);
      cairo_fill (cr);
      x_end_cr_clip (s->f);
    }
  else
#endif
    if (pixmap != None)
    {
      x_draw_image_foreground_1 (s, pixmap);
      x_set_glyph_string_clipping (s);
      XCopyArea (s->display, pixmap, FRAME_X_DRAWABLE (s->f), s->gc,
                 0, 0, s->background_width, s->height, s->x, s->y);
      XFreePixmap (s->display, pixmap);
    }
  else
    x_draw_image_foreground (s);

  /* If we must draw a relief around the image, do it.  */
  if (s->img->relief
      || s->hl == DRAW_IMAGE_RAISED
      || s->hl == DRAW_IMAGE_SUNKEN)
    x_draw_image_relief (s);
}


/* Draw stretch glyph string S.  */

static void
x_draw_stretch_glyph_string (struct glyph_string *s)
{
  eassert (s->first_glyph->type == STRETCH_GLYPH);

  if (s->hl == DRAW_CURSOR
      && !x_stretch_cursor_p)
    {
      /* If `x-stretch-cursor' is nil, don't draw a block cursor as
         wide as the stretch glyph.  */
      int width, background_width = s->background_width;
      int x = s->x;

      if (!s->row->reversed_p)
        {
          int left_x = window_box_left_offset (s->w, TEXT_AREA);

          if (x < left_x)
            {
              background_width -= left_x - x;
              x = left_x;
            }
        }
      else
        {
          /* In R2L rows, draw the cursor on the right edge of the
             stretch glyph.  */
          int right_x = window_box_right (s->w, TEXT_AREA);

          if (x + background_width > right_x)
            background_width -= x - right_x;
          x += background_width;
        }
      width = min (FRAME_COLUMN_WIDTH (s->f), background_width);
      if (s->row->reversed_p)
        x -= width;

      /* Draw cursor.  */
      x_draw_glyph_string_bg_rect (s, x, s->y, width, s->height);

      /* Clear rest using the GC of the original non-cursor face.  */
      if (width < background_width)
        {
          int y = s->y;
          int w = background_width - width, h = s->height;
          XRectangle r;
          GC gc;

          if (!s->row->reversed_p)
            x += width;
          else
            x = s->x;
          if (s->row->mouse_face_p
              && cursor_in_mouse_face_p (s->w))
            {
              x_set_mouse_face_gc (s);
              gc = s->gc;
            }
          else
            gc = s->face->gc;

          get_glyph_string_clip_rect (s, &r);
          x_set_clip_rectangles (s->f, gc, &r, 1);

          if (s->face->stipple)
            {
              /* Fill background with a stipple pattern.  */
              XSetFillStyle (s->display, gc, FillOpaqueStippled);
              x_fill_rectangle (s->f, gc, x, y, w, h);
              XSetFillStyle (s->display, gc, FillSolid);
            }
          else
            {
              XGCValues xgcv;
              XGetGCValues (s->display, gc, GCForeground | GCBackground, &xgcv);
              XSetForeground (s->display, gc, xgcv.background);
              x_fill_rectangle (s->f, gc, x, y, w, h);
              XSetForeground (s->display, gc, xgcv.foreground);
            }

          x_reset_clip_rectangles (s->f, gc);
        }
    }
  else if (!s->background_filled_p)
    {
      int background_width = s->background_width;
      int x = s->x, left_x = window_box_left_offset (s->w, TEXT_AREA);

      /* Don't draw into left margin, fringe or scrollbar area
         except for header line and mode line.  */
      if (x < left_x && !s->row->mode_line_p)
        {
          background_width -= left_x - x;
          x = left_x;
        }
      if (background_width > 0)
        x_draw_glyph_string_bg_rect (s, x, s->y, background_width, s->height);
    }

  s->background_filled_p = true;
}

static void
x_get_scale_factor(Display *disp, int *scale_x, int *scale_y)
{
  const int base_res = 96;
  struct x_display_info * dpyinfo = x_display_info_for_display (disp);

  *scale_x = *scale_y = 1;

  if (dpyinfo)
    {
      *scale_x = floor (dpyinfo->resx / base_res);
      *scale_y = floor (dpyinfo->resy / base_res);
    }
}

/*
   Draw a wavy line under S. The wave fills wave_height pixels from y0.

                    x0         wave_length = 2
                                 --
                y0   *   *   *   *   *
                     |* * * * * * * * *
    wave_height = 3  | *   *   *   *

*/
static void
x_draw_underwave (struct glyph_string *s)
{
  /* Adjust for scale/HiDPI.  */
  int scale_x, scale_y;

  x_get_scale_factor (s->display, &scale_x, &scale_y);

  int wave_height = 3 * scale_y, wave_length = 2 * scale_x, thickness = scale_y;

#ifdef USE_CAIRO
  x_draw_horizontal_wave (s->f, s->gc, s->x, s->ybase - wave_height + 3,
                          s->width, wave_height, wave_length);
#else  /* not USE_CAIRO */
  int dx, dy, x0, y0, width, x1, y1, x2, y2, xmax;
  bool odd;
  XRectangle wave_clip, string_clip, final_clip;

  dx = wave_length;
  dy = wave_height - 1;
  x0 = s->x;
  y0 = s->ybase + wave_height / 2;
  width = s->width;
  xmax = x0 + width;

  /* Find and set clipping rectangle */

  wave_clip.x = x0;
  wave_clip.y = y0;
  wave_clip.width = width;
  wave_clip.height = wave_height;
  get_glyph_string_clip_rect (s, &string_clip);

  if (!x_intersect_rectangles (&wave_clip, &string_clip, &final_clip))
    return;

  XSetClipRectangles (s->display, s->gc, 0, 0, &final_clip, 1, Unsorted);

  /* Draw the waves */

  x1 = x0 - (x0 % dx);
  x2 = x1 + dx;
  odd = (x1 / dx) & 1;
  y1 = y2 = y0;

  if (odd)
    y1 += dy;
  else
    y2 += dy;

  if (INT_MAX - dx < xmax)
    emacs_abort ();

  while (x1 <= xmax)
    {
      XSetLineAttributes (s->display, s->gc, thickness, LineSolid, CapButt,
                          JoinRound);
      XDrawLine (s->display, FRAME_X_DRAWABLE (s->f), s->gc, x1, y1, x2, y2);
      x1  = x2, y1 = y2;
      x2 += dx, y2 = y0 + odd*dy;
      odd = !odd;
    }

  /* Restore previous clipping rectangle(s) */
  XSetClipRectangles (s->display, s->gc, 0, 0, s->clip, s->num_clips, Unsorted);
#endif  /* not USE_CAIRO */
}


/* Draw glyph string S.  */

static void
x_draw_glyph_string (struct glyph_string *s)
{
  bool relief_drawn_p = false;

  /* If S draws into the background of its successors, draw the
     background of the successors first so that S can draw into it.
     This makes S->next use XDrawString instead of XDrawImageString.  */
  if (s->next && s->right_overhang && !s->for_overlaps)
    {
      int width;
      struct glyph_string *next;

      for (width = 0, next = s->next;
           next && width < s->right_overhang;
           width += next->width, next = next->next)
        if (next->first_glyph->type != IMAGE_GLYPH)
          {
            x_set_glyph_string_gc (next);
            x_set_glyph_string_clipping (next);
            if (next->first_glyph->type == STRETCH_GLYPH)
              x_draw_stretch_glyph_string (next);
            else
              x_draw_glyph_string_background (next, true);
            next->num_clips = 0;
          }
    }

  /* Set up S->gc, set clipping and draw S.  */
  x_set_glyph_string_gc (s);

  /* Draw relief (if any) in advance for char/composition so that the
     glyph string can be drawn over it.  */
  if (!s->for_overlaps
      && s->face->box != FACE_NO_BOX
      && (s->first_glyph->type == CHAR_GLYPH
          || s->first_glyph->type == COMPOSITE_GLYPH))

    {
      x_set_glyph_string_clipping (s);
      x_draw_glyph_string_background (s, true);
      x_draw_glyph_string_box (s);
      x_set_glyph_string_clipping (s);
      relief_drawn_p = true;
    }
  else if (!s->clip_head /* draw_glyphs didn't specify a clip mask. */
           && !s->clip_tail
           && ((s->prev && s->prev->hl != s->hl && s->left_overhang)
               || (s->next && s->next->hl != s->hl && s->right_overhang)))
    /* We must clip just this glyph.  left_overhang part has already
       drawn when s->prev was drawn, and right_overhang part will be
       drawn later when s->next is drawn. */
    x_set_glyph_string_clipping_exactly (s, s);
  else
    x_set_glyph_string_clipping (s);

  switch (s->first_glyph->type)
    {
    case IMAGE_GLYPH:
      x_draw_image_glyph_string (s);
      break;

    case XWIDGET_GLYPH:
      x_draw_xwidget_glyph_string (s);
      break;

    case STRETCH_GLYPH:
      x_draw_stretch_glyph_string (s);
      break;

    case CHAR_GLYPH:
      if (s->for_overlaps)
        s->background_filled_p = true;
      else
        x_draw_glyph_string_background (s, false);
      x_draw_glyph_string_foreground (s);
      break;

    case COMPOSITE_GLYPH:
      if (s->for_overlaps || (s->cmp_from > 0
                              && ! s->first_glyph->u.cmp.automatic))
        s->background_filled_p = true;
      else
        x_draw_glyph_string_background (s, true);
      x_draw_composite_glyph_string_foreground (s);
      break;

    case GLYPHLESS_GLYPH:
      if (s->for_overlaps)
        s->background_filled_p = true;
      else
        x_draw_glyph_string_background (s, true);
      x_draw_glyphless_glyph_string_foreground (s);
      break;

    default:
      emacs_abort ();
    }

  if (!s->for_overlaps)
    {
      /* Draw underline.  */
      if (s->face->underline_p)
        {
          if (s->face->underline_type == FACE_UNDER_WAVE)
            {
              if (s->face->underline_defaulted_p)
                x_draw_underwave (s);
              else
                {
                  XGCValues xgcv;
                  XGetGCValues (s->display, s->gc, GCForeground, &xgcv);
                  XSetForeground (s->display, s->gc, s->face->underline_color);
                  x_draw_underwave (s);
                  XSetForeground (s->display, s->gc, xgcv.foreground);
                }
            }
          else if (s->face->underline_type == FACE_UNDER_LINE)
            {
              unsigned long thickness, position;
              int y;

              if (s->prev && s->prev->face->underline_p
                  && s->prev->face->underline_type == FACE_UNDER_LINE)
                {
                  /* We use the same underline style as the previous one.  */
                  thickness = s->prev->underline_thickness;
                  position = s->prev->underline_position;
                }
              else
                {
                  struct font *font = font_for_underline_metrics (s);

                  /* Get the underline thickness.  Default is 1 pixel.  */
                  if (font && font->underline_thickness > 0)
                    thickness = font->underline_thickness;
                  else
                    thickness = 1;
                  if (x_underline_at_descent_line)
                    position = (s->height - thickness) - (s->ybase - s->y);
                  else
                    {
                      /* Get the underline position.  This is the recommended
                         vertical offset in pixels from the baseline to the top of
                         the underline.  This is a signed value according to the
                         specs, and its default is

                         ROUND ((maximum descent) / 2), with
                         ROUND(x) = floor (x + 0.5)  */

                      if (x_use_underline_position_properties
                          && font && font->underline_position >= 0)
                        position = font->underline_position;
                      else if (font)
                        position = (font->descent + 1) / 2;
                      else
                        position = underline_minimum_offset;
                    }
                  position = max (position, underline_minimum_offset);
                }
              /* Check the sanity of thickness and position.  We should
                 avoid drawing underline out of the current line area.  */
              if (s->y + s->height <= s->ybase + position)
                position = (s->height - 1) - (s->ybase - s->y);
              if (s->y + s->height < s->ybase + position + thickness)
                thickness = (s->y + s->height) - (s->ybase + position);
              s->underline_thickness = thickness;
              s->underline_position = position;
              y = s->ybase + position;
              if (s->face->underline_defaulted_p)
                x_fill_rectangle (s->f, s->gc,
                                s->x, y, s->width, thickness);
              else
                {
                  XGCValues xgcv;
                  XGetGCValues (s->display, s->gc, GCForeground, &xgcv);
                  XSetForeground (s->display, s->gc, s->face->underline_color);
                  x_fill_rectangle (s->f, s->gc,
                                  s->x, y, s->width, thickness);
                  XSetForeground (s->display, s->gc, xgcv.foreground);
                }
            }
        }
      /* Draw overline.  */
      if (s->face->overline_p)
        {
          unsigned long dy = 0, h = 1;

          if (s->face->overline_color_defaulted_p)
            x_fill_rectangle (s->f, s->gc, s->x, s->y + dy,
                            s->width, h);
          else
            {
              XGCValues xgcv;
              XGetGCValues (s->display, s->gc, GCForeground, &xgcv);
              XSetForeground (s->display, s->gc, s->face->overline_color);
              x_fill_rectangle (s->f, s->gc, s->x, s->y + dy,
                              s->width, h);
              XSetForeground (s->display, s->gc, xgcv.foreground);
            }
        }

      /* Draw strike-through.  */
      if (s->face->strike_through_p)
        {
          /* Y-coordinate and height of the glyph string's first
             glyph.  We cannot use s->y and s->height because those
             could be larger if there are taller display elements
             (e.g., characters displayed with a larger font) in the
             same glyph row.  */
          int glyph_y = s->ybase - s->first_glyph->ascent;
          int glyph_height = s->first_glyph->ascent + s->first_glyph->descent;
          /* Strike-through width and offset from the glyph string's
             top edge.  */
          unsigned long h = 1;
          unsigned long dy = (glyph_height - h) / 2;

          if (s->face->strike_through_color_defaulted_p)
            x_fill_rectangle (s->f, s->gc, s->x, glyph_y + dy,
                            s->width, h);
          else
            {
              XGCValues xgcv;
              XGetGCValues (s->display, s->gc, GCForeground, &xgcv);
              XSetForeground (s->display, s->gc, s->face->strike_through_color);
              x_fill_rectangle (s->f, s->gc, s->x, glyph_y + dy,
                              s->width, h);
              XSetForeground (s->display, s->gc, xgcv.foreground);
            }
        }

      /* Draw relief if not yet drawn.  */
      if (!relief_drawn_p && s->face->box != FACE_NO_BOX)
        x_draw_glyph_string_box (s);

      if (s->prev)
        {
          struct glyph_string *prev;

          for (prev = s->prev; prev; prev = prev->prev)
            if (prev->hl != s->hl
                && prev->x + prev->width + prev->right_overhang > s->x)
              {
                /* As prev was drawn while clipped to its own area, we
                   must draw the right_overhang part using s->hl now.  */
                enum draw_glyphs_face save = prev->hl;

                prev->hl = s->hl;
                x_set_glyph_string_gc (prev);
                x_set_glyph_string_clipping_exactly (s, prev);
                if (prev->first_glyph->type == CHAR_GLYPH)
                  x_draw_glyph_string_foreground (prev);
                else
                  x_draw_composite_glyph_string_foreground (prev);
                x_reset_clip_rectangles (prev->f, prev->gc);
                prev->hl = save;
                prev->num_clips = 0;
              }
        }

      if (s->next)
        {
          struct glyph_string *next;

          for (next = s->next; next; next = next->next)
            if (next->hl != s->hl
                && next->x - next->left_overhang < s->x + s->width)
              {
                /* As next will be drawn while clipped to its own area,
                   we must draw the left_overhang part using s->hl now.  */
                enum draw_glyphs_face save = next->hl;

                next->hl = s->hl;
                x_set_glyph_string_gc (next);
                x_set_glyph_string_clipping_exactly (s, next);
                if (next->first_glyph->type == CHAR_GLYPH)
                  x_draw_glyph_string_foreground (next);
                else
                  x_draw_composite_glyph_string_foreground (next);
                x_reset_clip_rectangles (next->f, next->gc);
                next->hl = save;
                next->num_clips = 0;
                next->clip_head = s->next;
              }
        }
    }

  /* Reset clipping.  */
  x_reset_clip_rectangles (s->f, s->gc);
  s->num_clips = 0;
}

/* Shift display to make room for inserted glyphs.   */

static void
x_shift_glyphs_for_insert (struct frame *f, int x, int y, int width, int height, int shift_by)
{
/* Never called on a GUI frame, see
   http://lists.gnu.org/archive/html/emacs-devel/2015-05/msg00456.html
*/
  XCopyArea (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f), FRAME_X_DRAWABLE (f),
             f->output_data.x->normal_gc,
             x, y, width, height,
             x + shift_by, y);
}

/* Delete N glyphs at the nominal cursor position.  Not implemented
   for X frames.  */

static void
x_delete_glyphs (struct frame *f, register int n)
{
  emacs_abort ();
}


/* Like XClearArea, but check that WIDTH and HEIGHT are reasonable.
   If they are <= 0, this is probably an error.  */

static ATTRIBUTE_UNUSED void
x_clear_area1 (Display *dpy, Window window,
               int x, int y, int width, int height, int exposures)
{
  eassert (width > 0 && height > 0);
  XClearArea (dpy, window, x, y, width, height, exposures);
}

void
x_clear_area (struct frame *f, int x, int y, int width, int height)
{
#ifdef USE_CAIRO
  cairo_t *cr;

  eassert (width > 0 && height > 0);

  cr = x_begin_cr_clip (f, NULL);
  x_set_cr_source_with_gc_background (f, f->output_data.x->normal_gc);
  cairo_rectangle (cr, x, y, width, height);
  cairo_fill (cr);
  x_end_cr_clip (f);
#else
  if (FRAME_X_DOUBLE_BUFFERED_P (f))
    XFillRectangle (FRAME_X_DISPLAY (f),
                    FRAME_X_DRAWABLE (f),
                    f->output_data.x->reverse_gc,
                    x, y, width, height);
  else
    x_clear_area1 (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
                   x, y, width, height, False);
#endif
}


/* Clear an entire frame.  */

static void
x_clear_frame (struct frame *f)
{
  /* Clearing the frame will erase any cursor, so mark them all as no
     longer visible.  */
  mark_window_cursors_off (XWINDOW (FRAME_ROOT_WINDOW (f)));

  block_input ();

  font_drop_xrender_surfaces (f);
  x_clear_window (f);

  /* We have to clear the scroll bars.  If we have changed colors or
     something like that, then they should be notified.  */
  x_scroll_bar_clear (f);

  XFlush (FRAME_X_DISPLAY (f));

  unblock_input ();
}

/* RIF: Show hourglass cursor on frame F.  */

static void
x_show_hourglass (struct frame *f)
{
  Display *dpy = FRAME_X_DISPLAY (f);

  if (dpy)
    {
      struct x_output *x = FRAME_X_OUTPUT (f);
#ifdef USE_X_TOOLKIT
      if (x->widget)
#else
      if (FRAME_OUTER_WINDOW (f))
#endif
       {
         x->hourglass_p = true;

         if (!x->hourglass_window)
           {
             unsigned long mask = CWCursor;
             XSetWindowAttributes attrs;
#ifdef USE_GTK
             Window parent = FRAME_X_WINDOW (f);
#else
             Window parent = FRAME_OUTER_WINDOW (f);
#endif
             attrs.cursor = x->hourglass_cursor;

             x->hourglass_window = XCreateWindow
               (dpy, parent, 0, 0, 32000, 32000, 0, 0,
                InputOnly, CopyFromParent, mask, &attrs);
           }

         XMapRaised (dpy, x->hourglass_window);
         XFlush (dpy);
       }
    }
}

/* RIF: Cancel hourglass cursor on frame F.  */

static void
x_hide_hourglass (struct frame *f)
{
  struct x_output *x = FRAME_X_OUTPUT (f);

  /* Watch out for newly created frames.  */
  if (x->hourglass_window)
    {
      XUnmapWindow (FRAME_X_DISPLAY (f), x->hourglass_window);
      /* Sync here because XTread_socket looks at the
         hourglass_p flag that is reset to zero below.  */
      XSync (FRAME_X_DISPLAY (f), False);
      x->hourglass_p = false;
    }
}

/* Invert the middle quarter of the frame for .15 sec.  */

static void
XTflash (struct frame *f)
{
  block_input ();

  {
#ifdef USE_GTK
    /* Use Gdk routines to draw.  This way, we won't draw over scroll bars
       when the scroll bars and the edit widget share the same X window.  */
    GdkWindow *window = gtk_widget_get_window (FRAME_GTK_WIDGET (f));
#ifdef HAVE_GTK3
    cairo_t *cr = gdk_cairo_create (window);
    cairo_set_source_rgb (cr, 1, 1, 1);
    cairo_set_operator (cr, CAIRO_OPERATOR_DIFFERENCE);
#define XFillRectangle(d, win, gc, x, y, w, h) \
    do {                                       \
      cairo_rectangle (cr, x, y, w, h);        \
      cairo_fill (cr);                         \
    }                                          \
    while (false)
#else /* ! HAVE_GTK3 */
    GdkGCValues vals;
    GdkGC *gc;
    vals.foreground.pixel = (FRAME_FOREGROUND_PIXEL (f)
                             ^ FRAME_BACKGROUND_PIXEL (f));
    vals.function = GDK_XOR;
    gc = gdk_gc_new_with_values (window,
                                 &vals, GDK_GC_FUNCTION | GDK_GC_FOREGROUND);
#define XFillRectangle(d, win, gc, x, y, w, h) \
    gdk_draw_rectangle (window, gc, true, x, y, w, h)
#endif /* ! HAVE_GTK3 */
#else /* ! USE_GTK */
    GC gc;

    /* Create a GC that will use the GXxor function to flip foreground
       pixels into background pixels.  */
    {
      XGCValues values;

      values.function = GXxor;
      values.foreground = (FRAME_FOREGROUND_PIXEL (f)
                           ^ FRAME_BACKGROUND_PIXEL (f));

      gc = XCreateGC (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
                      GCFunction | GCForeground, &values);
    }
#endif
    {
      /* Get the height not including a menu bar widget.  */
      int height = FRAME_PIXEL_HEIGHT (f);
      /* Height of each line to flash.  */
      int flash_height = FRAME_LINE_HEIGHT (f);
      /* These will be the left and right margins of the rectangles.  */
      int flash_left = FRAME_INTERNAL_BORDER_WIDTH (f);
      int flash_right = FRAME_PIXEL_WIDTH (f) - FRAME_INTERNAL_BORDER_WIDTH (f);
      int width = flash_right - flash_left;

      /* If window is tall, flash top and bottom line.  */
      if (height > 3 * FRAME_LINE_HEIGHT (f))
        {
          XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
                          flash_left,
                          (FRAME_INTERNAL_BORDER_WIDTH (f)
                           + FRAME_TOP_MARGIN_HEIGHT (f)),
                          width, flash_height);
          XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
                          flash_left,
                          (height - flash_height
                           - FRAME_INTERNAL_BORDER_WIDTH (f)),
                          width, flash_height);

        }
      else
        /* If it is short, flash it all.  */
        XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
                        flash_left, FRAME_INTERNAL_BORDER_WIDTH (f),
                        width, height - 2 * FRAME_INTERNAL_BORDER_WIDTH (f));

      x_flush (f);

      {
        struct timespec delay = make_timespec (0, 150 * 1000 * 1000);
        struct timespec wakeup = timespec_add (current_timespec (), delay);

        /* Keep waiting until past the time wakeup or any input gets
           available.  */
        while (! detect_input_pending ())
          {
            struct timespec current = current_timespec ();
            struct timespec timeout;

            /* Break if result would not be positive.  */
            if (timespec_cmp (wakeup, current) <= 0)
              break;

            /* How long `select' should wait.  */
            timeout = make_timespec (0, 10 * 1000 * 1000);

            /* Try to wait that long--but we might wake up sooner.  */
            pselect (0, NULL, NULL, NULL, &timeout, NULL);
          }
      }

      /* If window is tall, flash top and bottom line.  */
      if (height > 3 * FRAME_LINE_HEIGHT (f))
        {
          XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
                          flash_left,
                          (FRAME_INTERNAL_BORDER_WIDTH (f)
                           + FRAME_TOP_MARGIN_HEIGHT (f)),
                          width, flash_height);
          XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
                          flash_left,
                          (height - flash_height
                           - FRAME_INTERNAL_BORDER_WIDTH (f)),
                          width, flash_height);
        }
      else
        /* If it is short, flash it all.  */
        XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
                        flash_left, FRAME_INTERNAL_BORDER_WIDTH (f),
                        width, height - 2 * FRAME_INTERNAL_BORDER_WIDTH (f));

#ifdef USE_GTK
#ifdef HAVE_GTK3
      cairo_destroy (cr);
#else
      g_object_unref (G_OBJECT (gc));
#endif
#undef XFillRectangle
#else
      XFreeGC (FRAME_X_DISPLAY (f), gc);
#endif
      x_flush (f);
    }
  }

  unblock_input ();
}


static void
XTtoggle_invisible_pointer (struct frame *f, bool invisible)
{
  block_input ();
  FRAME_DISPLAY_INFO (f)->toggle_visible_pointer (f, invisible);
  unblock_input ();
}


/* Make audible bell.  */

static void
XTring_bell (struct frame *f)
{
  if (FRAME_X_DISPLAY (f))
    {
      if (visible_bell)
        XTflash (f);
      else
        {
          block_input ();
#ifdef HAVE_XKB
          XkbBell (FRAME_X_DISPLAY (f), None, 0, None);
#else
          XBell (FRAME_X_DISPLAY (f), 0);
#endif
          XFlush (FRAME_X_DISPLAY (f));
          unblock_input ();
        }
    }
}

/***********************************************************************
                              Line Dance
 ***********************************************************************/

/* Perform an insert-lines or delete-lines operation, inserting N
   lines or deleting -N lines at vertical position VPOS.  */

static void
x_ins_del_lines (struct frame *f, int vpos, int n)
{
  emacs_abort ();
}


/* Scroll part of the display as described by RUN.  */

static void
x_scroll_run (struct window *w, struct run *run)
{
  struct frame *f = XFRAME (w->frame);
  int x, y, width, height, from_y, to_y, bottom_y;

  /* Get frame-relative bounding box of the text display area of W,
     without mode lines.  Include in this box the left and right
     fringe of W.  */
  window_box (w, ANY_AREA, &x, &y, &width, &height);

  from_y = WINDOW_TO_FRAME_PIXEL_Y (w, run->current_y);
  to_y = WINDOW_TO_FRAME_PIXEL_Y (w, run->desired_y);
  bottom_y = y + height;

  if (to_y < from_y)
    {
      /* Scrolling up.  Make sure we don't copy part of the mode
         line at the bottom.  */
      if (from_y + run->height > bottom_y)
        height = bottom_y - from_y;
      else
        height = run->height;
    }
  else
    {
      /* Scrolling down.  Make sure we don't copy over the mode line.
         at the bottom.  */
      if (to_y + run->height > bottom_y)
        height = bottom_y - to_y;
      else
        height = run->height;
    }

  block_input ();

  /* Cursor off.  Will be switched on again in x_update_window_end.  */
  x_clear_cursor (w);

#ifdef USE_CAIRO
  SET_FRAME_GARBAGED (f);
#else
  XCopyArea (FRAME_X_DISPLAY (f),
             FRAME_X_DRAWABLE (f), FRAME_X_DRAWABLE (f),
             f->output_data.x->normal_gc,
             x, from_y,
             width, height,
             x, to_y);
#endif

  unblock_input ();
}


\f
/***********************************************************************
                           Exposure Events
 ***********************************************************************/

\f
static void
frame_highlight (struct frame *f)
{
  /* We used to only do this if Vx_no_window_manager was non-nil, but
     the ICCCM (section 4.1.6) says that the window's border pixmap
     and border pixel are window attributes which are "private to the
     client", so we can always change it to whatever we want.  */
  block_input ();
  /* I recently started to get errors in this XSetWindowBorder, depending on
     the window-manager in use, tho something more is at play since I've been
     using that same window-manager binary for ever.  Let's not crash just
     because of this (bug#9310).  */
  x_catch_errors (FRAME_X_DISPLAY (f));
  XSetWindowBorder (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
                    f->output_data.x->border_pixel);
  x_uncatch_errors ();
  unblock_input ();
  x_update_cursor (f, true);
  x_set_frame_alpha (f);
}

static void
frame_unhighlight (struct frame *f)
{
  /* We used to only do this if Vx_no_window_manager was non-nil, but
     the ICCCM (section 4.1.6) says that the window's border pixmap
     and border pixel are window attributes which are "private to the
     client", so we can always change it to whatever we want.  */
  block_input ();
  /* Same as above for XSetWindowBorder (bug#9310).  */
  x_catch_errors (FRAME_X_DISPLAY (f));
  XSetWindowBorderPixmap (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
                          f->output_data.x->border_tile);
  x_uncatch_errors ();
  unblock_input ();
  x_update_cursor (f, true);
  x_set_frame_alpha (f);
}

/* The focus has changed.  Update the frames as necessary to reflect
   the new situation.  Note that we can't change the selected frame
   here, because the Lisp code we are interrupting might become confused.
   Each event gets marked with the frame in which it occurred, so the
   Lisp code can tell when the switch took place by examining the events.  */

static void
x_new_focus_frame (struct x_display_info *dpyinfo, struct frame *frame)
{
  struct frame *old_focus = dpyinfo->x_focus_frame;

  if (frame != dpyinfo->x_focus_frame)
    {
      /* Set this before calling other routines, so that they see
         the correct value of x_focus_frame.  */
      dpyinfo->x_focus_frame = frame;

      if (old_focus && old_focus->auto_lower)
        x_lower_frame (old_focus);

      if (dpyinfo->x_focus_frame && dpyinfo->x_focus_frame->auto_raise)
        dpyinfo->x_pending_autoraise_frame = dpyinfo->x_focus_frame;
      else
        dpyinfo->x_pending_autoraise_frame = NULL;
    }

  x_frame_rehighlight (dpyinfo);
}

/* Handle FocusIn and FocusOut state changes for FRAME.
   If FRAME has focus and there exists more than one frame, puts
   a FOCUS_IN_EVENT into *BUFP.  */

static void
x_focus_changed (int type, int state, struct x_display_info *dpyinfo, struct frame *frame, struct input_event *bufp)
{
  if (type == FocusIn)
    {
      if (dpyinfo->x_focus_event_frame != frame)
        {
          x_new_focus_frame (dpyinfo, frame);
          dpyinfo->x_focus_event_frame = frame;

          /* Don't stop displaying the initial startup message
             for a switch-frame event we don't need.  */
          /* When run as a daemon, Vterminal_frame is always NIL.  */
          bufp->arg = (((NILP (Vterminal_frame)
                         || ! FRAME_X_P (XFRAME (Vterminal_frame))
                         || EQ (Fdaemonp (), Qt))
                        && CONSP (Vframe_list)
                        && !NILP (XCDR (Vframe_list)))
                       ? Qt : Qnil);
          bufp->kind = FOCUS_IN_EVENT;
          XSETFRAME (bufp->frame_or_window, frame);
        }

      frame->output_data.x->focus_state |= state;

#ifdef HAVE_X_I18N
      if (FRAME_XIC (frame))
        XSetICFocus (FRAME_XIC (frame));
#endif
    }
  else if (type == FocusOut)
    {
      frame->output_data.x->focus_state &= ~state;

      if (dpyinfo->x_focus_event_frame == frame)
        {
          dpyinfo->x_focus_event_frame = 0;
          x_new_focus_frame (dpyinfo, 0);

          bufp->kind = FOCUS_OUT_EVENT;
          XSETFRAME (bufp->frame_or_window, frame);
        }

#ifdef HAVE_X_I18N
      if (FRAME_XIC (frame))
        XUnsetICFocus (FRAME_XIC (frame));
#endif
      if (frame->pointer_invisible)
        XTtoggle_invisible_pointer (frame, false);
    }
}

/* Return the Emacs frame-object corresponding to an X window.
   It could be the frame's main window or an icon window.  */

static struct frame *
x_window_to_frame (struct x_display_info *dpyinfo, int wdesc)
{
  Lisp_Object tail, frame;
  struct frame *f;

  if (wdesc == None)
    return NULL;

  FOR_EACH_FRAME (tail, frame)
    {
      f = XFRAME (frame);
      if (!FRAME_X_P (f) || FRAME_DISPLAY_INFO (f) != dpyinfo)
        continue;
      if (f->output_data.x->hourglass_window == wdesc)
        return f;
#ifdef USE_X_TOOLKIT
      if ((f->output_data.x->edit_widget
           && XtWindow (f->output_data.x->edit_widget) == wdesc)
          /* A tooltip frame?  */
          || (!f->output_data.x->edit_widget
              && FRAME_X_WINDOW (f) == wdesc)
          || f->output_data.x->icon_desc == wdesc)
        return f;
#else /* not USE_X_TOOLKIT */
#ifdef USE_GTK
      if (f->output_data.x->edit_widget)
      {
        GtkWidget *gwdesc = xg_win_to_widget (dpyinfo->display, wdesc);
        struct x_output *x = f->output_data.x;
        if (gwdesc != 0 && gwdesc == x->edit_widget)
          return f;
      }
#endif /* USE_GTK */
      if (FRAME_X_WINDOW (f) == wdesc
          || f->output_data.x->icon_desc == wdesc)
        return f;
#endif /* not USE_X_TOOLKIT */
    }
  return 0;
}

#if defined (USE_X_TOOLKIT) || defined (USE_GTK)

/* Like x_window_to_frame but also compares the window with the widget's
   windows.  */

static struct frame *
x_any_window_to_frame (struct x_display_info *dpyinfo, int wdesc)
{
  Lisp_Object tail, frame;
  struct frame *f, *found = NULL;
  struct x_output *x;

  if (wdesc == None)
    return NULL;

  FOR_EACH_FRAME (tail, frame)
    {
      if (found)
        break;
      f = XFRAME (frame);
      if (FRAME_X_P (f) && FRAME_DISPLAY_INFO (f) == dpyinfo)
        {
          /* This frame matches if the window is any of its widgets.  */
          x = f->output_data.x;
          if (x->hourglass_window == wdesc)
            found = f;
          else if (x->widget)
            {
#ifdef USE_GTK
              GtkWidget *gwdesc = xg_win_to_widget (dpyinfo->display, wdesc);
              if (gwdesc != 0
                  && gtk_widget_get_toplevel (gwdesc) == x->widget)
                found = f;
#else
              if (wdesc == XtWindow (x->widget)
                  || wdesc == XtWindow (x->column_widget)
                  || wdesc == XtWindow (x->edit_widget))
                found = f;
              /* Match if the window is this frame's menubar.  */
              else if (lw_window_is_in_menubar (wdesc, x->menubar_widget))
                found = f;
#endif
            }
          else if (FRAME_X_WINDOW (f) == wdesc)
            /* A tooltip frame.  */
            found = f;
        }
    }

  return found;
}

/* Likewise, but consider only the menu bar widget.  */

static struct frame *
x_menubar_window_to_frame (struct x_display_info *dpyinfo,
                           const XEvent *event)
{
  Window wdesc = event->xany.window;
  Lisp_Object tail, frame;
  struct frame *f;
  struct x_output *x;

  if (wdesc == None)
    return NULL;

  FOR_EACH_FRAME (tail, frame)
    {
      f = XFRAME (frame);
      if (!FRAME_X_P (f) || FRAME_DISPLAY_INFO (f) != dpyinfo)
        continue;
      x = f->output_data.x;
#ifdef USE_GTK
      if (x->menubar_widget && xg_event_is_for_menubar (f, event))
        return f;
#else
      /* Match if the window is this frame's menubar.  */
      if (x->menubar_widget
          && lw_window_is_in_menubar (wdesc, x->menubar_widget))
        return f;
#endif
    }
  return 0;
}

/* Return the frame whose principal (outermost) window is WDESC.
   If WDESC is some other (smaller) window, we return 0.  */

struct frame *
x_top_window_to_frame (struct x_display_info *dpyinfo, int wdesc)
{
  Lisp_Object tail, frame;
  struct frame *f;
  struct x_output *x;

  if (wdesc == None)
    return NULL;

  FOR_EACH_FRAME (tail, frame)
    {
      f = XFRAME (frame);
      if (!FRAME_X_P (f) || FRAME_DISPLAY_INFO (f) != dpyinfo)
        continue;
      x = f->output_data.x;

      if (x->widget)
        {
          /* This frame matches if the window is its topmost widget.  */
#ifdef USE_GTK
          GtkWidget *gwdesc = xg_win_to_widget (dpyinfo->display, wdesc);
          if (gwdesc == x->widget)
            return f;
#else
          if (wdesc == XtWindow (x->widget))
            return f;
#endif
        }
      else if (FRAME_X_WINDOW (f) == wdesc)
        /* Tooltip frame.  */
        return f;
    }
  return 0;
}

#else /* !USE_X_TOOLKIT && !USE_GTK */

#define x_any_window_to_frame(d, i) x_window_to_frame (d, i)
#define x_top_window_to_frame(d, i) x_window_to_frame (d, i)

#endif /* USE_X_TOOLKIT || USE_GTK */

/* The focus may have changed.  Figure out if it is a real focus change,
   by checking both FocusIn/Out and Enter/LeaveNotify events.

   Returns FOCUS_IN_EVENT event in *BUFP. */

static void
x_detect_focus_change (struct x_display_info *dpyinfo, struct frame *frame,
                       const XEvent *event, struct input_event *bufp)
{
  if (!frame)
    return;

  switch (event->type)
    {
    case EnterNotify:
    case LeaveNotify:
      {
        struct frame *focus_frame = dpyinfo->x_focus_event_frame;
        int focus_state
          = focus_frame ? focus_frame->output_data.x->focus_state : 0;

        if (event->xcrossing.detail != NotifyInferior
            && event->xcrossing.focus
            && ! (focus_state & FOCUS_EXPLICIT))
          x_focus_changed ((event->type == EnterNotify ? FocusIn : FocusOut),
                           FOCUS_IMPLICIT,
                           dpyinfo, frame, bufp);
      }
      break;

    case FocusIn:
    case FocusOut:
      x_focus_changed (event->type,
                       (event->xfocus.detail == NotifyPointer ?
                        FOCUS_IMPLICIT : FOCUS_EXPLICIT),
                       dpyinfo, frame, bufp);
      break;

    case ClientMessage:
      if (event->xclient.message_type == dpyinfo->Xatom_XEMBED)
        {
          enum xembed_message msg = event->xclient.data.l[1];
          x_focus_changed ((msg == XEMBED_FOCUS_IN ? FocusIn : FocusOut),
                           FOCUS_EXPLICIT, dpyinfo, frame, bufp);
        }
      break;
    }
}


#if !defined USE_X_TOOLKIT && !defined USE_GTK
/* Handle an event saying the mouse has moved out of an Emacs frame.  */

void
x_mouse_leave (struct x_display_info *dpyinfo)
{
  x_new_focus_frame (dpyinfo, dpyinfo->x_focus_event_frame);
}
#endif

/* The focus has changed, or we have redirected a frame's focus to
   another frame (this happens when a frame uses a surrogate
   mini-buffer frame).  Shift the highlight as appropriate.

   The FRAME argument doesn't necessarily have anything to do with which
   frame is being highlighted or un-highlighted; we only use it to find
   the appropriate X display info.  */

static void
XTframe_rehighlight (struct frame *frame)
{
  x_frame_rehighlight (FRAME_DISPLAY_INFO (frame));
}

static void
x_frame_rehighlight (struct x_display_info *dpyinfo)
{
  struct frame *old_highlight = dpyinfo->x_highlight_frame;

  if (dpyinfo->x_focus_frame)
    {
      dpyinfo->x_highlight_frame
        = ((FRAMEP (FRAME_FOCUS_FRAME (dpyinfo->x_focus_frame)))
           ? XFRAME (FRAME_FOCUS_FRAME (dpyinfo->x_focus_frame))
           : dpyinfo->x_focus_frame);
      if (! FRAME_LIVE_P (dpyinfo->x_highlight_frame))
        {
          fset_focus_frame (dpyinfo->x_focus_frame, Qnil);
          dpyinfo->x_highlight_frame = dpyinfo->x_focus_frame;
        }
    }
  else
    dpyinfo->x_highlight_frame = 0;

  if (dpyinfo->x_highlight_frame != old_highlight)
    {
      if (old_highlight)
        frame_unhighlight (old_highlight);
      if (dpyinfo->x_highlight_frame)
        frame_highlight (dpyinfo->x_highlight_frame);
    }
}


\f
/* Keyboard processing - modifier keys, vendor-specific keysyms, etc.  */

/* Initialize mode_switch_bit and modifier_meaning.  */
static void
x_find_modifier_meanings (struct x_display_info *dpyinfo)
{
  int min_code, max_code;
  KeySym *syms;
  int syms_per_code;
  XModifierKeymap *mods;

  dpyinfo->meta_mod_mask = 0;
  dpyinfo->shift_lock_mask = 0;
  dpyinfo->alt_mod_mask = 0;
  dpyinfo->super_mod_mask = 0;
  dpyinfo->hyper_mod_mask = 0;

  XDisplayKeycodes (dpyinfo->display, &min_code, &max_code);

  syms = XGetKeyboardMapping (dpyinfo->display,
                              min_code, max_code - min_code + 1,
                              &syms_per_code);
  mods = XGetModifierMapping (dpyinfo->display);

  /* Scan the modifier table to see which modifier bits the Meta and
     Alt keysyms are on.  */
  {
    int row, col;       /* The row and column in the modifier table.  */
    bool found_alt_or_meta;

    for (row = 3; row < 8; row++)
    {
      found_alt_or_meta = false;
      for (col = 0; col < mods->max_keypermod; col++)
        {
          KeyCode code = mods->modifiermap[(row * mods->max_keypermod) + col];

          /* Zeroes are used for filler.  Skip them.  */
          if (code == 0)
            continue;

          /* Are any of this keycode's keysyms a meta key?  */
          {
            int code_col;

            for (code_col = 0; code_col < syms_per_code; code_col++)
              {
                int sym = syms[((code - min_code) * syms_per_code) + code_col];

                switch (sym)
                  {
                  case XK_Meta_L:
                  case XK_Meta_R:
                    found_alt_or_meta = true;
                    dpyinfo->meta_mod_mask |= (1 << row);
                    break;

                  case XK_Alt_L:
                  case XK_Alt_R:
                    found_alt_or_meta = true;
                    dpyinfo->alt_mod_mask |= (1 << row);
                    break;

                  case XK_Hyper_L:
                  case XK_Hyper_R:
                    if (!found_alt_or_meta)
                      dpyinfo->hyper_mod_mask |= (1 << row);
                    code_col = syms_per_code;
                    col = mods->max_keypermod;
                    break;

                  case XK_Super_L:
                  case XK_Super_R:
                    if (!found_alt_or_meta)
                      dpyinfo->super_mod_mask |= (1 << row);
                    code_col = syms_per_code;
                    col = mods->max_keypermod;
                    break;

                  case XK_Shift_Lock:
                    /* Ignore this if it's not on the lock modifier.  */
                    if (!found_alt_or_meta && ((1 << row) == LockMask))
                      dpyinfo->shift_lock_mask = LockMask;
                    code_col = syms_per_code;
                    col = mods->max_keypermod;
                    break;
                  }
              }
          }
        }
    }
  }

  /* If we couldn't find any meta keys, accept any alt keys as meta keys.  */
  if (! dpyinfo->meta_mod_mask)
    {
      dpyinfo->meta_mod_mask = dpyinfo->alt_mod_mask;
      dpyinfo->alt_mod_mask = 0;
    }

  /* If some keys are both alt and meta,
     make them just meta, not alt.  */
  if (dpyinfo->alt_mod_mask & dpyinfo->meta_mod_mask)
    {
      dpyinfo->alt_mod_mask &= ~dpyinfo->meta_mod_mask;
    }

  XFree (syms);
  XFreeModifiermap (mods);
}

/* Convert between the modifier bits X uses and the modifier bits
   Emacs uses.  */

int
x_x_to_emacs_modifiers (struct x_display_info *dpyinfo, int state)
{
  int mod_ctrl = ctrl_modifier;
  int mod_meta = meta_modifier;
  int mod_alt  = alt_modifier;
  int mod_hyper = hyper_modifier;
  int mod_super = super_modifier;
  Lisp_Object tem;

  tem = Fget (Vx_ctrl_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_ctrl = XINT (tem) & INT_MAX;
  tem = Fget (Vx_alt_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_alt = XINT (tem) & INT_MAX;
  tem = Fget (Vx_meta_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_meta = XINT (tem) & INT_MAX;
  tem = Fget (Vx_hyper_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_hyper = XINT (tem) & INT_MAX;
  tem = Fget (Vx_super_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_super = XINT (tem) & INT_MAX;

  return (  ((state & (ShiftMask | dpyinfo->shift_lock_mask)) ? shift_modifier : 0)
            | ((state & ControlMask)                    ? mod_ctrl      : 0)
            | ((state & dpyinfo->meta_mod_mask)         ? mod_meta      : 0)
            | ((state & dpyinfo->alt_mod_mask)          ? mod_alt       : 0)
            | ((state & dpyinfo->super_mod_mask)        ? mod_super     : 0)
            | ((state & dpyinfo->hyper_mod_mask)        ? mod_hyper     : 0));
}

static int
x_emacs_to_x_modifiers (struct x_display_info *dpyinfo, EMACS_INT state)
{
  EMACS_INT mod_ctrl = ctrl_modifier;
  EMACS_INT mod_meta = meta_modifier;
  EMACS_INT mod_alt  = alt_modifier;
  EMACS_INT mod_hyper = hyper_modifier;
  EMACS_INT mod_super = super_modifier;

  Lisp_Object tem;

  tem = Fget (Vx_ctrl_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_ctrl = XINT (tem);
  tem = Fget (Vx_alt_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_alt = XINT (tem);
  tem = Fget (Vx_meta_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_meta = XINT (tem);
  tem = Fget (Vx_hyper_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_hyper = XINT (tem);
  tem = Fget (Vx_super_keysym, Qmodifier_value);
  if (INTEGERP (tem)) mod_super = XINT (tem);


  return (  ((state & mod_alt)          ? dpyinfo->alt_mod_mask   : 0)
            | ((state & mod_super)      ? dpyinfo->super_mod_mask : 0)
            | ((state & mod_hyper)      ? dpyinfo->hyper_mod_mask : 0)
            | ((state & shift_modifier) ? ShiftMask        : 0)
            | ((state & mod_ctrl)       ? ControlMask      : 0)
            | ((state & mod_meta)       ? dpyinfo->meta_mod_mask  : 0));
}

/* Convert a keysym to its name.  */

char *
x_get_keysym_name (int keysym)
{
  char *value;

  block_input ();
  value = XKeysymToString (keysym);
  unblock_input ();

  return value;
}

/* Mouse clicks and mouse movement.  Rah.

   Formerly, we used PointerMotionHintMask (in standard_event_mask)
   so that we would have to call XQueryPointer after each MotionNotify
   event to ask for another such event.  However, this made mouse tracking
   slow, and there was a bug that made it eventually stop.

   Simply asking for MotionNotify all the time seems to work better.

   In order to avoid asking for motion events and then throwing most
   of them away or busy-polling the server for mouse positions, we ask
   the server for pointer motion hints.  This means that we get only
   one event per group of mouse movements.  "Groups" are delimited by
   other kinds of events (focus changes and button clicks, for
   example), or by XQueryPointer calls; when one of these happens, we
   get another MotionNotify event the next time the mouse moves.  This
   is at least as efficient as getting motion events when mouse
   tracking is on, and I suspect only negligibly worse when tracking
   is off.  */

/* Prepare a mouse-event in *RESULT for placement in the input queue.

   If the event is a button press, then note that we have grabbed
   the mouse.  */

static Lisp_Object
construct_mouse_click (struct input_event *result,
                       const XButtonEvent *event,
                       struct frame *f)
{
  /* Make the event type NO_EVENT; we'll change that when we decide
     otherwise.  */
  result->kind = MOUSE_CLICK_EVENT;
  result->code = event->button - Button1;
  result->timestamp = event->time;
  result->modifiers = (x_x_to_emacs_modifiers (FRAME_DISPLAY_INFO (f),
                                               event->state)
                       | (event->type == ButtonRelease
                          ? up_modifier
                          : down_modifier));

  XSETINT (result->x, event->x);
  XSETINT (result->y, event->y);
  XSETFRAME (result->frame_or_window, f);
  result->arg = Qnil;
  return Qnil;
}

/* Function to report a mouse movement to the mainstream Emacs code.
   The input handler calls this.

   We have received a mouse movement event, which is given in *event.
   If the mouse is over a different glyph than it was last time, tell
   the mainstream emacs code by setting mouse_moved.  If not, ask for
   another motion event, so we can check again the next time it moves.  */

static bool
note_mouse_movement (struct frame *frame, const XMotionEvent *event)
{
  XRectangle *r;
  struct x_display_info *dpyinfo;

  if (!FRAME_X_OUTPUT (frame))
    return false;

  dpyinfo = FRAME_DISPLAY_INFO (frame);
  dpyinfo->last_mouse_movement_time = event->time;
  dpyinfo->last_mouse_motion_frame = frame;
  dpyinfo->last_mouse_motion_x = event->x;
  dpyinfo->last_mouse_motion_y = event->y;

  if (event->window != FRAME_X_WINDOW (frame))
    {
      frame->mouse_moved = true;
      dpyinfo->last_mouse_scroll_bar = NULL;
      note_mouse_highlight (frame, -1, -1);
      dpyinfo->last_mouse_glyph_frame = NULL;
      return true;
    }


  /* Has the mouse moved off the glyph it was on at the last sighting?  */
  r = &dpyinfo->last_mouse_glyph;
  if (frame != dpyinfo->last_mouse_glyph_frame
      || event->x < r->x || event->x >= r->x + r->width
      || event->y < r->y || event->y >= r->y + r->height)
    {
      frame->mouse_moved = true;
      dpyinfo->last_mouse_scroll_bar = NULL;
      note_mouse_highlight (frame, event->x, event->y);
      /* Remember which glyph we're now on.  */
      remember_mouse_glyph (frame, event->x, event->y, r);
      dpyinfo->last_mouse_glyph_frame = frame;
      return true;
    }

  return false;
}

/* Return the current position of the mouse.
   *FP should be a frame which indicates which display to ask about.

   If the mouse movement started in a scroll bar, set *FP, *BAR_WINDOW,
   and *PART to the frame, window, and scroll bar part that the mouse
   is over.  Set *X and *Y to the portion and whole of the mouse's
   position on the scroll bar.

   If the mouse movement started elsewhere, set *FP to the frame the
   mouse is on, *BAR_WINDOW to nil, and *X and *Y to the character cell
   the mouse is over.

   Set *TIMESTAMP to the server time-stamp for the time at which the mouse
   was at this position.

   Don't store anything if we don't have a valid set of values to report.

   This clears the mouse_moved flag, so we can wait for the next mouse
   movement.  */

static void
XTmouse_position (struct frame **fp, int insist, Lisp_Object *bar_window,
                  enum scroll_bar_part *part, Lisp_Object *x, Lisp_Object *y,
                  Time *timestamp)
{
  struct frame *f1;
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (*fp);

  block_input ();

  if (dpyinfo->last_mouse_scroll_bar && insist == 0)
    {
      struct scroll_bar *bar = dpyinfo->last_mouse_scroll_bar;

      if (bar->horizontal)
        x_horizontal_scroll_bar_report_motion (fp, bar_window, part, x, y, timestamp);
      else
        x_scroll_bar_report_motion (fp, bar_window, part, x, y, timestamp);
    }
  else
    {
      Window root;
      int root_x, root_y;

      Window dummy_window;
      int dummy;

      Lisp_Object frame, tail;

      /* Clear the mouse-moved flag for every frame on this display.  */
      FOR_EACH_FRAME (tail, frame)
        if (FRAME_X_P (XFRAME (frame))
            && FRAME_X_DISPLAY (XFRAME (frame)) == FRAME_X_DISPLAY (*fp))
          XFRAME (frame)->mouse_moved = false;

      dpyinfo->last_mouse_scroll_bar = NULL;

      /* Figure out which root window we're on.  */
      XQueryPointer (FRAME_X_DISPLAY (*fp),
                     DefaultRootWindow (FRAME_X_DISPLAY (*fp)),

                     /* The root window which contains the pointer.  */
                     &root,

                     /* Trash which we can't trust if the pointer is on
                        a different screen.  */
                     &dummy_window,

                     /* The position on that root window.  */
                     &root_x, &root_y,

                     /* More trash we can't trust.  */
                     &dummy, &dummy,

                     /* Modifier keys and pointer buttons, about which
                        we don't care.  */
                     (unsigned int *) &dummy);

      /* Now we have a position on the root; find the innermost window
         containing the pointer.  */
      {
        Window win, child;
#ifdef USE_GTK
        Window first_win = 0;
#endif
        int win_x, win_y;
        int parent_x = 0, parent_y = 0;

        win = root;

        /* XTranslateCoordinates can get errors if the window
           structure is changing at the same time this function
           is running.  So at least we must not crash from them.  */

        x_catch_errors (FRAME_X_DISPLAY (*fp));

        if (x_mouse_grabbed (dpyinfo))
          {
            /* If mouse was grabbed on a frame, give coords for that frame
               even if the mouse is now outside it.  */
            XTranslateCoordinates (FRAME_X_DISPLAY (*fp),

                                   /* From-window.  */
                                   root,

                                   /* To-window.  */
                                   FRAME_X_WINDOW (dpyinfo->last_mouse_frame),

                                   /* From-position, to-position.  */
                                   root_x, root_y, &win_x, &win_y,

                                   /* Child of win.  */
                                   &child);
            f1 = dpyinfo->last_mouse_frame;
          }
        else
          {
            while (true)
              {
                XTranslateCoordinates (FRAME_X_DISPLAY (*fp),

                                       /* From-window, to-window.  */
                                       root, win,

                                       /* From-position, to-position.  */
                                       root_x, root_y, &win_x, &win_y,

                                       /* Child of win.  */
                                       &child);

                if (child == None || child == win)
                  {
#ifdef USE_GTK
                    /* On GTK we have not inspected WIN yet.  If it has
                       a frame and that frame has a parent, use it.  */
                    struct frame *f = x_window_to_frame (dpyinfo, win);

                    if (f && FRAME_PARENT_FRAME (f))
                      first_win = win;
#endif
                    break;
                  }
#ifdef USE_GTK
                /* We don't wan't to know the innermost window.  We
                   want the edit window.  For non-Gtk+ the innermost
                   window is the edit window.  For Gtk+ it might not
                   be.  It might be the tool bar for example.  */
                if (x_window_to_frame (dpyinfo, win))
                  /* But don't hurry.  We might find a child frame
                     beneath.  */
                  first_win = win;
#endif
                win = child;
                parent_x = win_x;
                parent_y = win_y;
              }

#ifdef USE_GTK
            if (first_win)
              win = first_win;
#endif

            /* Now we know that:
               win is the innermost window containing the pointer
               (XTC says it has no child containing the pointer),
               win_x and win_y are the pointer's position in it
               (XTC did this the last time through), and
               parent_x and parent_y are the pointer's position in win's parent.
               (They are what win_x and win_y were when win was child.
               If win is the root window, it has no parent, and
               parent_{x,y} are invalid, but that's okay, because we'll
               never use them in that case.)  */

#ifdef USE_GTK
            /* We don't wan't to know the innermost window.  We
               want the edit window.  */
            f1 = x_window_to_frame (dpyinfo, win);
#else
            /* Is win one of our frames?  */
            f1 = x_any_window_to_frame (dpyinfo, win);
#endif

#ifdef USE_X_TOOLKIT
            /* If we end up with the menu bar window, say it's not
               on the frame.  */
            if (f1 != NULL
                && f1->output_data.x->menubar_widget
                && win == XtWindow (f1->output_data.x->menubar_widget))
              f1 = NULL;
#endif /* USE_X_TOOLKIT */
          }

        if (x_had_errors_p (FRAME_X_DISPLAY (*fp)))
          f1 = 0;

        x_uncatch_errors_after_check ();

        /* If not, is it one of our scroll bars?  */
        if (! f1)
          {
            struct scroll_bar *bar;

            bar = x_window_to_scroll_bar (FRAME_X_DISPLAY (*fp), win, 2);

            if (bar)
              {
                f1 = XFRAME (WINDOW_FRAME (XWINDOW (bar->window)));
                win_x = parent_x;
                win_y = parent_y;
              }
          }

        if (f1 == 0 && insist > 0)
          f1 = SELECTED_FRAME ();

        if (f1)
          {
            /* Ok, we found a frame.  Store all the values.
               last_mouse_glyph is a rectangle used to reduce the
               generation of mouse events.  To not miss any motion
               events, we must divide the frame into rectangles of the
               size of the smallest character that could be displayed
               on it, i.e. into the same rectangles that matrices on
               the frame are divided into.  */

            /* FIXME: what if F1 is not an X frame?  */
            dpyinfo = FRAME_DISPLAY_INFO (f1);
            remember_mouse_glyph (f1, win_x, win_y, &dpyinfo->last_mouse_glyph);
            dpyinfo->last_mouse_glyph_frame = f1;

            *bar_window = Qnil;
            *part = 0;
            *fp = f1;
            XSETINT (*x, win_x);
            XSETINT (*y, win_y);
            *timestamp = dpyinfo->last_mouse_movement_time;
          }
      }
    }

  unblock_input ();
}


\f
/***********************************************************************
                               Scroll bars
 ***********************************************************************/

/* Scroll bar support.  */

/* Given an X window ID and a DISPLAY, find the struct scroll_bar which
   manages it.
   This can be called in GC, so we have to make sure to strip off mark
   bits.  */

static struct scroll_bar *
x_window_to_scroll_bar (Display *display, Window window_id, int type)
{
  Lisp_Object tail, frame;

#if defined (USE_GTK) && defined (USE_TOOLKIT_SCROLL_BARS)
  window_id = (Window) xg_get_scroll_id_for_window (display, window_id);
#endif /* USE_GTK  && USE_TOOLKIT_SCROLL_BARS */

  FOR_EACH_FRAME (tail, frame)
    {
      Lisp_Object bar, condemned;

      if (! FRAME_X_P (XFRAME (frame)))
        continue;

      /* Scan this frame's scroll bar list for a scroll bar with the
         right window ID.  */
      condemned = FRAME_CONDEMNED_SCROLL_BARS (XFRAME (frame));
      for (bar = FRAME_SCROLL_BARS (XFRAME (frame));
           /* This trick allows us to search both the ordinary and
              condemned scroll bar lists with one loop.  */
           ! NILP (bar) || (bar = condemned,
                               condemned = Qnil,
                               ! NILP (bar));
           bar = XSCROLL_BAR (bar)->next)
        if (XSCROLL_BAR (bar)->x_window == window_id
            && FRAME_X_DISPLAY (XFRAME (frame)) == display
            && (type = 2
                || (type == 1 && XSCROLL_BAR (bar)->horizontal)
                || (type == 0 && !XSCROLL_BAR (bar)->horizontal)))
          return XSCROLL_BAR (bar);
    }

  return NULL;
}


#if defined USE_LUCID

/* Return the Lucid menu bar WINDOW is part of.  Return null
   if WINDOW is not part of a menu bar.  */

static Widget
x_window_to_menu_bar (Window window)
{
  Lisp_Object tail, frame;

  FOR_EACH_FRAME (tail, frame)
    if (FRAME_X_P (XFRAME (frame)))
      {
        Widget menu_bar = XFRAME (frame)->output_data.x->menubar_widget;

        if (menu_bar && xlwmenu_window_p (menu_bar, window))
          return menu_bar;
      }
  return NULL;
}

#endif /* USE_LUCID */

\f
/************************************************************************
                         Toolkit scroll bars
 ************************************************************************/

#ifdef USE_TOOLKIT_SCROLL_BARS

static void x_send_scroll_bar_event (Lisp_Object, enum scroll_bar_part,
                                     int, int, bool);

/* Lisp window being scrolled.  Set when starting to interact with
   a toolkit scroll bar, reset to nil when ending the interaction.  */

static Lisp_Object window_being_scrolled;

/* Whether this is an Xaw with arrow-scrollbars.  This should imply
   that movements of 1/20 of the screen size are mapped to up/down.  */

#ifndef USE_GTK
/* Id of action hook installed for scroll bars.  */

static XtActionHookId action_hook_id;
static XtActionHookId horizontal_action_hook_id;

static Boolean xaw3d_arrow_scroll;

/* Whether the drag scrolling maintains the mouse at the top of the
   thumb.  If not, resizing the thumb needs to be done more carefully
   to avoid jerkiness.  */

static Boolean xaw3d_pick_top;

/* Action hook installed via XtAppAddActionHook when toolkit scroll
   bars are used..  The hook is responsible for detecting when
   the user ends an interaction with the scroll bar, and generates
   a `end-scroll' SCROLL_BAR_CLICK_EVENT' event if so.  */

static void
xt_action_hook (Widget widget, XtPointer client_data, String action_name,
                XEvent *event, String *params, Cardinal *num_params)
{
  bool scroll_bar_p;
  const char *end_action;

#ifdef USE_MOTIF
  scroll_bar_p = XmIsScrollBar (widget);
  end_action = "Release";
#else /* !USE_MOTIF i.e. use Xaw */
  scroll_bar_p = XtIsSubclass (widget, scrollbarWidgetClass);
  end_action = "EndScroll";
#endif /* USE_MOTIF */

  if (scroll_bar_p
      && strcmp (action_name, end_action) == 0
      && WINDOWP (window_being_scrolled))
    {
      struct window *w;
      struct scroll_bar *bar;

      x_send_scroll_bar_event (window_being_scrolled,
                               scroll_bar_end_scroll, 0, 0, false);
      w = XWINDOW (window_being_scrolled);
      bar = XSCROLL_BAR (w->vertical_scroll_bar);

      if (bar->dragging != -1)
        {
          bar->dragging = -1;
          /* The thumb size is incorrect while dragging: fix it.  */
          set_vertical_scroll_bar (w);
        }
      window_being_scrolled = Qnil;
#if defined (USE_LUCID)
      bar->last_seen_part = scroll_bar_nowhere;
#endif
      /* Xt timeouts no longer needed.  */
      toolkit_scroll_bar_interaction = false;
    }
}


static void
xt_horizontal_action_hook (Widget widget, XtPointer client_data, String action_name,
                           XEvent *event, String *params, Cardinal *num_params)
{
  bool scroll_bar_p;
  const char *end_action;

#ifdef USE_MOTIF
  scroll_bar_p = XmIsScrollBar (widget);
  end_action = "Release";
#else /* !USE_MOTIF i.e. use Xaw */
  scroll_bar_p = XtIsSubclass (widget, scrollbarWidgetClass);
  end_action = "EndScroll";
#endif /* USE_MOTIF */

  if (scroll_bar_p
      && strcmp (action_name, end_action) == 0
      && WINDOWP (window_being_scrolled))
    {
      struct window *w;
      struct scroll_bar *bar;

      x_send_scroll_bar_event (window_being_scrolled,
                               scroll_bar_end_scroll, 0, 0, true);
      w = XWINDOW (window_being_scrolled);
      if (!NILP (w->horizontal_scroll_bar))
        {
          bar = XSCROLL_BAR (w->horizontal_scroll_bar);
          if (bar->dragging != -1)
            {
              bar->dragging = -1;
              /* The thumb size is incorrect while dragging: fix it.  */
              set_horizontal_scroll_bar (w);
            }
          window_being_scrolled = Qnil;
#if defined (USE_LUCID)
          bar->last_seen_part = scroll_bar_nowhere;
#endif
          /* Xt timeouts no longer needed.  */
          toolkit_scroll_bar_interaction = false;
        }
    }
}
#endif /* not USE_GTK */

/* Send a client message with message type Xatom_Scrollbar for a
   scroll action to the frame of WINDOW.  PART is a value identifying
   the part of the scroll bar that was clicked on.  PORTION is the
   amount to scroll of a whole of WHOLE.  */

static void
x_send_scroll_bar_event (Lisp_Object window, enum scroll_bar_part part,
                         int portion, int whole, bool horizontal)
{
  XEvent event;
  XClientMessageEvent *ev = &event.xclient;
  struct window *w = XWINDOW (window);
  struct frame *f = XFRAME (w->frame);
  intptr_t iw = (intptr_t) w;
  verify (INTPTR_WIDTH <= 64);
  int sign_shift = INTPTR_WIDTH - 32;

  block_input ();

  /* Construct a ClientMessage event to send to the frame.  */
  ev->type = ClientMessage;
  ev->message_type = (horizontal
                      ? FRAME_DISPLAY_INFO (f)->Xatom_Horizontal_Scrollbar
                      : FRAME_DISPLAY_INFO (f)->Xatom_Scrollbar);
  ev->display = FRAME_X_DISPLAY (f);
  ev->window = FRAME_X_WINDOW (f);
  ev->format = 32;

  /* A 32-bit X client on a 64-bit X server can pass a window pointer
     as-is.  A 64-bit client on a 32-bit X server is in trouble
     because a pointer does not fit and would be truncated while
     passing through the server.  So use two slots and hope that X12
     will resolve such issues someday.  */
  ev->data.l[0] = iw >> 31 >> 1;
  ev->data.l[1] = sign_shift <= 0 ? iw : iw << sign_shift >> sign_shift;
  ev->data.l[2] = part;
  ev->data.l[3] = portion;
  ev->data.l[4] = whole;

  /* Make Xt timeouts work while the scroll bar is active.  */
#ifdef USE_X_TOOLKIT
  toolkit_scroll_bar_interaction = true;
  x_activate_timeout_atimer ();
#endif

  /* Setting the event mask to zero means that the message will
     be sent to the client that created the window, and if that
     window no longer exists, no event will be sent.  */
  XSendEvent (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), False, 0, &event);
  unblock_input ();
}


/* Transform a scroll bar ClientMessage EVENT to an Emacs input event
   in *IEVENT.  */

static void
x_scroll_bar_to_input_event (const XEvent *event,
                             struct input_event *ievent)
{
  const XClientMessageEvent *ev = &event->xclient;
  Lisp_Object window;
  struct window *w;

  /* See the comment in the function above.  */
  intptr_t iw0 = ev->data.l[0];
  intptr_t iw1 = ev->data.l[1];
  intptr_t iw = (iw0 << 31 << 1) + (iw1 & 0xffffffffu);
  w = (struct window *) iw;

  XSETWINDOW (window, w);

  ievent->kind = SCROLL_BAR_CLICK_EVENT;
  ievent->frame_or_window = window;
  ievent->arg = Qnil;
#ifdef USE_GTK
  ievent->timestamp = CurrentTime;
#else
  ievent->timestamp =
    XtLastTimestampProcessed (FRAME_X_DISPLAY (XFRAME (w->frame)));
#endif
  ievent->code = 0;
  ievent->part = ev->data.l[2];
  ievent->x = make_number (ev->data.l[3]);
  ievent->y = make_number (ev->data.l[4]);
  ievent->modifiers = 0;
}

/* Transform a horizontal scroll bar ClientMessage EVENT to an Emacs
   input event in *IEVENT.  */

static void
x_horizontal_scroll_bar_to_input_event (const XEvent *event,
                                        struct input_event *ievent)
{
  const XClientMessageEvent *ev = &event->xclient;
  Lisp_Object window;
  struct window *w;

  /* See the comment in the function above.  */
  intptr_t iw0 = ev->data.l[0];
  intptr_t iw1 = ev->data.l[1];
  intptr_t iw = (iw0 << 31 << 1) + (iw1 & 0xffffffffu);
  w = (struct window *) iw;

  XSETWINDOW (window, w);

  ievent->kind = HORIZONTAL_SCROLL_BAR_CLICK_EVENT;
  ievent->frame_or_window = window;
  ievent->arg = Qnil;
#ifdef USE_GTK
  ievent->timestamp = CurrentTime;
#else
  ievent->timestamp =
    XtLastTimestampProcessed (FRAME_X_DISPLAY (XFRAME (w->frame)));
#endif
  ievent->code = 0;
  ievent->part = ev->data.l[2];
  ievent->x = make_number (ev->data.l[3]);
  ievent->y = make_number (ev->data.l[4]);
  ievent->modifiers = 0;
}


#ifdef USE_MOTIF

/* Minimum and maximum values used for Motif scroll bars.  */

#define XM_SB_MAX 10000000

/* Scroll bar callback for Motif scroll bars.  WIDGET is the scroll
   bar widget.  CLIENT_DATA is a pointer to the scroll_bar structure.
   CALL_DATA is a pointer to a XmScrollBarCallbackStruct.  */

static void
xm_scroll_callback (Widget widget, XtPointer client_data, XtPointer call_data)
{
  struct scroll_bar *bar = client_data;
  XmScrollBarCallbackStruct *cs = call_data;
  enum scroll_bar_part part = scroll_bar_nowhere;
  bool horizontal = bar->horizontal;
  int whole = 0, portion = 0;

  switch (cs->reason)
    {
    case XmCR_DECREMENT:
      bar->dragging = -1;
      part = horizontal ? scroll_bar_left_arrow : scroll_bar_up_arrow;
      break;

    case XmCR_INCREMENT:
      bar->dragging = -1;
      part = horizontal ? scroll_bar_right_arrow : scroll_bar_down_arrow;
      break;

    case XmCR_PAGE_DECREMENT:
      bar->dragging = -1;
      part = horizontal ? scroll_bar_before_handle : scroll_bar_above_handle;
      break;

    case XmCR_PAGE_INCREMENT:
      bar->dragging = -1;
      part = horizontal ? scroll_bar_after_handle : scroll_bar_below_handle;
      break;

    case XmCR_TO_TOP:
      bar->dragging = -1;
      part = horizontal ? scroll_bar_to_leftmost : scroll_bar_to_top;
      break;

    case XmCR_TO_BOTTOM:
      bar->dragging = -1;
      part = horizontal ? scroll_bar_to_rightmost : scroll_bar_to_bottom;
      break;

    case XmCR_DRAG:
      {
        int slider_size;

        block_input ();
        XtVaGetValues (widget, XmNsliderSize, &slider_size, NULL);
        unblock_input ();

        if (horizontal)
          {
            portion = bar->whole * ((float)cs->value / XM_SB_MAX);
            whole = bar->whole * ((float)(XM_SB_MAX - slider_size) / XM_SB_MAX);
            portion = min (portion, whole);
            part = scroll_bar_horizontal_handle;
          }
        else
          {
            whole = XM_SB_MAX - slider_size;
            portion = min (cs->value, whole);
            part = scroll_bar_handle;
          }

        bar->dragging = cs->value;
      }
      break;

    case XmCR_VALUE_CHANGED:
      break;
    };

  if (part != scroll_bar_nowhere)
    {
      window_being_scrolled = bar->window;
      x_send_scroll_bar_event (bar->window, part, portion, whole,
                               bar->horizontal);
    }
}

#elif defined USE_GTK

/* Scroll bar callback for GTK scroll bars.  WIDGET is the scroll
   bar widget.  DATA is a pointer to the scroll_bar structure. */

static gboolean
xg_scroll_callback (GtkRange     *range,
                    GtkScrollType scroll,
                    gdouble       value,
                    gpointer      user_data)
{
  int whole = 0, portion = 0;
  struct scroll_bar *bar = user_data;
  enum scroll_bar_part part = scroll_bar_nowhere;
  GtkAdjustment *adj = GTK_ADJUSTMENT (gtk_range_get_adjustment (range));
  struct frame *f = g_object_get_data (G_OBJECT (range), XG_FRAME_DATA);

  if (xg_ignore_gtk_scrollbar) return false;

  switch (scroll)
    {
    case GTK_SCROLL_JUMP:
      /* Buttons 1 2 or 3 must be grabbed.  */
      if (FRAME_DISPLAY_INFO (f)->grabbed != 0
          && FRAME_DISPLAY_INFO (f)->grabbed < (1 << 4))
        {
          if (bar->horizontal)
            {
              part = scroll_bar_horizontal_handle;
              whole = (int)(gtk_adjustment_get_upper (adj) -
                            gtk_adjustment_get_page_size (adj));
              portion = min ((int)value, whole);
              bar->dragging = portion;
            }
          else
            {
              part = scroll_bar_handle;
              whole = gtk_adjustment_get_upper (adj) -
                gtk_adjustment_get_page_size (adj);
              portion = min ((int)value, whole);
              bar->dragging = portion;
            }
        }
      break;
    case GTK_SCROLL_STEP_BACKWARD:
      part = (bar->horizontal
              ? scroll_bar_left_arrow : scroll_bar_up_arrow);
      bar->dragging = -1;
      break;
    case GTK_SCROLL_STEP_FORWARD:
      part = (bar->horizontal
              ? scroll_bar_right_arrow : scroll_bar_down_arrow);
      bar->dragging = -1;
      break;
    case GTK_SCROLL_PAGE_BACKWARD:
      part = (bar->horizontal
              ? scroll_bar_before_handle : scroll_bar_above_handle);
      bar->dragging = -1;
      break;
    case GTK_SCROLL_PAGE_FORWARD:
      part = (bar->horizontal
              ? scroll_bar_after_handle : scroll_bar_below_handle);
      bar->dragging = -1;
      break;
    default:
      break;
    }

  if (part != scroll_bar_nowhere)
    {
      window_being_scrolled = bar->window;
      x_send_scroll_bar_event (bar->window, part, portion, whole,
                               bar->horizontal);
    }

  return false;
}

/* Callback for button release. Sets dragging to -1 when dragging is done.  */

static gboolean
xg_end_scroll_callback (GtkWidget *widget,
                        GdkEventButton *event,
                        gpointer user_data)
{
  struct scroll_bar *bar = user_data;
  bar->dragging = -1;
  if (WINDOWP (window_being_scrolled))
    {
      x_send_scroll_bar_event (window_being_scrolled,
                               scroll_bar_end_scroll, 0, 0, bar->horizontal);
      window_being_scrolled = Qnil;
    }

  return false;
}


#else /* not USE_GTK and not USE_MOTIF */

/* Xaw scroll bar callback.  Invoked when the thumb is dragged.
   WIDGET is the scroll bar widget.  CLIENT_DATA is a pointer to the
   scroll bar struct.  CALL_DATA is a pointer to a float saying where
   the thumb is.  */

static void
xaw_jump_callback (Widget widget, XtPointer client_data, XtPointer call_data)
{
  struct scroll_bar *bar = client_data;
  float *top_addr = call_data;
  float top = *top_addr;
  float shown;
  int whole, portion, height, width;
  enum scroll_bar_part part;
  bool horizontal = bar->horizontal;


  if (horizontal)
    {
      /* Get the size of the thumb, a value between 0 and 1.  */
      block_input ();
      XtVaGetValues (widget, XtNshown, &shown, XtNwidth, &width, NULL);
      unblock_input ();

      if (shown < 1)
        {
          whole = bar->whole - (shown * bar->whole);
          portion = min (top * bar->whole, whole);
        }
      else
        {
          whole = bar->whole;
          portion = 0;
        }

      part = scroll_bar_horizontal_handle;
    }
  else
    {
      /* Get the size of the thumb, a value between 0 and 1.  */
      block_input ();
      XtVaGetValues (widget, XtNshown, &shown, XtNheight, &height, NULL);
      unblock_input ();

      whole = 10000000;
      portion = shown < 1 ? top * whole : 0;

      if (shown < 1 && (eabs (top + shown - 1) < 1.0f / height))
        /* Some derivatives of Xaw refuse to shrink the thumb when you reach
           the bottom, so we force the scrolling whenever we see that we're
           too close to the bottom (in x_set_toolkit_scroll_bar_thumb
           we try to ensure that we always stay two pixels away from the
           bottom).  */
        part = scroll_bar_down_arrow;
      else
        part = scroll_bar_handle;
    }

  window_being_scrolled = bar->window;
  bar->dragging = portion;
  bar->last_seen_part = part;
  x_send_scroll_bar_event (bar->window, part, portion, whole, bar->horizontal);
}


/* Xaw scroll bar callback.  Invoked for incremental scrolling.,
   i.e. line or page up or down.  WIDGET is the Xaw scroll bar
   widget.  CLIENT_DATA is a pointer to the scroll_bar structure for
   the scroll bar.  CALL_DATA is an integer specifying the action that
   has taken place.  Its magnitude is in the range 0..height of the
   scroll bar.  Negative values mean scroll towards buffer start.
   Values < height of scroll bar mean line-wise movement.  */

static void
xaw_scroll_callback (Widget widget, XtPointer client_data, XtPointer call_data)
{
  struct scroll_bar *bar = client_data;
  /* The position really is stored cast to a pointer.  */
  int position = (intptr_t) call_data;
  Dimension height, width;
  enum scroll_bar_part part;

  if (bar->horizontal)
    {
      /* Get the width of the scroll bar.  */
      block_input ();
      XtVaGetValues (widget, XtNwidth, &width, NULL);
      unblock_input ();

      if (eabs (position) >= width)
        part = (position < 0) ? scroll_bar_before_handle : scroll_bar_after_handle;

      /* If Xaw3d was compiled with ARROW_SCROLLBAR,
         it maps line-movement to call_data = max(5, height/20).  */
      else if (xaw3d_arrow_scroll && eabs (position) <= max (5, width / 20))
        part = (position < 0) ? scroll_bar_left_arrow : scroll_bar_right_arrow;
      else
        part = scroll_bar_move_ratio;

      window_being_scrolled = bar->window;
      bar->dragging = -1;
      bar->last_seen_part = part;
      x_send_scroll_bar_event (bar->window, part, position, width,
                               bar->horizontal);
    }
  else
    {

      /* Get the height of the scroll bar.  */
      block_input ();
      XtVaGetValues (widget, XtNheight, &height, NULL);
      unblock_input ();

      if (eabs (position) >= height)
        part = (position < 0) ? scroll_bar_above_handle : scroll_bar_below_handle;

      /* If Xaw3d was compiled with ARROW_SCROLLBAR,
         it maps line-movement to call_data = max(5, height/20).  */
      else if (xaw3d_arrow_scroll && eabs (position) <= max (5, height / 20))
        part = (position < 0) ? scroll_bar_up_arrow : scroll_bar_down_arrow;
      else
        part = scroll_bar_move_ratio;

      window_being_scrolled = bar->window;
      bar->dragging = -1;
      bar->last_seen_part = part;
      x_send_scroll_bar_event (bar->window, part, position, height,
                               bar->horizontal);
    }
}

#endif /* not USE_GTK and not USE_MOTIF */

#define SCROLL_BAR_NAME "verticalScrollBar"
#define SCROLL_BAR_HORIZONTAL_NAME "horizontalScrollBar"

/* Create the widget for scroll bar BAR on frame F.  Record the widget
   and X window of the scroll bar in BAR.  */

#ifdef USE_GTK
static void
x_create_toolkit_scroll_bar (struct frame *f, struct scroll_bar *bar)
{
  const char *scroll_bar_name = SCROLL_BAR_NAME;

  block_input ();
  xg_create_scroll_bar (f, bar, G_CALLBACK (xg_scroll_callback),
                        G_CALLBACK (xg_end_scroll_callback),
                        scroll_bar_name);
  unblock_input ();
}

static void
x_create_horizontal_toolkit_scroll_bar (struct frame *f, struct scroll_bar *bar)
{
  const char *scroll_bar_name = SCROLL_BAR_HORIZONTAL_NAME;

  block_input ();
  xg_create_horizontal_scroll_bar (f, bar, G_CALLBACK (xg_scroll_callback),
                                   G_CALLBACK (xg_end_scroll_callback),
                                   scroll_bar_name);
  unblock_input ();
}

#else /* not USE_GTK */

static void
x_create_toolkit_scroll_bar (struct frame *f, struct scroll_bar *bar)
{
  Window xwindow;
  Widget widget;
  Arg av[20];
  int ac = 0;
  const char *scroll_bar_name = SCROLL_BAR_NAME;
  unsigned long pixel;

  block_input ();

#ifdef USE_MOTIF
  /* Set resources.  Create the widget.  */
  XtSetArg (av[ac], XtNmappedWhenManaged, False); ++ac;
  XtSetArg (av[ac], XmNminimum, 0); ++ac;
  XtSetArg (av[ac], XmNmaximum, XM_SB_MAX); ++ac;
  XtSetArg (av[ac], XmNorientation, XmVERTICAL); ++ac;
  XtSetArg (av[ac], XmNprocessingDirection, XmMAX_ON_BOTTOM), ++ac;
  XtSetArg (av[ac], XmNincrement, 1); ++ac;
  XtSetArg (av[ac], XmNpageIncrement, 1); ++ac;

  pixel = f->output_data.x->scroll_bar_foreground_pixel;
  if (pixel != -1)
    {
      XtSetArg (av[ac], XmNforeground, pixel);
      ++ac;
    }

  pixel = f->output_data.x->scroll_bar_background_pixel;
  if (pixel != -1)
    {
      XtSetArg (av[ac], XmNbackground, pixel);
      ++ac;
    }

  widget = XmCreateScrollBar (f->output_data.x->edit_widget,
                              (char *) scroll_bar_name, av, ac);

  /* Add one callback for everything that can happen.  */
  XtAddCallback (widget, XmNdecrementCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNdragCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNincrementCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNpageDecrementCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNpageIncrementCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNtoBottomCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNtoTopCallback, xm_scroll_callback,
                 (XtPointer) bar);

  /* Realize the widget.  Only after that is the X window created.  */
  XtRealizeWidget (widget);

  /* Set the cursor to an arrow.  I didn't find a resource to do that.
     And I'm wondering why it hasn't an arrow cursor by default.  */
  XDefineCursor (XtDisplay (widget), XtWindow (widget),
                 f->output_data.x->nontext_cursor);

#else /* !USE_MOTIF i.e. use Xaw */

  /* Set resources.  Create the widget.  The background of the
     Xaw3d scroll bar widget is a little bit light for my taste.
     We don't alter it here to let users change it according
     to their taste with `emacs*verticalScrollBar.background: xxx'.  */
  XtSetArg (av[ac], XtNmappedWhenManaged, False); ++ac;
  XtSetArg (av[ac], XtNorientation, XtorientVertical); ++ac;
  /* For smoother scrolling with Xaw3d   -sm */
  /* XtSetArg (av[ac], XtNpickTop, True); ++ac; */

  pixel = f->output_data.x->scroll_bar_foreground_pixel;
  if (pixel != -1)
    {
      XtSetArg (av[ac], XtNforeground, pixel);
      ++ac;
    }

  pixel = f->output_data.x->scroll_bar_background_pixel;
  if (pixel != -1)
    {
      XtSetArg (av[ac], XtNbackground, pixel);
      ++ac;
    }

  /* Top/bottom shadow colors.  */

  /* Allocate them, if necessary.  */
  if (f->output_data.x->scroll_bar_top_shadow_pixel == -1)
    {
      pixel = f->output_data.x->scroll_bar_background_pixel;
      if (pixel != -1)
        {
          if (!x_alloc_lighter_color (f, FRAME_X_DISPLAY (f),
                                      FRAME_X_COLORMAP (f),
                                      &pixel, 1.2, 0x8000))
            pixel = -1;
          f->output_data.x->scroll_bar_top_shadow_pixel = pixel;
        }
    }
  if (f->output_data.x->scroll_bar_bottom_shadow_pixel == -1)
    {
      pixel = f->output_data.x->scroll_bar_background_pixel;
      if (pixel != -1)
        {
          if (!x_alloc_lighter_color (f, FRAME_X_DISPLAY (f),
                                      FRAME_X_COLORMAP (f),
                                      &pixel, 0.6, 0x4000))
            pixel = -1;
          f->output_data.x->scroll_bar_bottom_shadow_pixel = pixel;
        }
    }

#ifdef XtNbeNiceToColormap
  /* Tell the toolkit about them.  */
  if (f->output_data.x->scroll_bar_top_shadow_pixel == -1
      || f->output_data.x->scroll_bar_bottom_shadow_pixel == -1)
    /* We tried to allocate a color for the top/bottom shadow, and
       failed, so tell Xaw3d to use dithering instead.   */
    /* But only if we have a small colormap.  Xaw3d can allocate nice
       colors itself.  */
    {
      XtSetArg (av[ac], XtNbeNiceToColormap,
                DefaultDepthOfScreen (FRAME_X_SCREEN (f)) < 16);
      ++ac;
    }
  else
    /* Tell what colors Xaw3d should use for the top/bottom shadow, to
       be more consistent with other emacs 3d colors, and since Xaw3d is
       not good at dealing with allocation failure.  */
    {
      /* This tells Xaw3d to use real colors instead of dithering for
         the shadows.  */
      XtSetArg (av[ac], XtNbeNiceToColormap, False);
      ++ac;

      /* Specify the colors.  */
      pixel = f->output_data.x->scroll_bar_top_shadow_pixel;
      if (pixel != -1)
        {
          XtSetArg (av[ac], XtNtopShadowPixel, pixel);
          ++ac;
        }
      pixel = f->output_data.x->scroll_bar_bottom_shadow_pixel;
      if (pixel != -1)
        {
          XtSetArg (av[ac], XtNbottomShadowPixel, pixel);
          ++ac;
        }
    }
#endif

  widget = XtCreateWidget (scroll_bar_name, scrollbarWidgetClass,
                           f->output_data.x->edit_widget, av, ac);

  {
    char const *initial = "";
    char const *val = initial;
    XtVaGetValues (widget, XtNscrollVCursor, (XtPointer) &val,
#ifdef XtNarrowScrollbars
                   XtNarrowScrollbars, (XtPointer) &xaw3d_arrow_scroll,
#endif
                   XtNpickTop, (XtPointer) &xaw3d_pick_top, NULL);
    if (xaw3d_arrow_scroll || val == initial)
      { /* ARROW_SCROLL */
        xaw3d_arrow_scroll = True;
        /* Isn't that just a personal preference ?   --Stef */
        XtVaSetValues (widget, XtNcursorName, "top_left_arrow", NULL);
      }
  }

  /* Define callbacks.  */
  XtAddCallback (widget, XtNjumpProc, xaw_jump_callback, (XtPointer) bar);
  XtAddCallback (widget, XtNscrollProc, xaw_scroll_callback,
                 (XtPointer) bar);

  /* Realize the widget.  Only after that is the X window created.  */
  XtRealizeWidget (widget);

#endif /* !USE_MOTIF */

  /* Install an action hook that lets us detect when the user
     finishes interacting with a scroll bar.  */
  if (action_hook_id == 0)
    action_hook_id = XtAppAddActionHook (Xt_app_con, xt_action_hook, 0);

  /* Remember X window and widget in the scroll bar vector.  */
  SET_SCROLL_BAR_X_WIDGET (bar, widget);
  xwindow = XtWindow (widget);
  bar->x_window = xwindow;
  bar->whole = 1;
  bar->horizontal = false;

  unblock_input ();
}

static void
x_create_horizontal_toolkit_scroll_bar (struct frame *f, struct scroll_bar *bar)
{
  Window xwindow;
  Widget widget;
  Arg av[20];
  int ac = 0;
  const char *scroll_bar_name = SCROLL_BAR_HORIZONTAL_NAME;
  unsigned long pixel;

  block_input ();

#ifdef USE_MOTIF
  /* Set resources.  Create the widget.  */
  XtSetArg (av[ac], XtNmappedWhenManaged, False); ++ac;
  XtSetArg (av[ac], XmNminimum, 0); ++ac;
  XtSetArg (av[ac], XmNmaximum, XM_SB_MAX); ++ac;
  XtSetArg (av[ac], XmNorientation, XmHORIZONTAL); ++ac;
  XtSetArg (av[ac], XmNprocessingDirection, XmMAX_ON_RIGHT), ++ac;
  XtSetArg (av[ac], XmNincrement, 1); ++ac;
  XtSetArg (av[ac], XmNpageIncrement, 1); ++ac;

  pixel = f->output_data.x->scroll_bar_foreground_pixel;
  if (pixel != -1)
    {
      XtSetArg (av[ac], XmNforeground, pixel);
      ++ac;
    }

  pixel = f->output_data.x->scroll_bar_background_pixel;
  if (pixel != -1)
    {
      XtSetArg (av[ac], XmNbackground, pixel);
      ++ac;
    }

  widget = XmCreateScrollBar (f->output_data.x->edit_widget,
                              (char *) scroll_bar_name, av, ac);

  /* Add one callback for everything that can happen.  */
  XtAddCallback (widget, XmNdecrementCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNdragCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNincrementCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNpageDecrementCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNpageIncrementCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNtoBottomCallback, xm_scroll_callback,
                 (XtPointer) bar);
  XtAddCallback (widget, XmNtoTopCallback, xm_scroll_callback,
                 (XtPointer) bar);

  /* Realize the widget.  Only after that is the X window created.  */
  XtRealizeWidget (widget);

  /* Set the cursor to an arrow.  I didn't find a resource to do that.
     And I'm wondering why it hasn't an arrow cursor by default.  */
  XDefineCursor (XtDisplay (widget), XtWindow (widget),
                 f->output_data.x->nontext_cursor);

#else /* !USE_MOTIF i.e. use Xaw */

  /* Set resources.  Create the widget.  The background of the
     Xaw3d scroll bar widget is a little bit light for my taste.
     We don't alter it here to let users change it according
     to their taste with `emacs*verticalScrollBar.background: xxx'.  */
  XtSetArg (av[ac], XtNmappedWhenManaged, False); ++ac;
  XtSetArg (av[ac], XtNorientation, XtorientHorizontal); ++ac;
  /* For smoother scrolling with Xaw3d   -sm */
  /* XtSetArg (av[ac], XtNpickTop, True); ++ac; */

  pixel = f->output_data.x->scroll_bar_foreground_pixel;
  if (pixel != -1)
    {
      XtSetArg (av[ac], XtNforeground, pixel);
      ++ac;
    }

  pixel = f->output_data.x->scroll_bar_background_pixel;
  if (pixel != -1)
    {
      XtSetArg (av[ac], XtNbackground, pixel);
      ++ac;
    }

  /* Top/bottom shadow colors.  */

  /* Allocate them, if necessary.  */
  if (f->output_data.x->scroll_bar_top_shadow_pixel == -1)
    {
      pixel = f->output_data.x->scroll_bar_background_pixel;
      if (pixel != -1)
        {
          if (!x_alloc_lighter_color (f, FRAME_X_DISPLAY (f),
                                      FRAME_X_COLORMAP (f),
                                      &pixel, 1.2, 0x8000))
            pixel = -1;
          f->output_data.x->scroll_bar_top_shadow_pixel = pixel;
        }
    }
  if (f->output_data.x->scroll_bar_bottom_shadow_pixel == -1)
    {
      pixel = f->output_data.x->scroll_bar_background_pixel;
      if (pixel != -1)
        {
          if (!x_alloc_lighter_color (f, FRAME_X_DISPLAY (f),
                                      FRAME_X_COLORMAP (f),
                                      &pixel, 0.6, 0x4000))
            pixel = -1;
          f->output_data.x->scroll_bar_bottom_shadow_pixel = pixel;
        }
    }

#ifdef XtNbeNiceToColormap
  /* Tell the toolkit about them.  */
  if (f->output_data.x->scroll_bar_top_shadow_pixel == -1
      || f->output_data.x->scroll_bar_bottom_shadow_pixel == -1)
    /* We tried to allocate a color for the top/bottom shadow, and
       failed, so tell Xaw3d to use dithering instead.   */
    /* But only if we have a small colormap.  Xaw3d can allocate nice
       colors itself.  */
    {
      XtSetArg (av[ac], XtNbeNiceToColormap,
                DefaultDepthOfScreen (FRAME_X_SCREEN (f)) < 16);
      ++ac;
    }
  else
    /* Tell what colors Xaw3d should use for the top/bottom shadow, to
       be more consistent with other emacs 3d colors, and since Xaw3d is
       not good at dealing with allocation failure.  */
    {
      /* This tells Xaw3d to use real colors instead of dithering for
         the shadows.  */
      XtSetArg (av[ac], XtNbeNiceToColormap, False);
      ++ac;

      /* Specify the colors.  */
      pixel = f->output_data.x->scroll_bar_top_shadow_pixel;
      if (pixel != -1)
        {
          XtSetArg (av[ac], XtNtopShadowPixel, pixel);
          ++ac;
        }
      pixel = f->output_data.x->scroll_bar_bottom_shadow_pixel;
      if (pixel != -1)
        {
          XtSetArg (av[ac], XtNbottomShadowPixel, pixel);
          ++ac;
        }
    }
#endif

  widget = XtCreateWidget (scroll_bar_name, scrollbarWidgetClass,
                           f->output_data.x->edit_widget, av, ac);

  {
    char const *initial = "";
    char const *val = initial;
    XtVaGetValues (widget, XtNscrollVCursor, (XtPointer) &val,
#ifdef XtNarrowScrollbars
                   XtNarrowScrollbars, (XtPointer) &xaw3d_arrow_scroll,
#endif
                   XtNpickTop, (XtPointer) &xaw3d_pick_top, NULL);
    if (xaw3d_arrow_scroll || val == initial)
      { /* ARROW_SCROLL */
        xaw3d_arrow_scroll = True;
        /* Isn't that just a personal preference ?   --Stef */
        XtVaSetValues (widget, XtNcursorName, "top_left_arrow", NULL);
      }
  }

  /* Define callbacks.  */
  XtAddCallback (widget, XtNjumpProc, xaw_jump_callback, (XtPointer) bar);
  XtAddCallback (widget, XtNscrollProc, xaw_scroll_callback,
                 (XtPointer) bar);

  /* Realize the widget.  Only after that is the X window created.  */
  XtRealizeWidget (widget);

#endif /* !USE_MOTIF */

  /* Install an action hook that lets us detect when the user
     finishes interacting with a scroll bar.  */
  if (horizontal_action_hook_id == 0)
   horizontal_action_hook_id
     = XtAppAddActionHook (Xt_app_con, xt_horizontal_action_hook, 0);

  /* Remember X window and widget in the scroll bar vector.  */
  SET_SCROLL_BAR_X_WIDGET (bar, widget);
  xwindow = XtWindow (widget);
  bar->x_window = xwindow;
  bar->whole = 1;
  bar->horizontal = true;

  unblock_input ();
}
#endif /* not USE_GTK */


/* Set the thumb size and position of scroll bar BAR.  We are currently
   displaying PORTION out of a whole WHOLE, and our position POSITION.  */

#ifdef USE_GTK
static void
x_set_toolkit_scroll_bar_thumb (struct scroll_bar *bar, int portion, int position, int whole)
{
  xg_set_toolkit_scroll_bar_thumb (bar, portion, position, whole);
}

static void
x_set_toolkit_horizontal_scroll_bar_thumb (struct scroll_bar *bar, int portion, int position, int whole)
{
  xg_set_toolkit_horizontal_scroll_bar_thumb (bar, portion, position, whole);
}

#else /* not USE_GTK */
static void
x_set_toolkit_scroll_bar_thumb (struct scroll_bar *bar, int portion, int position,
                                int whole)
{
  struct frame *f = XFRAME (WINDOW_FRAME (XWINDOW (bar->window)));
  Widget widget = SCROLL_BAR_X_WIDGET (FRAME_X_DISPLAY (f), bar);
  float top, shown;

  block_input ();

#ifdef USE_MOTIF

  if (scroll_bar_adjust_thumb_portion_p)
    {
      /* We use an estimate of 30 chars per line rather than the real
         `portion' value.  This has the disadvantage that the thumb size
         is not very representative, but it makes our life a lot easier.
         Otherwise, we have to constantly adjust the thumb size, which
         we can't always do quickly enough: while dragging, the size of
         the thumb might prevent the user from dragging the thumb all the
         way to the end.  but Motif and some versions of Xaw3d don't allow
         updating the thumb size while dragging.  Also, even if we can update
         its size, the update will often happen too late.
         If you don't believe it, check out revision 1.650 of xterm.c to see
         what hoops we were going through and the still poor behavior we got.  */
      portion = WINDOW_TOTAL_LINES (XWINDOW (bar->window)) * 30;
      /* When the thumb is at the bottom, position == whole.
         So we need to increase `whole' to make space for the thumb.  */
      whole += portion;
    }

  if (whole <= 0)
    top = 0, shown = 1;
  else
    {
      top = (float) position / whole;
      shown = (float) portion / whole;
    }

  if (bar->dragging == -1)
    {
      int size, value;

      /* Slider size.  Must be in the range [1 .. MAX - MIN] where MAX
         is the scroll bar's maximum and MIN is the scroll bar's minimum
         value.  */
      size = clip_to_bounds (1, shown * XM_SB_MAX, XM_SB_MAX);

      /* Position.  Must be in the range [MIN .. MAX - SLIDER_SIZE].  */
      value = top * XM_SB_MAX;
      value = min (value, XM_SB_MAX - size);

      XmScrollBarSetValues (widget, value, size, 0, 0, False);
    }
#else /* !USE_MOTIF i.e. use Xaw */

  if (whole == 0)
    top = 0, shown = 1;
  else
    {
      top = (float) position / whole;
      shown = (float) portion / whole;
    }

  {
    float old_top, old_shown;
    Dimension height;
    XtVaGetValues (widget,
                   XtNtopOfThumb, &old_top,
                   XtNshown, &old_shown,
                   XtNheight, &height,
                   NULL);

    /* Massage the top+shown values.  */
    if (bar->dragging == -1 || bar->last_seen_part == scroll_bar_down_arrow)
      top = max (0, min (1, top));
    else
      top = old_top;
#if ! defined (HAVE_XAW3D)
    /* With Xaw, 'top' values too closer to 1.0 may
       cause the thumb to disappear.  Fix that.  */
    top = min (top, 0.99f);
#endif
    /* Keep two pixels available for moving the thumb down.  */
    shown = max (0, min (1 - top - (2.0f / height), shown));
#if ! defined (HAVE_XAW3D)
    /* Likewise with too small 'shown'.  */
    shown = max (shown, 0.01f);
#endif

    /* If the call to XawScrollbarSetThumb below doesn't seem to
       work, check that 'NARROWPROTO' is defined in src/config.h.
       If this is not so, most likely you need to fix configure.  */
    if (top != old_top || shown != old_shown)
      {
        if (bar->dragging == -1)
          XawScrollbarSetThumb (widget, top, shown);
        else
          {
            /* Try to make the scrolling a tad smoother.  */
            if (!xaw3d_pick_top)
              shown = min (shown, old_shown);

            XawScrollbarSetThumb (widget, top, shown);
          }
      }
  }
#endif /* !USE_MOTIF */

  unblock_input ();
}

static void
x_set_toolkit_horizontal_scroll_bar_thumb (struct scroll_bar *bar, int portion, int position,
                                int whole)
{
  struct frame *f = XFRAME (WINDOW_FRAME (XWINDOW (bar->window)));
  Widget widget = SCROLL_BAR_X_WIDGET (FRAME_X_DISPLAY (f), bar);
  float top, shown;

  block_input ();

#ifdef USE_MOTIF
  bar->whole = whole;
  shown = (float) portion / whole;
  top = (float) position / (whole - portion);
  {
    int size = clip_to_bounds (1, shown * XM_SB_MAX, XM_SB_MAX);
    int value = clip_to_bounds (0, top * (XM_SB_MAX - size), XM_SB_MAX - size);

    XmScrollBarSetValues (widget, value, size, 0, 0, False);
  }
#else /* !USE_MOTIF i.e. use Xaw */
  bar->whole = whole;
  if (whole == 0)
    top = 0, shown = 1;
  else
    {
      top = (float) position / whole;
      shown = (float) portion / whole;
    }

  {
    float old_top, old_shown;
    Dimension height;
    XtVaGetValues (widget,
                   XtNtopOfThumb, &old_top,
                   XtNshown, &old_shown,
                   XtNheight, &height,
                   NULL);

#if false
    /* Massage the top+shown values.  */
    if (bar->dragging == -1 || bar->last_seen_part == scroll_bar_down_arrow)
      top = max (0, min (1, top));
    else
      top = old_top;
#if ! defined (HAVE_XAW3D)
    /* With Xaw, 'top' values too closer to 1.0 may
       cause the thumb to disappear.  Fix that.  */
    top = min (top, 0.99f);
#endif
    /* Keep two pixels available for moving the thumb down.  */
    shown = max (0, min (1 - top - (2.0f / height), shown));
#if ! defined (HAVE_XAW3D)
    /* Likewise with too small 'shown'.  */
    shown = max (shown, 0.01f);
#endif
#endif

    /* If the call to XawScrollbarSetThumb below doesn't seem to
       work, check that 'NARROWPROTO' is defined in src/config.h.
       If this is not so, most likely you need to fix configure.  */
    XawScrollbarSetThumb (widget, top, shown);
#if false
    if (top != old_top || shown != old_shown)
      {
        if (bar->dragging == -1)
          XawScrollbarSetThumb (widget, top, shown);
        else
          {
            /* Try to make the scrolling a tad smoother.  */
            if (!xaw3d_pick_top)
              shown = min (shown, old_shown);

            XawScrollbarSetThumb (widget, top, shown);
          }
      }
#endif
  }
#endif /* !USE_MOTIF */

  unblock_input ();
}
#endif /* not USE_GTK */

#endif /* USE_TOOLKIT_SCROLL_BARS */


\f
/************************************************************************
                         Scroll bars, general
 ************************************************************************/

/* Create a scroll bar and return the scroll bar vector for it.  W is
   the Emacs window on which to create the scroll bar. TOP, LEFT,
   WIDTH and HEIGHT are the pixel coordinates and dimensions of the
   scroll bar. */

static struct scroll_bar *
x_scroll_bar_create (struct window *w, int top, int left,
                     int width, int height, bool horizontal)
{
  struct frame *f = XFRAME (w->frame);
  struct scroll_bar *bar
    = ALLOCATE_PSEUDOVECTOR (struct scroll_bar, x_window, PVEC_OTHER);
  Lisp_Object barobj;

  block_input ();

#ifdef USE_TOOLKIT_SCROLL_BARS
  if (horizontal)
    x_create_horizontal_toolkit_scroll_bar (f, bar);
  else
    x_create_toolkit_scroll_bar (f, bar);
#else /* not USE_TOOLKIT_SCROLL_BARS */
  {
    XSetWindowAttributes a;
    unsigned long mask;
    Window window;

    a.background_pixel = f->output_data.x->scroll_bar_background_pixel;
    if (a.background_pixel == -1)
      a.background_pixel = FRAME_BACKGROUND_PIXEL (f);

    a.event_mask = (ButtonPressMask | ButtonReleaseMask
                    | ButtonMotionMask | PointerMotionHintMask
                    | ExposureMask);
    a.cursor = FRAME_DISPLAY_INFO (f)->vertical_scroll_bar_cursor;

    mask = (CWBackPixel | CWEventMask | CWCursor);

    /* Clear the area of W that will serve as a scroll bar.  This is
       for the case that a window has been split horizontally.  In
       this case, no clear_frame is generated to reduce flickering.  */
    if (width > 0 && window_box_height (w) > 0)
      x_clear_area (f, left, top, width, window_box_height (w));

    window = XCreateWindow (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
                            /* Position and size of scroll bar.  */
                            left, top, width, height,
                            /* Border width, depth, class, and visual.  */
                            0,
                            CopyFromParent,
                            CopyFromParent,
                            CopyFromParent,
                             /* Attributes.  */
                            mask, &a);
    bar->x_window = window;
  }
#endif /* not USE_TOOLKIT_SCROLL_BARS */

  XSETWINDOW (bar->window, w);
  bar->top = top;
  bar->left = left;
  bar->width = width;
  bar->height = height;
  bar->start = 0;
  bar->end = 0;
  bar->dragging = -1;
  bar->horizontal = horizontal;
#if defined (USE_TOOLKIT_SCROLL_BARS) && defined (USE_LUCID)
  bar->last_seen_part = scroll_bar_nowhere;
#endif

  /* Add bar to its frame's list of scroll bars.  */
  bar->next = FRAME_SCROLL_BARS (f);
  bar->prev = Qnil;
  XSETVECTOR (barobj, bar);
  fset_scroll_bars (f, barobj);
  if (!NILP (bar->next))
    XSETVECTOR (XSCROLL_BAR (bar->next)->prev, bar);

  /* Map the window/widget.  */
#ifdef USE_TOOLKIT_SCROLL_BARS
  {
#ifdef USE_GTK
    if (horizontal)
      xg_update_horizontal_scrollbar_pos (f, bar->x_window, top,
                                          left, width, max (height, 1));
    else
      xg_update_scrollbar_pos (f, bar->x_window, top,
                               left, width, max (height, 1));
#else /* not USE_GTK */
    Widget scroll_bar = SCROLL_BAR_X_WIDGET (FRAME_X_DISPLAY (f), bar);
    XtConfigureWidget (scroll_bar, left, top, width, max (height, 1), 0);
    XtMapWidget (scroll_bar);
    /* Don't obscure any child frames.  */
    XLowerWindow (FRAME_X_DISPLAY (f), bar->x_window);
#endif /* not USE_GTK */
    }
#else /* not USE_TOOLKIT_SCROLL_BARS */
  XMapWindow (FRAME_X_DISPLAY (f), bar->x_window);
  /* Don't obscure any child frames.  */
  XLowerWindow (FRAME_X_DISPLAY (f), bar->x_window);
#endif /* not USE_TOOLKIT_SCROLL_BARS */

  unblock_input ();
  return bar;
}


#ifndef USE_TOOLKIT_SCROLL_BARS

/* Draw BAR's handle in the proper position.

   If the handle is already drawn from START to END, don't bother
   redrawing it, unless REBUILD; in that case, always
   redraw it.  (REBUILD is handy for drawing the handle after expose
   events.)

   Normally, we want to constrain the start and end of the handle to
   fit inside its rectangle, but if the user is dragging the scroll
   bar handle, we want to let them drag it down all the way, so that
   the bar's top is as far down as it goes; otherwise, there's no way
   to move to the very end of the buffer.  */

static void
x_scroll_bar_set_handle (struct scroll_bar *bar, int start, int end,
                         bool rebuild)
{
  bool dragging = bar->dragging != -1;
  Window w = bar->x_window;
  struct frame *f = XFRAME (WINDOW_FRAME (XWINDOW (bar->window)));
  GC gc = f->output_data.x->normal_gc;

  /* If the display is already accurate, do nothing.  */
  if (! rebuild
      && start == bar->start
      && end == bar->end)
    return;

  block_input ();

  {
    int inside_width = VERTICAL_SCROLL_BAR_INSIDE_WIDTH (f, bar->width);
    int inside_height = VERTICAL_SCROLL_BAR_INSIDE_HEIGHT (f, bar->height);
    int top_range = VERTICAL_SCROLL_BAR_TOP_RANGE (f, bar->height);

    /* Make sure the values are reasonable, and try to preserve
       the distance between start and end.  */
    {
      int length = end - start;

      if (start < 0)
        start = 0;
      else if (start > top_range)
        start = top_range;
      end = start + length;

      if (end < start)
        end = start;
      else if (end > top_range && ! dragging)
        end = top_range;
    }

    /* Store the adjusted setting in the scroll bar.  */
    bar->start = start;
    bar->end = end;

    /* Clip the end position, just for display.  */
    if (end > top_range)
      end = top_range;

    /* Draw bottom positions VERTICAL_SCROLL_BAR_MIN_HANDLE pixels
       below top positions, to make sure the handle is always at least
       that many pixels tall.  */
    end += VERTICAL_SCROLL_BAR_MIN_HANDLE;

    /* Draw the empty space above the handle.  Note that we can't clear
       zero-height areas; that means "clear to end of window."  */
    if ((inside_width > 0) && (start > 0))
      x_clear_area1 (FRAME_X_DISPLAY (f), w,
                    VERTICAL_SCROLL_BAR_LEFT_BORDER,
                    VERTICAL_SCROLL_BAR_TOP_BORDER,
                    inside_width, start, False);

    /* Change to proper foreground color if one is specified.  */
    if (f->output_data.x->scroll_bar_foreground_pixel != -1)
      XSetForeground (FRAME_X_DISPLAY (f), gc,
                      f->output_data.x->scroll_bar_foreground_pixel);

    /* Draw the handle itself.  */
    XFillRectangle (FRAME_X_DISPLAY (f), w, gc,
                    /* x, y, width, height */
                    VERTICAL_SCROLL_BAR_LEFT_BORDER,
                    VERTICAL_SCROLL_BAR_TOP_BORDER + start,
                    inside_width, end - start);

    /* Restore the foreground color of the GC if we changed it above.  */
    if (f->output_data.x->scroll_bar_foreground_pixel != -1)
      XSetForeground (FRAME_X_DISPLAY (f), gc,
                      FRAME_FOREGROUND_PIXEL (f));

    /* Draw the empty space below the handle.  Note that we can't
       clear zero-height areas; that means "clear to end of window." */
    if ((inside_width > 0) && (end < inside_height))
      x_clear_area1 (FRAME_X_DISPLAY (f), w,
                    VERTICAL_SCROLL_BAR_LEFT_BORDER,
                    VERTICAL_SCROLL_BAR_TOP_BORDER + end,
                    inside_width, inside_height - end, False);
  }

  unblock_input ();
}

#endif /* !USE_TOOLKIT_SCROLL_BARS */

/* Destroy scroll bar BAR, and set its Emacs window's scroll bar to
   nil.  */

static void
x_scroll_bar_remove (struct scroll_bar *bar)
{
  struct frame *f = XFRAME (WINDOW_FRAME (XWINDOW (bar->window)));
  block_input ();

#ifdef USE_TOOLKIT_SCROLL_BARS
#ifdef USE_GTK
  xg_remove_scroll_bar (f, bar->x_window);
#else /* not USE_GTK */
  XtDestroyWidget (SCROLL_BAR_X_WIDGET (FRAME_X_DISPLAY (f), bar));
#endif /* not USE_GTK */
#else
  XDestroyWindow (FRAME_X_DISPLAY (f), bar->x_window);
#endif

  /* Dissociate this scroll bar from its window.  */
  if (bar->horizontal)
    wset_horizontal_scroll_bar (XWINDOW (bar->window), Qnil);
  else
    wset_vertical_scroll_bar (XWINDOW (bar->window), Qnil);

  unblock_input ();
}


/* Set the handle of the vertical scroll bar for WINDOW to indicate
   that we are displaying PORTION characters out of a total of WHOLE
   characters, starting at POSITION.  If WINDOW has no scroll bar,
   create one.  */

static void
XTset_vertical_scroll_bar (struct window *w, int portion, int whole, int position)
{
  struct frame *f = XFRAME (w->frame);
  Lisp_Object barobj;
  struct scroll_bar *bar;
  int top, height, left, width;
  int window_y, window_height;

  /* Get window dimensions.  */
  window_box (w, ANY_AREA, 0, &window_y, 0, &window_height);
  top = window_y;
  height = window_height;
  left = WINDOW_SCROLL_BAR_AREA_X (w);
  width = WINDOW_SCROLL_BAR_AREA_WIDTH (w);

  /* Does the scroll bar exist yet?  */
  if (NILP (w->vertical_scroll_bar))
    {
      if (width > 0 && height > 0)
        {
          block_input ();
          x_clear_area (f, left, top, width, height);
          unblock_input ();
        }

      bar = x_scroll_bar_create (w, top, left, width, max (height, 1), false);
    }
  else
    {
      /* It may just need to be moved and resized.  */
      unsigned int mask = 0;

      bar = XSCROLL_BAR (w->vertical_scroll_bar);

      block_input ();

      if (left != bar->left)
        mask |= CWX;
      if (top != bar->top)
        mask |= CWY;
      if (width != bar->width)
        mask |= CWWidth;
      if (height != bar->height)
        mask |= CWHeight;

#ifdef USE_TOOLKIT_SCROLL_BARS

      /* Move/size the scroll bar widget.  */
      if (mask)
        {
          /* Since toolkit scroll bars are smaller than the space reserved
             for them on the frame, we have to clear "under" them.  */
          if (width > 0 && height > 0)
            x_clear_area (f, left, top, width, height);
#ifdef USE_GTK
          xg_update_scrollbar_pos (f, bar->x_window, top,
                                   left, width, max (height, 1));
#else /* not USE_GTK */
          XtConfigureWidget (SCROLL_BAR_X_WIDGET (FRAME_X_DISPLAY (f), bar),
                             left, top, width, max (height, 1), 0);
#endif /* not USE_GTK */
        }
#else /* not USE_TOOLKIT_SCROLL_BARS */

      /* Move/size the scroll bar window.  */
      if (mask)
        {
          XWindowChanges wc;

          wc.x = left;
          wc.y = top;
          wc.width = width;
          wc.height = height;
          XConfigureWindow (FRAME_X_DISPLAY (f), bar->x_window,
                            mask, &wc);
        }

#endif /* not USE_TOOLKIT_SCROLL_BARS */

      /* Remember new settings.  */
      bar->left = left;
      bar->top = top;
      bar->width = width;
      bar->height = height;

      unblock_input ();
    }

#ifdef USE_TOOLKIT_SCROLL_BARS
  x_set_toolkit_scroll_bar_thumb (bar, portion, position, whole);
#else /* not USE_TOOLKIT_SCROLL_BARS */
  /* Set the scroll bar's current state, unless we're currently being
     dragged.  */
  if (bar->dragging == -1)
    {
      int top_range = VERTICAL_SCROLL_BAR_TOP_RANGE (f, height);

      if (whole == 0)
        x_scroll_bar_set_handle (bar, 0, top_range, false);
      else
        {
          int start = ((double) position * top_range) / whole;
          int end = ((double) (position + portion) * top_range) / whole;
          x_scroll_bar_set_handle (bar, start, end, false);
        }
    }
#endif /* not USE_TOOLKIT_SCROLL_BARS */

  XSETVECTOR (barobj, bar);
  wset_vertical_scroll_bar (w, barobj);
}


static void
XTset_horizontal_scroll_bar (struct window *w, int portion, int whole, int position)
{
  struct frame *f = XFRAME (w->frame);
  Lisp_Object barobj;
  struct scroll_bar *bar;
  int top, height, left, width;
  int window_x, window_width;
  int pixel_width = WINDOW_PIXEL_WIDTH (w);

  /* Get window dimensions.  */
  window_box (w, ANY_AREA, &window_x, 0, &window_width, 0);
  left = window_x;
  width = window_width;
  top = WINDOW_SCROLL_BAR_AREA_Y (w);
  height = WINDOW_SCROLL_BAR_AREA_HEIGHT (w);

  /* Does the scroll bar exist yet?  */
  if (NILP (w->horizontal_scroll_bar))
    {
      if (width > 0 && height > 0)
        {
          block_input ();

          /* Clear also part between window_width and
             WINDOW_PIXEL_WIDTH.  */
          x_clear_area (f, left, top, pixel_width, height);
          unblock_input ();
        }

      bar = x_scroll_bar_create (w, top, left, width, height, true);
    }
  else
    {
      /* It may just need to be moved and resized.  */
      unsigned int mask = 0;

      bar = XSCROLL_BAR (w->horizontal_scroll_bar);

      block_input ();

      if (left != bar->left)
        mask |= CWX;
      if (top != bar->top)
        mask |= CWY;
      if (width != bar->width)
        mask |= CWWidth;
      if (height != bar->height)
        mask |= CWHeight;

#ifdef USE_TOOLKIT_SCROLL_BARS
      /* Move/size the scroll bar widget.  */
      if (mask)
        {
          /* Since toolkit scroll bars are smaller than the space reserved
             for them on the frame, we have to clear "under" them.  */
          if (width > 0 && height > 0)
            x_clear_area (f,
                          WINDOW_LEFT_EDGE_X (w), top,
                          pixel_width - WINDOW_RIGHT_DIVIDER_WIDTH (w), height);
#ifdef USE_GTK
          xg_update_horizontal_scrollbar_pos (f, bar->x_window, top, left,
                                              width, height);
#else /* not USE_GTK */
          XtConfigureWidget (SCROLL_BAR_X_WIDGET (FRAME_X_DISPLAY (f), bar),
                             left, top, width, height, 0);
#endif /* not USE_GTK */
        }
#else /* not USE_TOOLKIT_SCROLL_BARS */

      /* Clear areas not covered by the scroll bar because it's not as
         wide as the area reserved for it.  This makes sure a
         previous mode line display is cleared after C-x 2 C-x 1, for
         example.  */
      {
        int area_height = WINDOW_CONFIG_SCROLL_BAR_HEIGHT (w);
        int rest = area_height - height;
        if (rest > 0 && width > 0)
          x_clear_area (f, left, top, width, rest);
      }

      /* Move/size the scroll bar window.  */
      if (mask)
        {
          XWindowChanges wc;

          wc.x = left;
          wc.y = top;
          wc.width = width;
          wc.height = height;
          XConfigureWindow (FRAME_X_DISPLAY (f), bar->x_window,
                            mask, &wc);
        }

#endif /* not USE_TOOLKIT_SCROLL_BARS */

      /* Remember new settings.  */
      bar->left = left;
      bar->top = top;
      bar->width = width;
      bar->height = height;

      unblock_input ();
    }

#ifdef USE_TOOLKIT_SCROLL_BARS
  x_set_toolkit_horizontal_scroll_bar_thumb (bar, portion, position, whole);
#else /* not USE_TOOLKIT_SCROLL_BARS */
  /* Set the scroll bar's current state, unless we're currently being
     dragged.  */
  if (bar->dragging == -1)
    {
      int left_range = HORIZONTAL_SCROLL_BAR_LEFT_RANGE (f, width);

      if (whole == 0)
        x_scroll_bar_set_handle (bar, 0, left_range, false);
      else
        {
          int start = ((double) position * left_range) / whole;
          int end = ((double) (position + portion) * left_range) / whole;
          x_scroll_bar_set_handle (bar, start, end, false);
        }
    }
#endif /* not USE_TOOLKIT_SCROLL_BARS */

  XSETVECTOR (barobj, bar);
  wset_horizontal_scroll_bar (w, barobj);
}


/* The following three hooks are used when we're doing a thorough
   redisplay of the frame.  We don't explicitly know which scroll bars
   are going to be deleted, because keeping track of when windows go
   away is a real pain - "Can you say set-window-configuration, boys
   and girls?"  Instead, we just assert at the beginning of redisplay
   that *all* scroll bars are to be removed, and then save a scroll bar
   from the fiery pit when we actually redisplay its window.  */

/* Arrange for all scroll bars on FRAME to be removed at the next call
   to `*judge_scroll_bars_hook'.  A scroll bar may be spared if
   `*redeem_scroll_bar_hook' is applied to its window before the judgment.  */

static void
XTcondemn_scroll_bars (struct frame *frame)
{
  if (!NILP (FRAME_SCROLL_BARS (frame)))
    {
      if (!NILP (FRAME_CONDEMNED_SCROLL_BARS (frame)))
        {
          /* Prepend scrollbars to already condemned ones.  */
          Lisp_Object last = FRAME_SCROLL_BARS (frame);

          while (!NILP (XSCROLL_BAR (last)->next))
            last = XSCROLL_BAR (last)->next;

          XSCROLL_BAR (last)->next = FRAME_CONDEMNED_SCROLL_BARS (frame);
          XSCROLL_BAR (FRAME_CONDEMNED_SCROLL_BARS (frame))->prev = last;
        }

      fset_condemned_scroll_bars (frame, FRAME_SCROLL_BARS (frame));
      fset_scroll_bars (frame, Qnil);
    }
}


/* Un-mark WINDOW's scroll bar for deletion in this judgment cycle.
   Note that WINDOW isn't necessarily condemned at all.  */

static void
XTredeem_scroll_bar (struct window *w)
{
  struct scroll_bar *bar;
  Lisp_Object barobj;
  struct frame *f;

  /* We can't redeem this window's scroll bar if it doesn't have one.  */
  if (NILP (w->vertical_scroll_bar) && NILP (w->horizontal_scroll_bar))
    emacs_abort ();

  if (!NILP (w->vertical_scroll_bar) && WINDOW_HAS_VERTICAL_SCROLL_BAR (w))
    {
      bar = XSCROLL_BAR (w->vertical_scroll_bar);
      /* Unlink it from the condemned list.  */
      f = XFRAME (WINDOW_FRAME (w));
      if (NILP (bar->prev))
        {
          /* If the prev pointer is nil, it must be the first in one of
             the lists.  */
          if (EQ (FRAME_SCROLL_BARS (f), w->vertical_scroll_bar))
            /* It's not condemned.  Everything's fine.  */
            goto horizontal;
          else if (EQ (FRAME_CONDEMNED_SCROLL_BARS (f),
                       w->vertical_scroll_bar))
            fset_condemned_scroll_bars (f, bar->next);
          else
            /* If its prev pointer is nil, it must be at the front of
               one or the other!  */
            emacs_abort ();
        }
      else
        XSCROLL_BAR (bar->prev)->next = bar->next;

      if (! NILP (bar->next))
        XSCROLL_BAR (bar->next)->prev = bar->prev;

      bar->next = FRAME_SCROLL_BARS (f);
      bar->prev = Qnil;
      XSETVECTOR (barobj, bar);
      fset_scroll_bars (f, barobj);
      if (! NILP (bar->next))
        XSETVECTOR (XSCROLL_BAR (bar->next)->prev, bar);
    }

 horizontal:
  if (!NILP (w->horizontal_scroll_bar) && WINDOW_HAS_HORIZONTAL_SCROLL_BAR (w))
    {
      bar = XSCROLL_BAR (w->horizontal_scroll_bar);
      /* Unlink it from the condemned list.  */
      f = XFRAME (WINDOW_FRAME (w));
      if (NILP (bar->prev))
        {
          /* If the prev pointer is nil, it must be the first in one of
             the lists.  */
          if (EQ (FRAME_SCROLL_BARS (f), w->horizontal_scroll_bar))
            /* It's not condemned.  Everything's fine.  */
            return;
          else if (EQ (FRAME_CONDEMNED_SCROLL_BARS (f),
                       w->horizontal_scroll_bar))
            fset_condemned_scroll_bars (f, bar->next);
          else
            /* If its prev pointer is nil, it must be at the front of
               one or the other!  */
            emacs_abort ();
        }
      else
        XSCROLL_BAR (bar->prev)->next = bar->next;

      if (! NILP (bar->next))
        XSCROLL_BAR (bar->next)->prev = bar->prev;

      bar->next = FRAME_SCROLL_BARS (f);
      bar->prev = Qnil;
      XSETVECTOR (barobj, bar);
      fset_scroll_bars (f, barobj);
      if (! NILP (bar->next))
        XSETVECTOR (XSCROLL_BAR (bar->next)->prev, bar);
    }
}

/* Remove all scroll bars on FRAME that haven't been saved since the
   last call to `*condemn_scroll_bars_hook'.  */

static void
XTjudge_scroll_bars (struct frame *f)
{
  Lisp_Object bar, next;

  bar = FRAME_CONDEMNED_SCROLL_BARS (f);

  /* Clear out the condemned list now so we won't try to process any
     more events on the hapless scroll bars.  */
  fset_condemned_scroll_bars (f, Qnil);

  for (; ! NILP (bar); bar = next)
    {
      struct scroll_bar *b = XSCROLL_BAR (bar);

      x_scroll_bar_remove (b);

      next = b->next;
      b->next = b->prev = Qnil;
    }

  /* Now there should be no references to the condemned scroll bars,
     and they should get garbage-collected.  */
}


#ifndef USE_TOOLKIT_SCROLL_BARS
/* Handle an Expose or GraphicsExpose event on a scroll bar.  This
   is a no-op when using toolkit scroll bars.

   This may be called from a signal handler, so we have to ignore GC
   mark bits.  */

static void
x_scroll_bar_expose (struct scroll_bar *bar, const XEvent *event)
{
  Window w = bar->x_window;
  struct frame *f = XFRAME (WINDOW_FRAME (XWINDOW (bar->window)));
  GC gc = f->output_data.x->normal_gc;

  block_input ();

  x_scroll_bar_set_handle (bar, bar->start, bar->end, true);

  /* Switch to scroll bar foreground color.  */
  if (f->output_data.x->scroll_bar_foreground_pixel != -1)
    XSetForeground (FRAME_X_DISPLAY (f), gc,
                    f->output_data.x->scroll_bar_foreground_pixel);

  /* Draw a one-pixel border just inside the edges of the scroll bar.  */
  XDrawRectangle (FRAME_X_DISPLAY (f), w, gc,
                  /* x, y, width, height */
                  0, 0, bar->width - 1, bar->height - 1);

  /* Restore the foreground color of the GC if we changed it above.  */
  if (f->output_data.x->scroll_bar_foreground_pixel != -1)
    XSetForeground (FRAME_X_DISPLAY (f), gc,
                    FRAME_FOREGROUND_PIXEL (f));

   unblock_input ();

}
#endif /* not USE_TOOLKIT_SCROLL_BARS */

/* Handle a mouse click on the scroll bar BAR.  If *EMACS_EVENT's kind
   is set to something other than NO_EVENT, it is enqueued.

   This may be called from a signal handler, so we have to ignore GC
   mark bits.  */


static void
x_scroll_bar_handle_click (struct scroll_bar *bar,
                           const XEvent *event,
                           struct input_event *emacs_event)
{
  if (! WINDOWP (bar->window))
    emacs_abort ();

  emacs_event->kind = (bar->horizontal
                       ? HORIZONTAL_SCROLL_BAR_CLICK_EVENT
                       : SCROLL_BAR_CLICK_EVENT);
  emacs_event->code = event->xbutton.button - Button1;
  emacs_event->modifiers
    = (x_x_to_emacs_modifiers (FRAME_DISPLAY_INFO
                               (XFRAME (WINDOW_FRAME (XWINDOW (bar->window)))),
                               event->xbutton.state)
       | (event->type == ButtonRelease
          ? up_modifier
          : down_modifier));
  emacs_event->frame_or_window = bar->window;
  emacs_event->arg = Qnil;
  emacs_event->timestamp = event->xbutton.time;
  if (bar->horizontal)
    {
      int left_range
        = HORIZONTAL_SCROLL_BAR_LEFT_RANGE (f, bar->width);
      int x = event->xbutton.x - HORIZONTAL_SCROLL_BAR_LEFT_BORDER;

      if (x < 0) x = 0;
      if (x > left_range) x = left_range;

      if (x < bar->start)
        emacs_event->part = scroll_bar_before_handle;
      else if (x < bar->end + HORIZONTAL_SCROLL_BAR_MIN_HANDLE)
        emacs_event->part = scroll_bar_horizontal_handle;
      else
        emacs_event->part = scroll_bar_after_handle;

#ifndef USE_TOOLKIT_SCROLL_BARS
      /* If the user has released the handle, set it to its final position.  */
      if (event->type == ButtonRelease && bar->dragging != -1)
        {
          int new_start = - bar->dragging;
          int new_end = new_start + bar->end - bar->start;

          x_scroll_bar_set_handle (bar, new_start, new_end, false);
          bar->dragging = -1;
        }
#endif

      XSETINT (emacs_event->x, left_range);
      XSETINT (emacs_event->y, x);
    }
  else
    {
      int top_range
        = VERTICAL_SCROLL_BAR_TOP_RANGE (f, bar->height);
      int y = event->xbutton.y - VERTICAL_SCROLL_BAR_TOP_BORDER;

      if (y < 0) y = 0;
      if (y > top_range) y = top_range;

      if (y < bar->start)
        emacs_event->part = scroll_bar_above_handle;
      else if (y < bar->end + VERTICAL_SCROLL_BAR_MIN_HANDLE)
        emacs_event->part = scroll_bar_handle;
      else
        emacs_event->part = scroll_bar_below_handle;

#ifndef USE_TOOLKIT_SCROLL_BARS
      /* If the user has released the handle, set it to its final position.  */
      if (event->type == ButtonRelease && bar->dragging != -1)
        {
          int new_start = y - bar->dragging;
          int new_end = new_start + bar->end - bar->start;

          x_scroll_bar_set_handle (bar, new_start, new_end, false);
          bar->dragging = -1;
        }
#endif

      XSETINT (emacs_event->x, y);
      XSETINT (emacs_event->y, top_range);
    }
}

#ifndef USE_TOOLKIT_SCROLL_BARS

/* Handle some mouse motion while someone is dragging the scroll bar.

   This may be called from a signal handler, so we have to ignore GC
   mark bits.  */

static void
x_scroll_bar_note_movement (struct scroll_bar *bar,
                            const XMotionEvent *event)
{
  struct frame *f = XFRAME (XWINDOW (bar->window)->frame);
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

  dpyinfo->last_mouse_movement_time = event->time;
  dpyinfo->last_mouse_scroll_bar = bar;
  f->mouse_moved = true;

  /* If we're dragging the bar, display it.  */
  if (bar->dragging != -1)
    {
      /* Where should the handle be now?  */
      int new_start = event->y - bar->dragging;

      if (new_start != bar->start)
        {
          int new_end = new_start + bar->end - bar->start;

          x_scroll_bar_set_handle (bar, new_start, new_end, false);
        }
    }
}

#endif /* !USE_TOOLKIT_SCROLL_BARS */

/* Return information to the user about the current position of the mouse
   on the scroll bar.  */

static void
x_scroll_bar_report_motion (struct frame **fp, Lisp_Object *bar_window,
                            enum scroll_bar_part *part, Lisp_Object *x,
                            Lisp_Object *y, Time *timestamp)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (*fp);
  struct scroll_bar *bar = dpyinfo->last_mouse_scroll_bar;
  Window w = bar->x_window;
  struct frame *f = XFRAME (WINDOW_FRAME (XWINDOW (bar->window)));
  int win_x, win_y;
  Window dummy_window;
  int dummy_coord;
  unsigned int dummy_mask;

  block_input ();

  /* Get the mouse's position relative to the scroll bar window, and
     report that.  */
  if (XQueryPointer (FRAME_X_DISPLAY (f), w,

                     /* Root, child, root x and root y.  */
                     &dummy_window, &dummy_window,
                     &dummy_coord, &dummy_coord,

                     /* Position relative to scroll bar.  */
                     &win_x, &win_y,

                     /* Mouse buttons and modifier keys.  */
                     &dummy_mask))
    {
      int top_range = VERTICAL_SCROLL_BAR_TOP_RANGE (f, bar->height);

      win_y -= VERTICAL_SCROLL_BAR_TOP_BORDER;

      if (bar->dragging != -1)
        win_y -= bar->dragging;

      if (win_y < 0)
        win_y = 0;
      if (win_y > top_range)
        win_y = top_range;

      *fp = f;
      *bar_window = bar->window;

      if (bar->dragging != -1)
        *part = scroll_bar_handle;
      else if (win_y < bar->start)
        *part = scroll_bar_above_handle;
      else if (win_y < bar->end + VERTICAL_SCROLL_BAR_MIN_HANDLE)
        *part = scroll_bar_handle;
      else
        *part = scroll_bar_below_handle;

      XSETINT (*x, win_y);
      XSETINT (*y, top_range);

      f->mouse_moved = false;
      dpyinfo->last_mouse_scroll_bar = NULL;
      *timestamp = dpyinfo->last_mouse_movement_time;
    }

  unblock_input ();
}


/* Return information to the user about the current position of the mouse
   on the scroll bar.  */

static void
x_horizontal_scroll_bar_report_motion (struct frame **fp, Lisp_Object *bar_window,
                                       enum scroll_bar_part *part, Lisp_Object *x,
                                       Lisp_Object *y, Time *timestamp)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (*fp);
  struct scroll_bar *bar = dpyinfo->last_mouse_scroll_bar;
  Window w = bar->x_window;
  struct frame *f = XFRAME (WINDOW_FRAME (XWINDOW (bar->window)));
  int win_x, win_y;
  Window dummy_window;
  int dummy_coord;
  unsigned int dummy_mask;

  block_input ();

  /* Get the mouse's position relative to the scroll bar window, and
     report that.  */
  if (XQueryPointer (FRAME_X_DISPLAY (f), w,

                     /* Root, child, root x and root y.  */
                     &dummy_window, &dummy_window,
                     &dummy_coord, &dummy_coord,

                     /* Position relative to scroll bar.  */
                     &win_x, &win_y,

                     /* Mouse buttons and modifier keys.  */
                     &dummy_mask))
    {
      int left_range = HORIZONTAL_SCROLL_BAR_LEFT_RANGE (f, bar->width);

      win_x -= HORIZONTAL_SCROLL_BAR_LEFT_BORDER;

      if (bar->dragging != -1)
        win_x -= bar->dragging;

      if (win_x < 0)
        win_x = 0;
      if (win_x > left_range)
        win_x = left_range;

      *fp = f;
      *bar_window = bar->window;

      if (bar->dragging != -1)
        *part = scroll_bar_horizontal_handle;
      else if (win_x < bar->start)
        *part = scroll_bar_before_handle;
      else if (win_x < bar->end + HORIZONTAL_SCROLL_BAR_MIN_HANDLE)
        *part = scroll_bar_handle;
      else
        *part = scroll_bar_after_handle;

      XSETINT (*y, win_x);
      XSETINT (*x, left_range);

      f->mouse_moved = false;
      dpyinfo->last_mouse_scroll_bar = NULL;
      *timestamp = dpyinfo->last_mouse_movement_time;
    }

  unblock_input ();
}


/* The screen has been cleared so we may have changed foreground or
   background colors, and the scroll bars may need to be redrawn.
   Clear out the scroll bars, and ask for expose events, so we can
   redraw them.  */

static void
x_scroll_bar_clear (struct frame *f)
{
#ifndef USE_TOOLKIT_SCROLL_BARS
  Lisp_Object bar;

  /* We can have scroll bars even if this is 0,
     if we just turned off scroll bar mode.
     But in that case we should not clear them.  */
  if (FRAME_HAS_VERTICAL_SCROLL_BARS (f))
    for (bar = FRAME_SCROLL_BARS (f); VECTORP (bar);
         bar = XSCROLL_BAR (bar)->next)
      XClearArea (FRAME_X_DISPLAY (f),
                  XSCROLL_BAR (bar)->x_window,
                  0, 0, 0, 0, True);
#endif /* not USE_TOOLKIT_SCROLL_BARS */
}

#ifdef ENABLE_CHECKING

/* Record the last 100 characters stored
   to help debug the loss-of-chars-during-GC problem.  */

static int temp_index;
static short temp_buffer[100];

#define STORE_KEYSYM_FOR_DEBUG(keysym)                          \
  if (temp_index == ARRAYELTS (temp_buffer))                    \
    temp_index = 0;                                             \
  temp_buffer[temp_index++] = (keysym)

#else /* not ENABLE_CHECKING */

#define STORE_KEYSYM_FOR_DEBUG(keysym) ((void)0)

#endif /* ENABLE_CHECKING */

/* Set this to nonzero to fake an "X I/O error"
   on a particular display.  */

static struct x_display_info *XTread_socket_fake_io_error;

/* When we find no input here, we occasionally do a no-op command
   to verify that the X server is still running and we can still talk with it.
   We try all the open displays, one by one.
   This variable is used for cycling thru the displays.  */

static struct x_display_info *next_noop_dpyinfo;

enum
{
  X_EVENT_NORMAL,
  X_EVENT_GOTO_OUT,
  X_EVENT_DROP
};

/* Filter events for the current X input method.
   DPYINFO is the display this event is for.
   EVENT is the X event to filter.

   Returns non-zero if the event was filtered, caller shall not process
   this event further.
   Returns zero if event is wasn't filtered.  */

#ifdef HAVE_X_I18N
static int
x_filter_event (struct x_display_info *dpyinfo, XEvent *event)
{
  /* XFilterEvent returns non-zero if the input method has
   consumed the event.  We pass the frame's X window to
   XFilterEvent because that's the one for which the IC
   was created.  */

  struct frame *f1 = x_any_window_to_frame (dpyinfo,
                                            event->xclient.window);

  return XFilterEvent (event, f1 ? FRAME_X_WINDOW (f1) : None);
}
#endif

#ifdef USE_GTK
static int current_count;
static int current_finish;
static struct input_event *current_hold_quit;

/* This is the filter function invoked by the GTK event loop.
   It is invoked before the XEvent is translated to a GdkEvent,
   so we have a chance to act on the event before GTK.  */
static GdkFilterReturn
event_handler_gdk (GdkXEvent *gxev, GdkEvent *ev, gpointer data)
{
  XEvent *xev = (XEvent *) gxev;

  block_input ();
  if (current_count >= 0)
    {
      struct x_display_info *dpyinfo;

      dpyinfo = x_display_info_for_display (xev->xany.display);

#ifdef HAVE_X_I18N
      /* Filter events for the current X input method.
         GTK calls XFilterEvent but not for key press and release,
         so we do it here.  */
      if ((xev->type == KeyPress || xev->type == KeyRelease)
          && dpyinfo
          && x_filter_event (dpyinfo, xev))
        {
          unblock_input ();
          return GDK_FILTER_REMOVE;
        }
#endif

      if (! dpyinfo)
        current_finish = X_EVENT_NORMAL;
      else
        current_count
          += handle_one_xevent (dpyinfo, xev, &current_finish,
                                current_hold_quit);
    }
  else
    current_finish = x_dispatch_event (xev, xev->xany.display);

  unblock_input ();

  if (current_finish == X_EVENT_GOTO_OUT || current_finish == X_EVENT_DROP)
    return GDK_FILTER_REMOVE;

  return GDK_FILTER_CONTINUE;
}
#endif /* USE_GTK */


static void xembed_send_message (struct frame *f, Time,
                                 enum xembed_message,
                                 long detail, long data1, long data2);

static void
x_net_wm_state (struct frame *f, Window window)
{
  int value = FULLSCREEN_NONE;
  Lisp_Object lval = Qnil;
  bool sticky = false;

  get_current_wm_state (f, window, &value, &sticky);

  switch (value)
    {
    case FULLSCREEN_WIDTH:
      lval = Qfullwidth;
      break;
    case FULLSCREEN_HEIGHT:
      lval = Qfullheight;
      break;
    case FULLSCREEN_BOTH:
      lval = Qfullboth;
      break;
    case FULLSCREEN_MAXIMIZED:
      lval = Qmaximized;
      break;
    }

  frame_size_history_add
    (f, Qx_net_wm_state, 0, 0,
     list2 (get_frame_param (f, Qfullscreen), lval));

  store_frame_param (f, Qfullscreen, lval);
/**   store_frame_param (f, Qsticky, sticky ? Qt : Qnil); **/
}

/* Flip back buffers on any frames with undrawn content.  */
static void
flush_dirty_back_buffers (void)
{
  block_input ();
  Lisp_Object tail, frame;
  FOR_EACH_FRAME (tail, frame)
    {
      struct frame *f = XFRAME (frame);
      if (FRAME_LIVE_P (f) &&
          FRAME_X_P (f) &&
          FRAME_X_WINDOW (f) &&
          !FRAME_GARBAGED_P (f) &&
          !buffer_flipping_blocked_p () &&
          FRAME_X_NEED_BUFFER_FLIP (f))
        show_back_buffer (f);
    }
  unblock_input ();
}

/* Handles the XEvent EVENT on display DPYINFO.

   *FINISH is X_EVENT_GOTO_OUT if caller should stop reading events.
   *FINISH is zero if caller should continue reading events.
   *FINISH is X_EVENT_DROP if event should not be passed to the toolkit.
   *EVENT is unchanged unless we're processing KeyPress event.

   We return the number of characters stored into the buffer.  */

static int
handle_one_xevent (struct x_display_info *dpyinfo,
                   const XEvent *event,
                   int *finish, struct input_event *hold_quit)
{
  union buffered_input_event inev;
  int count = 0;
  int do_help = 0;
  ptrdiff_t nbytes = 0;
  struct frame *any, *f = NULL;
  struct coding_system coding;
  Mouse_HLInfo *hlinfo = &dpyinfo->mouse_highlight;
  /* This holds the state XLookupString needs to implement dead keys
     and other tricks known as "compose processing".  _X Window System_
     says that a portable program can't use this, but Stephen Gildea assures
     me that letting the compiler initialize it to zeros will work okay.  */
  static XComposeStatus compose_status;
  XEvent configureEvent;
  XEvent next_event;

  USE_SAFE_ALLOCA;

  *finish = X_EVENT_NORMAL;

  EVENT_INIT (inev.ie);
  inev.ie.kind = NO_EVENT;
  inev.ie.arg = Qnil;

  any = x_any_window_to_frame (dpyinfo, event->xany.window);

  if (any && any->wait_event_type == event->type)
    any->wait_event_type = 0; /* Indicates we got it.  */

  switch (event->type)
    {
    case ClientMessage:
      {
        if (event->xclient.message_type == dpyinfo->Xatom_wm_protocols
            && event->xclient.format == 32)
          {
            if (event->xclient.data.l[0] == dpyinfo->Xatom_wm_take_focus)
              {
                /* Use the value returned by x_any_window_to_frame
                   because this could be the shell widget window
                   if the frame has no title bar.  */
                f = any;
#ifdef HAVE_X_I18N
                /* Not quite sure this is needed -pd */
                if (f && FRAME_XIC (f))
                  XSetICFocus (FRAME_XIC (f));
#endif
#if false
      /* Emacs sets WM hints whose `input' field is `true'.  This
         instructs the WM to set the input focus automatically for
         Emacs with a call to XSetInputFocus.  Setting WM_TAKE_FOCUS
         tells the WM to send us a ClientMessage WM_TAKE_FOCUS after
         it has set the focus.  So, XSetInputFocus below is not
         needed.

         The call to XSetInputFocus below has also caused trouble.  In
         cases where the XSetInputFocus done by the WM and the one
         below are temporally close (on a fast machine), the call
         below can generate additional FocusIn events which confuse
         Emacs.  */

                /* Since we set WM_TAKE_FOCUS, we must call
                   XSetInputFocus explicitly.  But not if f is null,
                   since that might be an event for a deleted frame.  */
                if (f)
                  {
                    Display *d = event->xclient.display;
                    /* Catch and ignore errors, in case window has been
                       iconified by a window manager such as GWM.  */
                    x_catch_errors (d);
                    XSetInputFocus (d, event->xclient.window,
                                    /* The ICCCM says this is
                                       the only valid choice.  */
                                    RevertToParent,
                                    event->xclient.data.l[1]);
                    x_uncatch_errors ();
                  }
                /* Not certain about handling scroll bars here */
#endif
                goto done;
              }

            if (event->xclient.data.l[0] == dpyinfo->Xatom_wm_save_yourself)
              {
                /* Save state modify the WM_COMMAND property to
                   something which can reinstate us.  This notifies
                   the session manager, who's looking for such a
                   PropertyNotify.  Can restart processing when
                   a keyboard or mouse event arrives.  */
                /* If we have a session manager, don't set this.
                   KDE will then start two Emacsen, one for the
                   session manager and one for this. */
#ifdef HAVE_X_SM
                if (! x_session_have_connection ())
#endif
                  {
                    f = x_top_window_to_frame (dpyinfo,
                                               event->xclient.window);
                    /* This is just so we only give real data once
                       for a single Emacs process.  */
                    if (f == SELECTED_FRAME ())
                      XSetCommand (FRAME_X_DISPLAY (f),
                                   event->xclient.window,
                                   initial_argv, initial_argc);
                    else if (f)
                      XSetCommand (FRAME_X_DISPLAY (f),
                                   event->xclient.window,
                                   0, 0);
                  }
                goto done;
              }

            if (event->xclient.data.l[0] == dpyinfo->Xatom_wm_delete_window)
              {
                f = any;
                if (!f)
                  goto OTHER; /* May be a dialog that is to be removed  */

                inev.ie.kind = DELETE_WINDOW_EVENT;
                XSETFRAME (inev.ie.frame_or_window, f);
                goto done;
              }

            goto done;
          }

        if (event->xclient.message_type == dpyinfo->Xatom_wm_configure_denied)
          goto done;

        if (event->xclient.message_type == dpyinfo->Xatom_wm_window_moved)
          {
            int new_x, new_y;
            f = x_window_to_frame (dpyinfo, event->xclient.window);

            new_x = event->xclient.data.s[0];
            new_y = event->xclient.data.s[1];

            if (f)
              {
                f->left_pos = new_x;
                f->top_pos = new_y;
              }
            goto done;
          }

#ifdef X_TOOLKIT_EDITRES
        if (event->xclient.message_type == dpyinfo->Xatom_editres)
          {
            f = any;
            if (f)
              _XEditResCheckMessages (f->output_data.x->widget,
                                      NULL, (XEvent *) event, NULL);
            goto done;
          }
#endif /* X_TOOLKIT_EDITRES */

        if (event->xclient.message_type == dpyinfo->Xatom_DONE
            || event->xclient.message_type == dpyinfo->Xatom_PAGE)
          {
            /* Ghostview job completed.  Kill it.  We could
               reply with "Next" if we received "Page", but we
               currently never do because we are interested in
               images, only, which should have 1 page.  */
            Pixmap pixmap = (Pixmap) event->xclient.data.l[1];
            f = x_window_to_frame (dpyinfo, event->xclient.window);
            if (!f)
              goto OTHER;
            x_kill_gs_process (pixmap, f);
            expose_frame (f, 0, 0, 0, 0);
            goto done;
          }

#ifdef USE_TOOLKIT_SCROLL_BARS
        /* Scroll bar callbacks send a ClientMessage from which
           we construct an input_event.  */
        if (event->xclient.message_type == dpyinfo->Xatom_Scrollbar)
          {
            x_scroll_bar_to_input_event (event, &inev.ie);
            *finish = X_EVENT_GOTO_OUT;
            goto done;
          }
        else if (event->xclient.message_type == dpyinfo->Xatom_Horizontal_Scrollbar)
          {
            x_horizontal_scroll_bar_to_input_event (event, &inev.ie);
            *finish = X_EVENT_GOTO_OUT;
            goto done;
          }
#endif /* USE_TOOLKIT_SCROLL_BARS */

        /* XEmbed messages from the embedder (if any).  */
        if (event->xclient.message_type == dpyinfo->Xatom_XEMBED)
          {
            enum xembed_message msg = event->xclient.data.l[1];
            if (msg == XEMBED_FOCUS_IN || msg == XEMBED_FOCUS_OUT)
              x_detect_focus_change (dpyinfo, any, event, &inev.ie);

            *finish = X_EVENT_GOTO_OUT;
            goto done;
          }

        xft_settings_event (dpyinfo, event);

        f = any;
        if (!f)
          goto OTHER;
        if (x_handle_dnd_message (f, &event->xclient, dpyinfo, &inev.ie))
          *finish = X_EVENT_DROP;
      }
      break;

    case SelectionNotify:
      x_display_set_last_user_time (dpyinfo, event->xselection.time);
#ifdef USE_X_TOOLKIT
      if (! x_window_to_frame (dpyinfo, event->xselection.requestor))
        goto OTHER;
#endif /* not USE_X_TOOLKIT */
      x_handle_selection_notify (&event->xselection);
      break;

    case SelectionClear:        /* Someone has grabbed ownership.  */
      x_display_set_last_user_time (dpyinfo, event->xselectionclear.time);
#ifdef USE_X_TOOLKIT
      if (! x_window_to_frame (dpyinfo, event->xselectionclear.window))
        goto OTHER;
#endif /* USE_X_TOOLKIT */
      {
        const XSelectionClearEvent *eventp = &event->xselectionclear;

        inev.sie.kind = SELECTION_CLEAR_EVENT;
        SELECTION_EVENT_DPYINFO (&inev.sie) = dpyinfo;
        SELECTION_EVENT_SELECTION (&inev.sie) = eventp->selection;
        SELECTION_EVENT_TIME (&inev.sie) = eventp->time;
      }
      break;

    case SelectionRequest:      /* Someone wants our selection.  */
      x_display_set_last_user_time (dpyinfo, event->xselectionrequest.time);
#ifdef USE_X_TOOLKIT
      if (!x_window_to_frame (dpyinfo, event->xselectionrequest.owner))
        goto OTHER;
#endif /* USE_X_TOOLKIT */
      {
        const XSelectionRequestEvent *eventp = &event->xselectionrequest;

        inev.sie.kind = SELECTION_REQUEST_EVENT;
        SELECTION_EVENT_DPYINFO (&inev.sie) = dpyinfo;
        SELECTION_EVENT_REQUESTOR (&inev.sie) = eventp->requestor;
        SELECTION_EVENT_SELECTION (&inev.sie) = eventp->selection;
        SELECTION_EVENT_TARGET (&inev.sie) = eventp->target;
        SELECTION_EVENT_PROPERTY (&inev.sie) = eventp->property;
        SELECTION_EVENT_TIME (&inev.sie) = eventp->time;
      }
      break;

    case PropertyNotify:
      x_display_set_last_user_time (dpyinfo, event->xproperty.time);
      f = x_top_window_to_frame (dpyinfo, event->xproperty.window);
      if (f && event->xproperty.atom == dpyinfo->Xatom_net_wm_state)
        {
          bool not_hidden = x_handle_net_wm_state (f, &event->xproperty);
          if (not_hidden && FRAME_ICONIFIED_P (f))
            {
              /* Gnome shell does not iconify us when C-z is pressed.
                 It hides the frame.  So if our state says we aren't
                 hidden anymore, treat it as deiconified.  */
              SET_FRAME_VISIBLE (f, 1);
              SET_FRAME_ICONIFIED (f, false);
              f->output_data.x->has_been_visible = true;
              inev.ie.kind = DEICONIFY_EVENT;
              XSETFRAME (inev.ie.frame_or_window, f);
            }
          else if (! not_hidden && ! FRAME_ICONIFIED_P (f))
            {
              SET_FRAME_VISIBLE (f, 0);
              SET_FRAME_ICONIFIED (f, true);
              inev.ie.kind = ICONIFY_EVENT;
              XSETFRAME (inev.ie.frame_or_window, f);
            }
        }

      x_handle_property_notify (&event->xproperty);
      xft_settings_event (dpyinfo, event);
      goto OTHER;

    case ReparentNotify:
      f = x_top_window_to_frame (dpyinfo, event->xreparent.window);
      if (f)
        {
          /* Maybe we shouldn't set this for child frames ??  */
          f->output_data.x->parent_desc = event->xreparent.parent;
          if (!FRAME_PARENT_FRAME (f))
            x_real_positions (f, &f->left_pos, &f->top_pos);
          else
            {
              Window root;
              unsigned int dummy_uint;

              block_input ();
              XGetGeometry (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                            &root, &f->left_pos, &f->top_pos,
                            &dummy_uint, &dummy_uint, &dummy_uint, &dummy_uint);
              unblock_input ();
            }

          /* Perhaps reparented due to a WM restart.  Reset this.  */
          FRAME_DISPLAY_INFO (f)->wm_type = X_WMTYPE_UNKNOWN;
          FRAME_DISPLAY_INFO (f)->net_supported_window = 0;

          x_set_frame_alpha (f);
        }
      goto OTHER;

    case Expose:
      f = x_window_to_frame (dpyinfo, event->xexpose.window);
      if (f)
        {
          if (!FRAME_VISIBLE_P (f))
            {
              block_input ();
              SET_FRAME_VISIBLE (f, 1);
              SET_FRAME_ICONIFIED (f, false);
              if (FRAME_X_DOUBLE_BUFFERED_P (f))
                font_drop_xrender_surfaces (f);
              f->output_data.x->has_been_visible = true;
              SET_FRAME_GARBAGED (f);
              unblock_input ();
            }
          else if (FRAME_GARBAGED_P (f))
            {
#ifdef USE_GTK
              /* Go around the back buffer and manually clear the
                 window the first time we show it.  This way, we avoid
                 showing users the sanity-defying horror of whatever
                 GtkWindow is rendering beneath us.  We've garbaged
                 the frame, so we'll redraw the whole thing on next
                 redisplay anyway.  Yuck.  */
              x_clear_area1 (
                FRAME_X_DISPLAY (f),
                FRAME_X_WINDOW (f),
                event->xexpose.x, event->xexpose.y,
                event->xexpose.width, event->xexpose.height,
                0);
              x_clear_under_internal_border (f);
#endif
            }


          if (!FRAME_GARBAGED_P (f))
            {
#ifdef USE_GTK
              /* This seems to be needed for GTK 2.6 and later, see
                 http://debbugs.gnu.org/cgi/bugreport.cgi?bug=15398.  */
              x_clear_area (f,
                            event->xexpose.x, event->xexpose.y,
                            event->xexpose.width, event->xexpose.height);
#endif
              expose_frame (f, event->xexpose.x, event->xexpose.y,
                            event->xexpose.width, event->xexpose.height);
#ifdef USE_GTK
              x_clear_under_internal_border (f);
#endif
            }

          if (!FRAME_GARBAGED_P (f))
            show_back_buffer (f);
        }
      else
        {
#ifndef USE_TOOLKIT_SCROLL_BARS
          struct scroll_bar *bar;
#endif
#if defined USE_LUCID
          /* Submenus of the Lucid menu bar aren't widgets
             themselves, so there's no way to dispatch events
             to them.  Recognize this case separately.  */
          {
            Widget widget = x_window_to_menu_bar (event->xexpose.window);
            if (widget)
              xlwmenu_redisplay (widget);
          }
#endif /* USE_LUCID */

#ifdef USE_TOOLKIT_SCROLL_BARS
          /* Dispatch event to the widget.  */
          goto OTHER;
#else /* not USE_TOOLKIT_SCROLL_BARS */
          bar = x_window_to_scroll_bar (event->xexpose.display,
                                        event->xexpose.window, 2);

          if (bar)
            x_scroll_bar_expose (bar, event);
#ifdef USE_X_TOOLKIT
          else
            goto OTHER;
#endif /* USE_X_TOOLKIT */
#endif /* not USE_TOOLKIT_SCROLL_BARS */
        }
      break;

    case GraphicsExpose:        /* This occurs when an XCopyArea's
                                   source area was obscured or not
                                   available.  */
      f = x_window_to_frame (dpyinfo, event->xgraphicsexpose.drawable);
      if (f)
        {
          expose_frame (f, event->xgraphicsexpose.x,
                        event->xgraphicsexpose.y,
                        event->xgraphicsexpose.width,
                        event->xgraphicsexpose.height);
#ifdef USE_GTK
          x_clear_under_internal_border (f);
#endif
          show_back_buffer (f);
        }
#ifdef USE_X_TOOLKIT
      else
        goto OTHER;
#endif /* USE_X_TOOLKIT */
      break;

    case NoExpose:              /* This occurs when an XCopyArea's
                                   source area was completely
                                   available.  */
      break;

    case UnmapNotify:
      /* Redo the mouse-highlight after the tooltip has gone.  */
      if (event->xunmap.window == tip_window)
        {
          tip_window = 0;
          x_redo_mouse_highlight (dpyinfo);
        }

      f = x_top_window_to_frame (dpyinfo, event->xunmap.window);
      if (f)            /* F may no longer exist if
                           the frame was deleted.  */
        {
          bool visible = FRAME_VISIBLE_P (f);
          /* While a frame is unmapped, display generation is
             disabled; you don't want to spend time updating a
             display that won't ever be seen.  */
          SET_FRAME_VISIBLE (f, 0);
          /* We can't distinguish, from the event, whether the window
             has become iconified or invisible.  So assume, if it
             was previously visible, than now it is iconified.
             But x_make_frame_invisible clears both
             the visible flag and the iconified flag;
             and that way, we know the window is not iconified now.  */
          if (visible || FRAME_ICONIFIED_P (f))
            {
              SET_FRAME_ICONIFIED (f, true);
              inev.ie.kind = ICONIFY_EVENT;
              XSETFRAME (inev.ie.frame_or_window, f);
            }
        }
      goto OTHER;

    case MapNotify:
      /* We use x_top_window_to_frame because map events can
         come for sub-windows and they don't mean that the
         frame is visible.  */
      f = x_top_window_to_frame (dpyinfo, event->xmap.window);
      if (f)
        {
          bool iconified = FRAME_ICONIFIED_P (f);

          /* Check if fullscreen was specified before we where mapped the
             first time, i.e. from the command line.  */
          if (!f->output_data.x->has_been_visible)
            {

              x_check_fullscreen (f);
#ifndef USE_GTK
              /* For systems that cannot synthesize `skip_taskbar' for
                 unmapped windows do the following.  */
              if (FRAME_SKIP_TASKBAR (f))
                x_set_skip_taskbar (f, Qt, Qnil);
#endif /* Not USE_GTK */
            }

          if (!iconified)
            {
              /* The `z-group' is reset every time a frame becomes
                 invisible.  Handle this here.  */
              if (FRAME_Z_GROUP (f) == z_group_above)
                x_set_z_group (f, Qabove, Qnil);
              else if (FRAME_Z_GROUP (f) == z_group_below)
                x_set_z_group (f, Qbelow, Qnil);
            }

          SET_FRAME_VISIBLE (f, 1);
          SET_FRAME_ICONIFIED (f, false);
          f->output_data.x->has_been_visible = true;

          if (iconified)
            {
              inev.ie.kind = DEICONIFY_EVENT;
              XSETFRAME (inev.ie.frame_or_window, f);
            }
          else if (! NILP (Vframe_list) && ! NILP (XCDR (Vframe_list)))
            /* Force a redisplay sooner or later to update the
               frame titles in case this is the second frame.  */
            record_asynch_buffer_change ();
        }
      goto OTHER;

    case KeyPress:

      x_display_set_last_user_time (dpyinfo, event->xkey.time);
      ignore_next_mouse_click_timeout = 0;

#if defined (USE_X_TOOLKIT) || defined (USE_GTK)
      /* Dispatch KeyPress events when in menu.  */
      if (popup_activated ())
        goto OTHER;
#endif

      f = any;

      /* If mouse-highlight is an integer, input clears out
         mouse highlighting.  */
      if (!hlinfo->mouse_face_hidden && INTEGERP (Vmouse_highlight)
#if ! defined (USE_GTK)
          && (f == 0
              || !EQ (f->tool_bar_window, hlinfo->mouse_face_window))
#endif
          )
        {
          clear_mouse_face (hlinfo);
          hlinfo->mouse_face_hidden = true;
        }

#if defined USE_MOTIF && defined USE_TOOLKIT_SCROLL_BARS
      if (f == 0)
        {
          /* Scroll bars consume key events, but we want
             the keys to go to the scroll bar's frame.  */
          Widget widget = XtWindowToWidget (dpyinfo->display,
                                            event->xkey.window);
          if (widget && XmIsScrollBar (widget))
            {
              widget = XtParent (widget);
              f = x_any_window_to_frame (dpyinfo, XtWindow (widget));
            }
        }
#endif /* USE_MOTIF and USE_TOOLKIT_SCROLL_BARS */

      if (f != 0)
        {
          KeySym keysym, orig_keysym;
          /* al%imercury@uunet.uu.net says that making this 81
             instead of 80 fixed a bug whereby meta chars made
             his Emacs hang.

             It seems that some version of XmbLookupString has
             a bug of not returning XBufferOverflow in
             status_return even if the input is too long to
             fit in 81 bytes.  So, we must prepare sufficient
             bytes for copy_buffer.  513 bytes (256 chars for
             two-byte character set) seems to be a fairly good
             approximation.  -- 2000.8.10 handa@etl.go.jp  */
          unsigned char copy_buffer[513];
          unsigned char *copy_bufptr = copy_buffer;
          int copy_bufsiz = sizeof (copy_buffer);
          int modifiers;
          Lisp_Object coding_system = Qlatin_1;
          Lisp_Object c;
          /* Event will be modified.  */
          XKeyEvent xkey = event->xkey;

#ifdef USE_GTK
          /* Don't pass keys to GTK.  A Tab will shift focus to the
             tool bar in GTK 2.4.  Keys will still go to menus and
             dialogs because in that case popup_activated is nonzero
             (see above).  */
          *finish = X_EVENT_DROP;
#endif

          xkey.state |= x_emacs_to_x_modifiers (FRAME_DISPLAY_INFO (f),
                                                extra_keyboard_modifiers);
          modifiers = xkey.state;

          /* This will have to go some day...  */

          /* make_lispy_event turns chars into control chars.
             Don't do it here because XLookupString is too eager.  */
          xkey.state &= ~ControlMask;
          xkey.state &= ~(dpyinfo->meta_mod_mask
                          | dpyinfo->super_mod_mask
                          | dpyinfo->hyper_mod_mask
                          | dpyinfo->alt_mod_mask);

          /* In case Meta is ComposeCharacter,
             clear its status.  According to Markus Ehrnsperger
             Markus.Ehrnsperger@lehrstuhl-bross.physik.uni-muenchen.de
             this enables ComposeCharacter to work whether or
             not it is combined with Meta.  */
          if (modifiers & dpyinfo->meta_mod_mask)
            memset (&compose_status, 0, sizeof (compose_status));

#ifdef HAVE_X_I18N
          if (FRAME_XIC (f))
            {
              Status status_return;

              coding_system = Vlocale_coding_system;
              nbytes = XmbLookupString (FRAME_XIC (f),
                                        &xkey, (char *) copy_bufptr,
                                        copy_bufsiz, &keysym,
                                        &status_return);
              if (status_return == XBufferOverflow)
                {
                  copy_bufsiz = nbytes + 1;
                  copy_bufptr = alloca (copy_bufsiz);
                  nbytes = XmbLookupString (FRAME_XIC (f),
                                            &xkey, (char *) copy_bufptr,
                                            copy_bufsiz, &keysym,
                                            &status_return);
                }
              /* Xutf8LookupString is a new but already deprecated interface.  -stef  */
              if (status_return == XLookupNone)
                break;
              else if (status_return == XLookupChars)
                {
                  keysym = NoSymbol;
                  modifiers = 0;
                }
              else if (status_return != XLookupKeySym
                       && status_return != XLookupBoth)
                emacs_abort ();
            }
          else
            nbytes = XLookupString (&xkey, (char *) copy_bufptr,
                                    copy_bufsiz, &keysym,
                                    &compose_status);
#else
          nbytes = XLookupString (&xkey, (char *) copy_bufptr,
                                  copy_bufsiz, &keysym,
                                  &compose_status);
#endif

          /* If not using XIM/XIC, and a compose sequence is in progress,
             we break here.  Otherwise, chars_matched is always 0.  */
          if (compose_status.chars_matched > 0 && nbytes == 0)
            break;

          memset (&compose_status, 0, sizeof (compose_status));
          orig_keysym = keysym;

          /* Common for all keysym input events.  */
          XSETFRAME (inev.ie.frame_or_window, f);
          inev.ie.modifiers
            = x_x_to_emacs_modifiers (FRAME_DISPLAY_INFO (f), modifiers);
          inev.ie.timestamp = xkey.time;

          /* First deal with keysyms which have defined
             translations to characters.  */
          if (keysym >= 32 && keysym < 128)
            /* Avoid explicitly decoding each ASCII character.  */
            {
              inev.ie.kind = ASCII_KEYSTROKE_EVENT;
              inev.ie.code = keysym;
              goto done_keysym;
            }

          /* Keysyms directly mapped to Unicode characters.  */
          if (keysym >= 0x01000000 && keysym <= 0x0110FFFF)
            {
              if (keysym < 0x01000080)
                inev.ie.kind = ASCII_KEYSTROKE_EVENT;
              else
                inev.ie.kind = MULTIBYTE_CHAR_KEYSTROKE_EVENT;
              inev.ie.code = keysym & 0xFFFFFF;
              goto done_keysym;
            }

          /* Now non-ASCII.  */
          if (HASH_TABLE_P (Vx_keysym_table)
              && (c = Fgethash (make_number (keysym),
                                Vx_keysym_table,
                                Qnil),
                  NATNUMP (c)))
            {
              inev.ie.kind = (SINGLE_BYTE_CHAR_P (XFASTINT (c))
                              ? ASCII_KEYSTROKE_EVENT
                              : MULTIBYTE_CHAR_KEYSTROKE_EVENT);
              inev.ie.code = XFASTINT (c);
              goto done_keysym;
            }

          /* Random non-modifier sorts of keysyms.  */
          if (((keysym >= XK_BackSpace && keysym <= XK_Escape)
                        || keysym == XK_Delete
#ifdef XK_ISO_Left_Tab
                        || (keysym >= XK_ISO_Left_Tab
                            && keysym <= XK_ISO_Enter)
#endif
                        || IsCursorKey (keysym) /* 0xff50 <= x < 0xff60 */
                        || IsMiscFunctionKey (keysym) /* 0xff60 <= x < VARIES */
#ifdef HPUX
                        /* This recognizes the "extended function
                           keys".  It seems there's no cleaner way.
                           Test IsModifierKey to avoid handling
                           mode_switch incorrectly.  */
                        || (XK_Select <= keysym && keysym < XK_KP_Space)
#endif
#ifdef XK_dead_circumflex
                        || orig_keysym == XK_dead_circumflex
#endif
#ifdef XK_dead_grave
                        || orig_keysym == XK_dead_grave
#endif
#ifdef XK_dead_tilde
                        || orig_keysym == XK_dead_tilde
#endif
#ifdef XK_dead_diaeresis
                        || orig_keysym == XK_dead_diaeresis
#endif
#ifdef XK_dead_macron
                        || orig_keysym == XK_dead_macron
#endif
#ifdef XK_dead_degree
                        || orig_keysym == XK_dead_degree
#endif
#ifdef XK_dead_acute
                        || orig_keysym == XK_dead_acute
#endif
#ifdef XK_dead_cedilla
                        || orig_keysym == XK_dead_cedilla
#endif
#ifdef XK_dead_breve
                        || orig_keysym == XK_dead_breve
#endif
#ifdef XK_dead_ogonek
                        || orig_keysym == XK_dead_ogonek
#endif
#ifdef XK_dead_caron
                        || orig_keysym == XK_dead_caron
#endif
#ifdef XK_dead_doubleacute
                        || orig_keysym == XK_dead_doubleacute
#endif
#ifdef XK_dead_abovedot
                        || orig_keysym == XK_dead_abovedot
#endif
                        || IsKeypadKey (keysym) /* 0xff80 <= x < 0xffbe */
                        || IsFunctionKey (keysym) /* 0xffbe <= x < 0xffe1 */
                        /* Any "vendor-specific" key is ok.  */
                        || (orig_keysym & (1 << 28))
                        || (keysym != NoSymbol && nbytes == 0))
                       && ! (IsModifierKey (orig_keysym)
                             /* The symbols from XK_ISO_Lock
                                to XK_ISO_Last_Group_Lock
                                don't have real modifiers but
                                should be treated similarly to
                                Mode_switch by Emacs. */
#if defined XK_ISO_Lock && defined XK_ISO_Last_Group_Lock
                             || (XK_ISO_Lock <= orig_keysym
                                 && orig_keysym <= XK_ISO_Last_Group_Lock)
#endif
                             ))
            {
              STORE_KEYSYM_FOR_DEBUG (keysym);
              /* make_lispy_event will convert this to a symbolic
                 key.  */
              inev.ie.kind = NON_ASCII_KEYSTROKE_EVENT;
              inev.ie.code = keysym;
              goto done_keysym;
            }

          {     /* Raw bytes, not keysym.  */
            ptrdiff_t i;
            int nchars, len;

            for (i = 0, nchars = 0; i < nbytes; i++)
              {
                if (ASCII_CHAR_P (copy_bufptr[i]))
                  nchars++;
                STORE_KEYSYM_FOR_DEBUG (copy_bufptr[i]);
              }

            if (nchars < nbytes)
              {
                /* Decode the input data.  */

                /* The input should be decoded with `coding_system'
                   which depends on which X*LookupString function
                   we used just above and the locale.  */
                setup_coding_system (coding_system, &coding);
                coding.src_multibyte = false;
                coding.dst_multibyte = true;
                /* The input is converted to events, thus we can't
                   handle composition.  Anyway, there's no XIM that
                   gives us composition information.  */
                coding.common_flags &= ~CODING_ANNOTATION_MASK;

                SAFE_NALLOCA (coding.destination, MAX_MULTIBYTE_LENGTH,
                              nbytes);
                coding.dst_bytes = MAX_MULTIBYTE_LENGTH * nbytes;
                coding.mode |= CODING_MODE_LAST_BLOCK;
                decode_coding_c_string (&coding, copy_bufptr, nbytes, Qnil);
                nbytes = coding.produced;
                nchars = coding.produced_char;
                copy_bufptr = coding.destination;
              }

            /* Convert the input data to a sequence of
               character events.  */
            for (i = 0; i < nbytes; i += len)
              {
                int ch;
                if (nchars == nbytes)
                  ch = copy_bufptr[i], len = 1;
                else
                  ch = STRING_CHAR_AND_LENGTH (copy_bufptr + i, len);
                inev.ie.kind = (SINGLE_BYTE_CHAR_P (ch)
                                ? ASCII_KEYSTROKE_EVENT
                                : MULTIBYTE_CHAR_KEYSTROKE_EVENT);
                inev.ie.code = ch;
                kbd_buffer_store_buffered_event (&inev, hold_quit);
              }

            count += nchars;

            inev.ie.kind = NO_EVENT;  /* Already stored above.  */

            if (keysym == NoSymbol)
              break;
          }
          /* FIXME: check side effects and remove this.  */
          ((XEvent *) event)->xkey = xkey;
        }
    done_keysym:
#ifdef HAVE_X_I18N
      /* Don't dispatch this event since XtDispatchEvent calls
         XFilterEvent, and two calls in a row may freeze the
         client.  */
      break;
#else
      goto OTHER;
#endif

    case KeyRelease:
      x_display_set_last_user_time (dpyinfo, event->xkey.time);
#ifdef HAVE_X_I18N
      /* Don't dispatch this event since XtDispatchEvent calls
         XFilterEvent, and two calls in a row may freeze the
         client.  */
      break;
#else
      goto OTHER;
#endif

    case EnterNotify:
      x_display_set_last_user_time (dpyinfo, event->xcrossing.time);
      x_detect_focus_change (dpyinfo, any, event, &inev.ie);

      f = any;

      if (f && x_mouse_click_focus_ignore_position)
        ignore_next_mouse_click_timeout = event->xmotion.time + 200;

      /* EnterNotify counts as mouse movement,
         so update things that depend on mouse position.  */
      if (f && !f->output_data.x->hourglass_p)
        note_mouse_movement (f, &event->xmotion);
#ifdef USE_GTK
      /* We may get an EnterNotify on the buttons in the toolbar.  In that
         case we moved out of any highlighted area and need to note this.  */
      if (!f && dpyinfo->last_mouse_glyph_frame)
        note_mouse_movement (dpyinfo->last_mouse_glyph_frame, &event->xmotion);
#endif
      goto OTHER;

    case FocusIn:
      x_detect_focus_change (dpyinfo, any, event, &inev.ie);
      goto OTHER;

    case LeaveNotify:
      x_display_set_last_user_time (dpyinfo, event->xcrossing.time);
      x_detect_focus_change (dpyinfo, any, event, &inev.ie);

      f = x_top_window_to_frame (dpyinfo, event->xcrossing.window);
      if (f)
        {
          if (f == hlinfo->mouse_face_mouse_frame)
            {
              /* If we move outside the frame, then we're
                 certainly no longer on any text in the frame.  */
              clear_mouse_face (hlinfo);
              hlinfo->mouse_face_mouse_frame = 0;
            }

          /* Generate a nil HELP_EVENT to cancel a help-echo.
             Do it only if there's something to cancel.
             Otherwise, the startup message is cleared when
             the mouse leaves the frame.  */
          if (any_help_event_p)
            do_help = -1;
        }
#ifdef USE_GTK
      /* See comment in EnterNotify above */
      else if (dpyinfo->last_mouse_glyph_frame)
        note_mouse_movement (dpyinfo->last_mouse_glyph_frame, &event->xmotion);
#endif
      goto OTHER;

    case FocusOut:
      x_detect_focus_change (dpyinfo, any, event, &inev.ie);
      goto OTHER;

    case MotionNotify:
      {
        x_display_set_last_user_time (dpyinfo, event->xmotion.time);
        previous_help_echo_string = help_echo_string;
        help_echo_string = Qnil;

        f = (x_mouse_grabbed (dpyinfo) ? dpyinfo->last_mouse_frame
             : x_window_to_frame (dpyinfo, event->xmotion.window));

        if (hlinfo->mouse_face_hidden)
          {
            hlinfo->mouse_face_hidden = false;
            clear_mouse_face (hlinfo);
          }

#ifdef USE_GTK
        if (f && xg_event_is_for_scrollbar (f, event))
          f = 0;
#endif
        if (f)
          {
            /* Maybe generate a SELECT_WINDOW_EVENT for
               `mouse-autoselect-window' but don't let popup menus
               interfere with this (Bug#1261).  */
            if (!NILP (Vmouse_autoselect_window)
                && !popup_activated ()
                /* Don't switch if we're currently in the minibuffer.
                   This tries to work around problems where the
                   minibuffer gets unselected unexpectedly, and where
                   you then have to move your mouse all the way down to
                   the minibuffer to select it.  */
                && !MINI_WINDOW_P (XWINDOW (selected_window))
                /* With `focus-follows-mouse' non-nil create an event
                   also when the target window is on another frame.  */
                && (f == XFRAME (selected_frame)
                    || !NILP (focus_follows_mouse)))
              {
                static Lisp_Object last_mouse_window;
                Lisp_Object window = window_from_coordinates
                  (f, event->xmotion.x, event->xmotion.y, 0, false);

                /* A window will be autoselected only when it is not
                   selected now and the last mouse movement event was
                   not in it.  The remainder of the code is a bit vague
                   wrt what a "window" is.  For immediate autoselection,
                   the window is usually the entire window but for GTK
                   where the scroll bars don't count.  For delayed
                   autoselection the window is usually the window's text
                   area including the margins.  */
                if (WINDOWP (window)
                    && !EQ (window, last_mouse_window)
                    && !EQ (window, selected_window))
                  {
                    inev.ie.kind = SELECT_WINDOW_EVENT;
                    inev.ie.frame_or_window = window;
                  }

                /* Remember the last window where we saw the mouse.  */
                last_mouse_window = window;
              }

            if (!note_mouse_movement (f, &event->xmotion))
              help_echo_string = previous_help_echo_string;
          }
        else
          {
#ifndef USE_TOOLKIT_SCROLL_BARS
            struct scroll_bar *bar
              = x_window_to_scroll_bar (event->xmotion.display,
                                        event->xmotion.window, 2);

            if (bar)
              x_scroll_bar_note_movement (bar, &event->xmotion);
#endif /* USE_TOOLKIT_SCROLL_BARS */

            /* If we move outside the frame, then we're
               certainly no longer on any text in the frame.  */
            clear_mouse_face (hlinfo);
          }

        /* If the contents of the global variable help_echo_string
           has changed, generate a HELP_EVENT.  */
        if (!NILP (help_echo_string)
            || !NILP (previous_help_echo_string))
          do_help = 1;
        goto OTHER;
      }

    case ConfigureNotify:
      /* An opaque move can generate a stream of events as the window
         is dragged around.  If the connection round trip time isn't
         really short, they may come faster than we can respond to
         them, given the multiple queries we can do to check window
         manager state, translate coordinates, etc.

         So if this ConfigureNotify is immediately followed by another
         for the same window, use the info from the latest update, and
         consider the events all handled.  */
      /* Opaque resize may be trickier; ConfigureNotify events are
         mixed with Expose events for multiple windows.  */
      configureEvent = *event;
      while (XPending (dpyinfo->display))
        {
          XNextEvent (dpyinfo->display, &next_event);
          if (next_event.type != ConfigureNotify
              || next_event.xconfigure.window != event->xconfigure.window
              /* Skipping events with different sizes can lead to a
                 mispositioned mode line at initial window creation.
                 Only drop window motion events for now.  */
              || next_event.xconfigure.width != event->xconfigure.width
              || next_event.xconfigure.height != event->xconfigure.height)
            {
              XPutBackEvent (dpyinfo->display, &next_event);
              break;
            }
          else
            configureEvent = next_event;
        }

      f = x_top_window_to_frame (dpyinfo, configureEvent.xconfigure.window);
      /* Unfortunately, we need to call font_drop_xrender_surfaces for
         _all_ ConfigureNotify events, otherwise we miss some and
         flicker.  Don't try to optimize these calls by looking only
         for size changes: that's not sufficient.  We miss some
         surface invalidations and flicker.  */
      block_input ();
      if (f && FRAME_X_DOUBLE_BUFFERED_P (f))
        font_drop_xrender_surfaces (f);
      unblock_input ();
#ifdef USE_CAIRO
      if (f) x_cr_destroy_surface (f);
#endif
#ifdef USE_GTK
      if (!f
          && (f = any)
          && configureEvent.xconfigure.window == FRAME_X_WINDOW (f))
        {
          block_input ();
          if (FRAME_X_DOUBLE_BUFFERED_P (f))
            font_drop_xrender_surfaces (f);
          unblock_input ();
          xg_frame_resized (f, configureEvent.xconfigure.width,
                            configureEvent.xconfigure.height);
#ifdef USE_CAIRO
          x_cr_destroy_surface (f);
#endif
          f = 0;
        }
#endif
      if (f)
        {
          /* Don't call x_net_wm_state for the scroll bar window.
             (Bug#24963, Bug#25887)  */
          if (configureEvent.xconfigure.window == FRAME_X_WINDOW (f))
            x_net_wm_state (f, configureEvent.xconfigure.window);

#ifdef USE_X_TOOLKIT
          /* Tip frames are pure X window, set size for them.  */
          if (! NILP (tip_frame) && XFRAME (tip_frame) == f)
            {
              if (FRAME_PIXEL_HEIGHT (f) != configureEvent.xconfigure.height
                  || FRAME_PIXEL_WIDTH (f) != configureEvent.xconfigure.width)
                {
                  SET_FRAME_GARBAGED (f);
                }
              FRAME_PIXEL_HEIGHT (f) = configureEvent.xconfigure.height;
              FRAME_PIXEL_WIDTH (f) = configureEvent.xconfigure.width;
            }
#endif

#ifndef USE_X_TOOLKIT
#ifndef USE_GTK
          int width =
            FRAME_PIXEL_TO_TEXT_WIDTH (f, configureEvent.xconfigure.width);
          int height =
            FRAME_PIXEL_TO_TEXT_HEIGHT (f, configureEvent.xconfigure.height);

          /* In the toolkit version, change_frame_size
             is called by the code that handles resizing
             of the EmacsFrame widget.  */

          /* Even if the number of character rows and columns has
             not changed, the font size may have changed, so we need
             to check the pixel dimensions as well.  */
          if (width != FRAME_TEXT_WIDTH (f)
              || height != FRAME_TEXT_HEIGHT (f)
              || configureEvent.xconfigure.width != FRAME_PIXEL_WIDTH (f)
              || configureEvent.xconfigure.height != FRAME_PIXEL_HEIGHT (f))
            {
              change_frame_size (f, width, height, false, true, false, true);
              x_clear_under_internal_border (f);
              SET_FRAME_GARBAGED (f);
              cancel_mouse_face (f);
            }
#endif /* not USE_GTK */
#endif

#ifdef USE_GTK
          /* GTK creates windows but doesn't map them.
             Only get real positions when mapped.  */
          if (FRAME_GTK_OUTER_WIDGET (f)
              && gtk_widget_get_mapped (FRAME_GTK_OUTER_WIDGET (f)))
#endif
            {
              int old_left = f->left_pos;
              int old_top = f->top_pos;
              Lisp_Object frame = Qnil;

              XSETFRAME (frame, f);

              if (!FRAME_PARENT_FRAME (f))
                x_real_positions (f, &f->left_pos, &f->top_pos);
              else
                {
                  Window root;
                  unsigned int dummy_uint;

                  block_input ();
                  XGetGeometry (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                                &root, &f->left_pos, &f->top_pos,
                                &dummy_uint, &dummy_uint, &dummy_uint, &dummy_uint);
                  unblock_input ();
                }

              if (old_left != f->left_pos || old_top != f->top_pos)
                {
                  inev.ie.kind = MOVE_FRAME_EVENT;
                  XSETFRAME (inev.ie.frame_or_window, f);
                }
            }


#ifdef HAVE_X_I18N
          if (FRAME_XIC (f) && (FRAME_XIC_STYLE (f) & XIMStatusArea))
            xic_set_statusarea (f);
#endif

        }
      goto OTHER;

    case ButtonRelease:
    case ButtonPress:
      {
        /* If we decide we want to generate an event to be seen
           by the rest of Emacs, we put it here.  */
        bool tool_bar_p = false;

        memset (&compose_status, 0, sizeof (compose_status));
        dpyinfo->last_mouse_glyph_frame = NULL;
        x_display_set_last_user_time (dpyinfo, event->xbutton.time);

        if (x_mouse_grabbed (dpyinfo))
          f = dpyinfo->last_mouse_frame;
        else
          {
            f = x_window_to_frame (dpyinfo, event->xbutton.window);

            if (f && event->xbutton.type == ButtonPress
                && !popup_activated ()
                && !x_window_to_scroll_bar (event->xbutton.display,
                                            event->xbutton.window, 2)
                && !FRAME_NO_ACCEPT_FOCUS (f))
              {
                /* When clicking into a child frame or when clicking
                   into a parent frame with the child frame selected and
                   `no-accept-focus' is not set, select the clicked
                   frame.  */
                struct frame *hf = dpyinfo->x_highlight_frame;

                if (FRAME_PARENT_FRAME (f) || (hf && frame_ancestor_p (f, hf)))
                  {
                    block_input ();
                    XSetInputFocus (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                                    RevertToParent, CurrentTime);
                    if (FRAME_PARENT_FRAME (f))
                      XRaiseWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f));
                    unblock_input ();
                  }
              }
          }

#ifdef USE_GTK
        if (f && xg_event_is_for_scrollbar (f, event))
          f = 0;
#endif
        if (f)
          {
#if ! defined (USE_GTK)
            /* Is this in the tool-bar?  */
            if (WINDOWP (f->tool_bar_window)
                && WINDOW_TOTAL_LINES (XWINDOW (f->tool_bar_window)))
              {
                Lisp_Object window;
                int x = event->xbutton.x;
                int y = event->xbutton.y;

                window = window_from_coordinates (f, x, y, 0, true);
                tool_bar_p = EQ (window, f->tool_bar_window);

                if (tool_bar_p && event->xbutton.button < 4)
                  handle_tool_bar_click
                    (f, x, y, event->xbutton.type == ButtonPress,
                     x_x_to_emacs_modifiers (dpyinfo, event->xbutton.state));
              }
#endif /* !USE_GTK */

            if (!tool_bar_p)
#if defined (USE_X_TOOLKIT) || defined (USE_GTK)
              if (! popup_activated ())
#endif
                {
                  if (ignore_next_mouse_click_timeout)
                    {
                      if (event->type == ButtonPress
                          && event->xbutton.time > ignore_next_mouse_click_timeout)
                        {
                          ignore_next_mouse_click_timeout = 0;
                          construct_mouse_click (&inev.ie, &event->xbutton, f);
                        }
                      if (event->type == ButtonRelease)
                        ignore_next_mouse_click_timeout = 0;
                    }
                  else
                    construct_mouse_click (&inev.ie, &event->xbutton, f);
                }
            if (FRAME_X_EMBEDDED_P (f))
              xembed_send_message (f, event->xbutton.time,
                                   XEMBED_REQUEST_FOCUS, 0, 0, 0);
          }
        else
          {
            struct scroll_bar *bar
              = x_window_to_scroll_bar (event->xbutton.display,
                                        event->xbutton.window, 2);

#ifdef USE_TOOLKIT_SCROLL_BARS
            /* Make the "Ctrl-Mouse-2 splits window" work for toolkit
               scroll bars.  */
            if (bar && event->xbutton.state & ControlMask)
              {
                x_scroll_bar_handle_click (bar, event, &inev.ie);
                *finish = X_EVENT_DROP;
              }
#else /* not USE_TOOLKIT_SCROLL_BARS */
            if (bar)
              x_scroll_bar_handle_click (bar, event, &inev.ie);
#endif /* not USE_TOOLKIT_SCROLL_BARS */
          }

        if (event->type == ButtonPress)
          {
            dpyinfo->grabbed |= (1 << event->xbutton.button);
            dpyinfo->last_mouse_frame = f;
#if ! defined (USE_GTK)
            if (f && !tool_bar_p)
              f->last_tool_bar_item = -1;
#endif /* not USE_GTK */
          }
        else
          dpyinfo->grabbed &= ~(1 << event->xbutton.button);

        /* Ignore any mouse motion that happened before this event;
           any subsequent mouse-movement Emacs events should reflect
           only motion after the ButtonPress/Release.  */
        if (f != 0)
          f->mouse_moved = false;

#if defined (USE_X_TOOLKIT) || defined (USE_GTK)
        f = x_menubar_window_to_frame (dpyinfo, event);
        /* For a down-event in the menu bar,
           don't pass it to Xt right now.
           Instead, save it away
           and we will pass it to Xt from kbd_buffer_get_event.
           That way, we can run some Lisp code first.  */
        if (! popup_activated ()
#ifdef USE_GTK
            /* Gtk+ menus only react to the first three buttons. */
            && event->xbutton.button < 3
#endif
            && f && event->type == ButtonPress
            /* Verify the event is really within the menu bar
               and not just sent to it due to grabbing.  */
            && event->xbutton.x >= 0
            && event->xbutton.x < FRAME_PIXEL_WIDTH (f)
            && event->xbutton.y >= 0
            && event->xbutton.y < FRAME_MENUBAR_HEIGHT (f)
            && event->xbutton.same_screen)
          {
            if (!f->output_data.x->saved_menu_event)
              f->output_data.x->saved_menu_event = xmalloc (sizeof *event);
            *f->output_data.x->saved_menu_event = *event;
            inev.ie.kind = MENU_BAR_ACTIVATE_EVENT;
            XSETFRAME (inev.ie.frame_or_window, f);
            *finish = X_EVENT_DROP;
          }
        else
          goto OTHER;
#endif /* USE_X_TOOLKIT || USE_GTK */
      }
      break;

    case CirculateNotify:
      goto OTHER;

    case CirculateRequest:
      goto OTHER;

    case VisibilityNotify:
      goto OTHER;

    case MappingNotify:
      /* Someone has changed the keyboard mapping - update the
         local cache.  */
      switch (event->xmapping.request)
        {
        case MappingModifier:
          x_find_modifier_meanings (dpyinfo);
          FALLTHROUGH;
        case MappingKeyboard:
          XRefreshKeyboardMapping ((XMappingEvent *) &event->xmapping);
        }
      goto OTHER;

    case DestroyNotify:
      xft_settings_event (dpyinfo, event);
      break;

    default:
    OTHER:
#ifdef USE_X_TOOLKIT
      block_input ();
    if (*finish != X_EVENT_DROP)
      XtDispatchEvent ((XEvent *) event);
    unblock_input ();
#endif /* USE_X_TOOLKIT */
    break;
    }

 done:
  if (inev.ie.kind != NO_EVENT)
    {
      kbd_buffer_store_buffered_event (&inev, hold_quit);
      count++;
    }

  if (do_help
      && !(hold_quit && hold_quit->kind != NO_EVENT))
    {
      Lisp_Object frame;

      if (f)
        XSETFRAME (frame, f);
      else
        frame = Qnil;

      if (do_help > 0)
        {
          any_help_event_p = true;
          gen_help_event (help_echo_string, frame, help_echo_window,
                          help_echo_object, help_echo_pos);
        }
      else
        {
          help_echo_string = Qnil;
          gen_help_event (Qnil, frame, Qnil, Qnil, 0);
        }
      count++;
    }

  /* Sometimes event processing draws to the frame outside redisplay.
     To ensure that these changes become visible, draw them here.  */
  flush_dirty_back_buffers ();
  SAFE_FREE ();
  return count;
}

/* Handles the XEvent EVENT on display DISPLAY.
   This is used for event loops outside the normal event handling,
   i.e. looping while a popup menu or a dialog is posted.

   Returns the value handle_one_xevent sets in the finish argument.  */
int
x_dispatch_event (XEvent *event, Display *display)
{
  struct x_display_info *dpyinfo;
  int finish = X_EVENT_NORMAL;

  dpyinfo = x_display_info_for_display (display);

  if (dpyinfo)
    handle_one_xevent (dpyinfo, event, &finish, 0);

  return finish;
}

/* Read events coming from the X server.
   Return as soon as there are no more events to be read.

   Return the number of characters stored into the buffer,
   thus pretending to be `read' (except the characters we store
   in the keyboard buffer can be multibyte, so are not necessarily
   C chars).  */

static int
XTread_socket (struct terminal *terminal, struct input_event *hold_quit)
{
  int count = 0;
  bool event_found = false;
  struct x_display_info *dpyinfo = terminal->display_info.x;

  block_input ();

  /* For debugging, this gives a way to fake an I/O error.  */
  if (dpyinfo == XTread_socket_fake_io_error)
    {
      XTread_socket_fake_io_error = 0;
      x_io_error_quitter (dpyinfo->display);
    }

#ifndef USE_GTK
  while (XPending (dpyinfo->display))
    {
      int finish;
      XEvent event;

      XNextEvent (dpyinfo->display, &event);

#ifdef HAVE_X_I18N
      /* Filter events for the current X input method.  */
      if (x_filter_event (dpyinfo, &event))
        continue;
#endif
      event_found = true;

      count += handle_one_xevent (dpyinfo, &event, &finish, hold_quit);

      if (finish == X_EVENT_GOTO_OUT)
        break;
    }

#else /* USE_GTK */

  /* For GTK we must use the GTK event loop.  But XEvents gets passed
     to our filter function above, and then to the big event switch.
     We use a bunch of globals to communicate with our filter function,
     that is kind of ugly, but it works.

     There is no way to do one display at the time, GTK just does events
     from all displays.  */

  while (gtk_events_pending ())
    {
      current_count = count;
      current_hold_quit = hold_quit;

      gtk_main_iteration ();

      count = current_count;
      current_count = -1;
      current_hold_quit = 0;

      if (current_finish == X_EVENT_GOTO_OUT)
        break;
    }
#endif /* USE_GTK */

  /* On some systems, an X bug causes Emacs to get no more events
     when the window is destroyed.  Detect that.  (1994.)  */
  if (! event_found)
    {
      /* Emacs and the X Server eats up CPU time if XNoOp is done every time.
         One XNOOP in 100 loops will make Emacs terminate.
         B. Bretthauer, 1994 */
      x_noop_count++;
      if (x_noop_count >= 100)
        {
          x_noop_count=0;

          if (next_noop_dpyinfo == 0)
            next_noop_dpyinfo = x_display_list;

          XNoOp (next_noop_dpyinfo->display);

          /* Each time we get here, cycle through the displays now open.  */
          next_noop_dpyinfo = next_noop_dpyinfo->next;
        }
    }

  /* If the focus was just given to an auto-raising frame,
     raise it now.  FIXME: handle more than one such frame.  */
  if (dpyinfo->x_pending_autoraise_frame)
    {
      x_raise_frame (dpyinfo->x_pending_autoraise_frame);
      dpyinfo->x_pending_autoraise_frame = NULL;
    }

  unblock_input ();

  return count;
}



\f
/***********************************************************************
                             Text Cursor
 ***********************************************************************/

/* Set clipping for output in glyph row ROW.  W is the window in which
   we operate.  GC is the graphics context to set clipping in.

   ROW may be a text row or, e.g., a mode line.  Text rows must be
   clipped to the interior of the window dedicated to text display,
   mode lines must be clipped to the whole window.  */

static void
x_clip_to_row (struct window *w, struct glyph_row *row,
               enum glyph_row_area area, GC gc)
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));
  XRectangle clip_rect;
  int window_x, window_y, window_width;

  window_box (w, area, &window_x, &window_y, &window_width, 0);

  clip_rect.x = window_x;
  clip_rect.y = WINDOW_TO_FRAME_PIXEL_Y (w, max (0, row->y));
  clip_rect.y = max (clip_rect.y, window_y);
  clip_rect.width = window_width;
  clip_rect.height = row->visible_height;

  x_set_clip_rectangles (f, gc, &clip_rect, 1);
}


/* Draw a hollow box cursor on window W in glyph row ROW.  */

static void
x_draw_hollow_cursor (struct window *w, struct glyph_row *row)
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
  Display *dpy = FRAME_X_DISPLAY (f);
  int x, y, wd, h;
  XGCValues xgcv;
  struct glyph *cursor_glyph;
  GC gc;

  /* Get the glyph the cursor is on.  If we can't tell because
     the current matrix is invalid or such, give up.  */
  cursor_glyph = get_phys_cursor_glyph (w);
  if (cursor_glyph == NULL)
    return;

  /* Compute frame-relative coordinates for phys cursor.  */
  get_phys_cursor_geometry (w, row, cursor_glyph, &x, &y, &h);
  wd = w->phys_cursor_width - 1;

  /* The foreground of cursor_gc is typically the same as the normal
     background color, which can cause the cursor box to be invisible.  */
  xgcv.foreground = f->output_data.x->cursor_pixel;
  if (dpyinfo->scratch_cursor_gc)
    XChangeGC (dpy, dpyinfo->scratch_cursor_gc, GCForeground, &xgcv);
  else
    dpyinfo->scratch_cursor_gc = XCreateGC (dpy, FRAME_X_DRAWABLE (f),
                                            GCForeground, &xgcv);
  gc = dpyinfo->scratch_cursor_gc;

  /* When on R2L character, show cursor at the right edge of the
     glyph, unless the cursor box is as wide as the glyph or wider
     (the latter happens when x-stretch-cursor is non-nil).  */
  if ((cursor_glyph->resolved_level & 1) != 0
      && cursor_glyph->pixel_width > wd)
    {
      x += cursor_glyph->pixel_width - wd;
      if (wd > 0)
        wd -= 1;
    }
  /* Set clipping, draw the rectangle, and reset clipping again.  */
  x_clip_to_row (w, row, TEXT_AREA, gc);
  x_draw_rectangle (f, gc, x, y, wd, h - 1);
  x_reset_clip_rectangles (f, gc);
}


/* Draw a bar cursor on window W in glyph row ROW.

   Implementation note: One would like to draw a bar cursor with an
   angle equal to the one given by the font property XA_ITALIC_ANGLE.
   Unfortunately, I didn't find a font yet that has this property set.
   --gerd.  */

static void
x_draw_bar_cursor (struct window *w, struct glyph_row *row, int width, enum text_cursor_kinds kind)
{
  struct frame *f = XFRAME (w->frame);
  struct glyph *cursor_glyph;

  /* If cursor is out of bounds, don't draw garbage.  This can happen
     in mini-buffer windows when switching between echo area glyphs
     and mini-buffer.  */
  cursor_glyph = get_phys_cursor_glyph (w);
  if (cursor_glyph == NULL)
    return;

  /* Experimental avoidance of cursor on xwidget.  */
  if (cursor_glyph->type == XWIDGET_GLYPH)
    return;

  /* If on an image, draw like a normal cursor.  That's usually better
     visible than drawing a bar, esp. if the image is large so that
     the bar might not be in the window.  */
  if (cursor_glyph->type == IMAGE_GLYPH)
    {
      struct glyph_row *r;
      r = MATRIX_ROW (w->current_matrix, w->phys_cursor.vpos);
      draw_phys_cursor_glyph (w, r, DRAW_CURSOR);
    }
  else
    {
      Display *dpy = FRAME_X_DISPLAY (f);
      Drawable drawable = FRAME_X_DRAWABLE (f);
      GC gc = FRAME_DISPLAY_INFO (f)->scratch_cursor_gc;
      unsigned long mask = GCForeground | GCBackground | GCGraphicsExposures;
      struct face *face = FACE_FROM_ID (f, cursor_glyph->face_id);
      XGCValues xgcv;

      /* If the glyph's background equals the color we normally draw
         the bars cursor in, the bar cursor in its normal color is
         invisible.  Use the glyph's foreground color instead in this
         case, on the assumption that the glyph's colors are chosen so
         that the glyph is legible.  */
      if (face->background == f->output_data.x->cursor_pixel)
        xgcv.background = xgcv.foreground = face->foreground;
      else
        xgcv.background = xgcv.foreground = f->output_data.x->cursor_pixel;
      xgcv.graphics_exposures = False;

      if (gc)
        XChangeGC (dpy, gc, mask, &xgcv);
      else
        {
          gc = XCreateGC (dpy, drawable, mask, &xgcv);
          FRAME_DISPLAY_INFO (f)->scratch_cursor_gc = gc;
        }

      x_clip_to_row (w, row, TEXT_AREA, gc);

      if (kind == BAR_CURSOR)
        {
          int x = WINDOW_TEXT_TO_FRAME_PIXEL_X (w, w->phys_cursor.x);

          if (width < 0)
            width = FRAME_CURSOR_WIDTH (f);
          width = min (cursor_glyph->pixel_width, width);

          w->phys_cursor_width = width;

          /* If the character under cursor is R2L, draw the bar cursor
             on the right of its glyph, rather than on the left.  */
          if ((cursor_glyph->resolved_level & 1) != 0)
            x += cursor_glyph->pixel_width - width;

          x_fill_rectangle (f, gc, x,
                          WINDOW_TO_FRAME_PIXEL_Y (w, w->phys_cursor.y),
                          width, row->height);
        }
      else /* HBAR_CURSOR */
        {
          int dummy_x, dummy_y, dummy_h;
          int x = WINDOW_TEXT_TO_FRAME_PIXEL_X (w, w->phys_cursor.x);

          if (width < 0)
            width = row->height;

          width = min (row->height, width);

          get_phys_cursor_geometry (w, row, cursor_glyph, &dummy_x,
                                    &dummy_y, &dummy_h);

          if ((cursor_glyph->resolved_level & 1) != 0
              && cursor_glyph->pixel_width > w->phys_cursor_width - 1)
            x += cursor_glyph->pixel_width - w->phys_cursor_width + 1;
          x_fill_rectangle (f, gc, x,
                            WINDOW_TO_FRAME_PIXEL_Y (w, w->phys_cursor.y +
                                                     row->height - width),
                            w->phys_cursor_width - 1, width);
        }

      x_reset_clip_rectangles (f, gc);
    }
}


/* RIF: Define cursor CURSOR on frame F.  */

static void
x_define_frame_cursor (struct frame *f, Cursor cursor)
{
  if (!f->pointer_invisible
      && f->output_data.x->current_cursor != cursor)
    XDefineCursor (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), cursor);
  f->output_data.x->current_cursor = cursor;
}


/* RIF: Clear area on frame F.  */

static void
x_clear_frame_area (struct frame *f, int x, int y, int width, int height)
{
  x_clear_area (f, x, y, width, height);
}


/* RIF: Draw cursor on window W.  */

static void
x_draw_window_cursor (struct window *w, struct glyph_row *glyph_row, int x,
                      int y, enum text_cursor_kinds cursor_type,
                      int cursor_width, bool on_p, bool active_p)
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));

  if (on_p)
    {
      w->phys_cursor_type = cursor_type;
      w->phys_cursor_on_p = true;

      if (glyph_row->exact_window_width_line_p
          && (glyph_row->reversed_p
              ? (w->phys_cursor.hpos < 0)
              : (w->phys_cursor.hpos >= glyph_row->used[TEXT_AREA])))
        {
          glyph_row->cursor_in_fringe_p = true;
          draw_fringe_bitmap (w, glyph_row, glyph_row->reversed_p);
        }
      else
        {
          switch (cursor_type)
            {
            case HOLLOW_BOX_CURSOR:
              x_draw_hollow_cursor (w, glyph_row);
              break;

            case FILLED_BOX_CURSOR:
              draw_phys_cursor_glyph (w, glyph_row, DRAW_CURSOR);
              break;

            case BAR_CURSOR:
              x_draw_bar_cursor (w, glyph_row, cursor_width, BAR_CURSOR);
              break;

            case HBAR_CURSOR:
              x_draw_bar_cursor (w, glyph_row, cursor_width, HBAR_CURSOR);
              break;

            case NO_CURSOR:
              w->phys_cursor_width = 0;
              break;

            default:
              emacs_abort ();
            }
        }

#ifdef HAVE_X_I18N
      if (w == XWINDOW (f->selected_window))
        if (FRAME_XIC (f) && (FRAME_XIC_STYLE (f) & XIMPreeditPosition))
          xic_set_preeditarea (w, x, y);
#endif
    }

  XFlush (FRAME_X_DISPLAY (f));
}

\f
/* Icons.  */

/* Make the x-window of frame F use the gnu icon bitmap.  */

bool
x_bitmap_icon (struct frame *f, Lisp_Object file)
{
  ptrdiff_t bitmap_id;

  if (FRAME_X_WINDOW (f) == 0)
    return true;

  /* Free up our existing icon bitmap and mask if any.  */
  if (f->output_data.x->icon_bitmap > 0)
    x_destroy_bitmap (f, f->output_data.x->icon_bitmap);
  f->output_data.x->icon_bitmap = 0;

  if (STRINGP (file))
    {
#ifdef USE_GTK
      /* Use gtk_window_set_icon_from_file () if available,
         It's not restricted to bitmaps */
      if (xg_set_icon (f, file))
        return false;
#endif /* USE_GTK */
      bitmap_id = x_create_bitmap_from_file (f, file);
      x_create_bitmap_mask (f, bitmap_id);
    }
  else
    {
      /* Create the GNU bitmap and mask if necessary.  */
      if (FRAME_DISPLAY_INFO (f)->icon_bitmap_id < 0)
        {
          ptrdiff_t rc = -1;

#ifdef USE_GTK

          if (xg_set_icon (f, xg_default_icon_file)
              || xg_set_icon_from_xpm_data (f, gnu_xpm_bits))
            {
              FRAME_DISPLAY_INFO (f)->icon_bitmap_id = -2;
              return false;
            }

#elif defined (HAVE_XPM) && defined (HAVE_X_WINDOWS)

          rc = x_create_bitmap_from_xpm_data (f, gnu_xpm_bits);
          if (rc != -1)
            FRAME_DISPLAY_INFO (f)->icon_bitmap_id = rc;

#endif

          /* If all else fails, use the (black and white) xbm image. */
          if (rc == -1)
            {
              rc = x_create_bitmap_from_data (f, (char *) gnu_xbm_bits,
                                              gnu_xbm_width, gnu_xbm_height);
              if (rc == -1)
                return true;

              FRAME_DISPLAY_INFO (f)->icon_bitmap_id = rc;
              x_create_bitmap_mask (f, FRAME_DISPLAY_INFO (f)->icon_bitmap_id);
            }
        }

      /* The first time we create the GNU bitmap and mask,
         this increments the ref-count one extra time.
         As a result, the GNU bitmap and mask are never freed.
         That way, we don't have to worry about allocating it again.  */
      x_reference_bitmap (f, FRAME_DISPLAY_INFO (f)->icon_bitmap_id);

      bitmap_id = FRAME_DISPLAY_INFO (f)->icon_bitmap_id;
    }

  x_wm_set_icon_pixmap (f, bitmap_id);
  f->output_data.x->icon_bitmap = bitmap_id;

  return false;
}


/* Make the x-window of frame F use a rectangle with text.
   Use ICON_NAME as the text.  */

bool
x_text_icon (struct frame *f, const char *icon_name)
{
  if (FRAME_X_WINDOW (f) == 0)
    return true;

  {
    XTextProperty text;
    text.value = (unsigned char *) icon_name;
    text.encoding = XA_STRING;
    text.format = 8;
    text.nitems = strlen (icon_name);
    XSetWMIconName (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f), &text);
  }

  if (f->output_data.x->icon_bitmap > 0)
    x_destroy_bitmap (f, f->output_data.x->icon_bitmap);
  f->output_data.x->icon_bitmap = 0;
  x_wm_set_icon_pixmap (f, 0);

  return false;
}
\f
#define X_ERROR_MESSAGE_SIZE 200

/* If non-nil, this should be a string.
   It means catch X errors  and store the error message in this string.

   The reason we use a stack is that x_catch_error/x_uncatch_error can
   be called from a signal handler.
*/

struct x_error_message_stack {
  char string[X_ERROR_MESSAGE_SIZE];
  Display *dpy;
  x_special_error_handler handler;
  void *handler_data;
  struct x_error_message_stack *prev;
};
static struct x_error_message_stack *x_error_message;

/* An X error handler which stores the error message in
   *x_error_message.  This is called from x_error_handler if
   x_catch_errors is in effect.  */

static void
x_error_catcher (Display *display, XErrorEvent *event)
{
  XGetErrorText (display, event->error_code,
                 x_error_message->string,
                 X_ERROR_MESSAGE_SIZE);
  if (x_error_message->handler)
    x_error_message->handler (display, event, x_error_message->string,
                              x_error_message->handler_data);
}

/* Begin trapping X errors for display DPY.  Actually we trap X errors
   for all displays, but DPY should be the display you are actually
   operating on.

   After calling this function, X protocol errors no longer cause
   Emacs to exit; instead, they are recorded in the string
   stored in *x_error_message.

   Calling x_check_errors signals an Emacs error if an X error has
   occurred since the last call to x_catch_errors or x_check_errors.

   Calling x_uncatch_errors resumes the normal error handling.
   Calling x_uncatch_errors_after_check is similar, but skips an XSync
   to the server, and should be used only immediately after
   x_had_errors_p or x_check_errors.  */

void
x_catch_errors_with_handler (Display *dpy, x_special_error_handler handler,
                             void *handler_data)
{
  struct x_error_message_stack *data = xmalloc (sizeof *data);

  /* Make sure any errors from previous requests have been dealt with.  */
  XSync (dpy, False);

  data->dpy = dpy;
  data->string[0] = 0;
  data->handler = handler;
  data->handler_data = handler_data;
  data->prev = x_error_message;
  x_error_message = data;
}

void
x_catch_errors (Display *dpy)
{
  x_catch_errors_with_handler (dpy, NULL, NULL);
}

/* Undo the last x_catch_errors call.
   DPY should be the display that was passed to x_catch_errors.

   This version should be used only if the immediately preceding
   X-protocol-related thing was x_check_errors or x_had_error_p, both
   of which issue XSync calls, so we don't need to re-sync here.  */

void
x_uncatch_errors_after_check (void)
{
  struct x_error_message_stack *tmp;

  block_input ();
  tmp = x_error_message;
  x_error_message = x_error_message->prev;
  xfree (tmp);
  unblock_input ();
}

/* Undo the last x_catch_errors call.
   DPY should be the display that was passed to x_catch_errors.  */

void
x_uncatch_errors (void)
{
  struct x_error_message_stack *tmp;

  block_input ();

  /* The display may have been closed before this function is called.
     Check if it is still open before calling XSync.  */
  if (x_display_info_for_display (x_error_message->dpy) != 0)
    XSync (x_error_message->dpy, False);

  tmp = x_error_message;
  x_error_message = x_error_message->prev;
  xfree (tmp);
  unblock_input ();
}

/* If any X protocol errors have arrived since the last call to
   x_catch_errors or x_check_errors, signal an Emacs error using
   sprintf (a buffer, FORMAT, the x error message text) as the text.  */

void
x_check_errors (Display *dpy, const char *format)
{
  /* Make sure to catch any errors incurred so far.  */
  XSync (dpy, False);

  if (x_error_message->string[0])
    {
      char string[X_ERROR_MESSAGE_SIZE];
      memcpy (string, x_error_message->string, X_ERROR_MESSAGE_SIZE);
      x_uncatch_errors ();
      error (format, string);
    }
}

/* Nonzero if we had any X protocol errors
   since we did x_catch_errors on DPY.  */

bool
x_had_errors_p (Display *dpy)
{
  /* Make sure to catch any errors incurred so far.  */
  XSync (dpy, False);

  return x_error_message->string[0] != 0;
}

/* Forget about any errors we have had, since we did x_catch_errors on DPY.  */

void
x_clear_errors (Display *dpy)
{
  x_error_message->string[0] = 0;
}

#if false
      /* See comment in unwind_to_catch why calling this is a bad
       * idea.  --lorentey   */
/* Close off all unclosed x_catch_errors calls.  */

void
x_fully_uncatch_errors (void)
{
  while (x_error_message)
    x_uncatch_errors ();
}
#endif

#if false
static unsigned int x_wire_count;
x_trace_wire (void)
{
  fprintf (stderr, "Lib call: %d\n", ++x_wire_count);
}
#endif

\f
/************************************************************************
                          Handling X errors
 ************************************************************************/

/* Error message passed to x_connection_closed.  */

static char *error_msg;

/* Handle the loss of connection to display DPY.  ERROR_MESSAGE is
   the text of an error message that lead to the connection loss.  */

static _Noreturn void
x_connection_closed (Display *dpy, const char *error_message, bool ioerror)
{
  struct x_display_info *dpyinfo = x_display_info_for_display (dpy);
  Lisp_Object frame, tail;
  ptrdiff_t idx = SPECPDL_INDEX ();

  error_msg = alloca (strlen (error_message) + 1);
  strcpy (error_msg, error_message);

  /* Inhibit redisplay while frames are being deleted. */
  specbind (Qinhibit_redisplay, Qt);

  if (dpyinfo)
    {
      /* Protect display from being closed when we delete the last
         frame on it. */
      dpyinfo->reference_count++;
      dpyinfo->terminal->reference_count++;
    }
  if (ioerror) dpyinfo->display = 0;

  /* First delete frames whose mini-buffers are on frames
     that are on the dead display.  */
  FOR_EACH_FRAME (tail, frame)
    {
      Lisp_Object minibuf_frame;
      minibuf_frame
        = WINDOW_FRAME (XWINDOW (FRAME_MINIBUF_WINDOW (XFRAME (frame))));
      if (FRAME_X_P (XFRAME (frame))
          && FRAME_X_P (XFRAME (minibuf_frame))
          && ! EQ (frame, minibuf_frame)
          && FRAME_DISPLAY_INFO (XFRAME (minibuf_frame)) == dpyinfo)
        delete_frame (frame, Qnoelisp);
    }

  /* Now delete all remaining frames on the dead display.
     We are now sure none of these is used as the mini-buffer
     for another frame that we need to delete.  */
  FOR_EACH_FRAME (tail, frame)
    if (FRAME_X_P (XFRAME (frame))
        && FRAME_DISPLAY_INFO (XFRAME (frame)) == dpyinfo)
      {
        /* Set this to t so that delete_frame won't get confused
           trying to find a replacement.  */
        kset_default_minibuffer_frame (FRAME_KBOARD (XFRAME (frame)), Qt);
        delete_frame (frame, Qnoelisp);
      }

  /* If DPYINFO is null, this means we didn't open the display in the
     first place, so don't try to close it.  */
  if (dpyinfo)
    {
      /* We can not call XtCloseDisplay here because it calls XSync.
         XSync inside the error handler apparently hangs Emacs.  On
         current Xt versions, this isn't needed either.  */
#ifdef USE_GTK
      /* A long-standing GTK bug prevents proper disconnect handling
         (https://bugzilla.gnome.org/show_bug.cgi?id=85715).  Once,
         the resulting Glib error message loop filled a user's disk.
         To avoid this, kill Emacs unconditionally on disconnect.  */
      shut_down_emacs (0, Qnil);
      fprintf (stderr, "%s\n\
When compiled with GTK, Emacs cannot recover from X disconnects.\n\
This is a GTK bug: https://bugzilla.gnome.org/show_bug.cgi?id=85715\n\
For details, see etc/PROBLEMS.\n",
               error_msg);
      emacs_abort ();
#endif /* USE_GTK */

      /* Indicate that this display is dead.  */
      dpyinfo->display = 0;

      dpyinfo->reference_count--;
      dpyinfo->terminal->reference_count--;
      if (dpyinfo->reference_count != 0)
        /* We have just closed all frames on this display. */
        emacs_abort ();

      {
        Lisp_Object tmp;
        XSETTERMINAL (tmp, dpyinfo->terminal);
        Fdelete_terminal (tmp, Qnoelisp);
      }
    }

  if (terminal_list == 0)
    {
      fprintf (stderr, "%s\n", error_msg);
      Fkill_emacs (make_number (70));
      /* NOTREACHED */
    }

  totally_unblock_input ();

  unbind_to (idx, Qnil);
  clear_waiting_for_input ();

  /* Here, we absolutely have to use a non-local exit (e.g. signal, throw,
     longjmp), because returning from this function would get us back into
     Xlib's code which will directly call `exit'.  */
  error ("%s", error_msg);
}

/* We specifically use it before defining it, so that gcc doesn't inline it,
   otherwise gdb doesn't know how to properly put a breakpoint on it.  */
static void x_error_quitter (Display *, XErrorEvent *);

/* This is the first-level handler for X protocol errors.
   It calls x_error_quitter or x_error_catcher.  */

static int
x_error_handler (Display *display, XErrorEvent *event)
{
#if defined USE_GTK && defined HAVE_GTK3
  if ((event->error_code == BadMatch || event->error_code == BadWindow)
      && event->request_code == X_SetInputFocus)
    {
      return 0;
    }
#endif

  if (x_error_message)
    x_error_catcher (display, event);
  else
    x_error_quitter (display, event);
  return 0;
}

/* This is the usual handler for X protocol errors.
   It kills all frames on the display that we got the error for.
   If that was the only one, it prints an error message and kills Emacs.  */

/* .gdbinit puts a breakpoint here, so make sure it is not inlined.  */

/* On older GCC versions, just putting x_error_quitter
   after x_error_handler prevents inlining into the former.  */

static void NO_INLINE
x_error_quitter (Display *display, XErrorEvent *event)
{
  char buf[256], buf1[356];

  /* Ignore BadName errors.  They can happen because of fonts
     or colors that are not defined.  */

  if (event->error_code == BadName)
    return;

  /* Note that there is no real way portable across R3/R4 to get the
     original error handler.  */

  XGetErrorText (display, event->error_code, buf, sizeof (buf));
  sprintf (buf1, "X protocol error: %s on protocol request %d",
           buf, event->request_code);
  x_connection_closed (display, buf1, false);
}


/* This is the handler for X IO errors, always.
   It kills all frames on the display that we lost touch with.
   If that was the only one, it prints an error message and kills Emacs.  */

static _Noreturn int
x_io_error_quitter (Display *display)
{
  char buf[256];

  snprintf (buf, sizeof buf, "Connection lost to X server '%s'",
            DisplayString (display));
  x_connection_closed (display, buf, true);
  assume (false);
}
\f
/* Changing the font of the frame.  */

/* Give frame F the font FONT-OBJECT as its default font.  The return
   value is FONT-OBJECT.  FONTSET is an ID of the fontset for the
   frame.  If it is negative, generate a new fontset from
   FONT-OBJECT.  */

Lisp_Object
x_new_font (struct frame *f, Lisp_Object font_object, int fontset)
{
  struct font *font = XFONT_OBJECT (font_object);
  int unit, font_ascent, font_descent;
#ifndef USE_X_TOOLKIT
  int old_menu_bar_height = FRAME_MENU_BAR_HEIGHT (f);
  Lisp_Object fullscreen;
#endif

  if (fontset < 0)
    fontset = fontset_from_font (font_object);
  FRAME_FONTSET (f) = fontset;
  if (FRAME_FONT (f) == font)
    /* This font is already set in frame F.  There's nothing more to
       do.  */
    return font_object;

  FRAME_FONT (f) = font;
  FRAME_BASELINE_OFFSET (f) = font->baseline_offset;
  FRAME_COLUMN_WIDTH (f) = font->average_width;
  get_font_ascent_descent (font, &font_ascent, &font_descent);
  FRAME_LINE_HEIGHT (f) = font_ascent + font_descent;

#ifndef USE_X_TOOLKIT
  FRAME_MENU_BAR_HEIGHT (f) = FRAME_MENU_BAR_LINES (f) * FRAME_LINE_HEIGHT (f);
#endif

  /* Compute character columns occupied by scrollbar.

     Don't do things differently for non-toolkit scrollbars
     (Bug#17163).  */
  unit = FRAME_COLUMN_WIDTH (f);
  if (FRAME_CONFIG_SCROLL_BAR_WIDTH (f) > 0)
    FRAME_CONFIG_SCROLL_BAR_COLS (f)
      = (FRAME_CONFIG_SCROLL_BAR_WIDTH (f) + unit - 1) / unit;
  else
    FRAME_CONFIG_SCROLL_BAR_COLS (f) = (14 + unit - 1) / unit;

  if (FRAME_X_WINDOW (f) != 0)
    {
      /* Don't change the size of a tip frame; there's no point in
         doing it because it's done in Fx_show_tip, and it leads to
         problems because the tip frame has no widget.  */
      if (NILP (tip_frame) || XFRAME (tip_frame) != f)
        {
          adjust_frame_size (f, FRAME_COLS (f) * FRAME_COLUMN_WIDTH (f),
                             FRAME_LINES (f) * FRAME_LINE_HEIGHT (f), 3,
                             false, Qfont);
#ifndef USE_X_TOOLKIT
          if (FRAME_MENU_BAR_HEIGHT (f) != old_menu_bar_height
              && !f->after_make_frame
              && (EQ (frame_inhibit_implied_resize, Qt)
                  || (CONSP (frame_inhibit_implied_resize)
                      && NILP (Fmemq (Qfont, frame_inhibit_implied_resize))))
              && (NILP (fullscreen = get_frame_param (f, Qfullscreen))
                  || EQ (fullscreen, Qfullwidth)))
            /* If the menu bar height changes, try to keep text height
               constant.  */
            adjust_frame_size
              (f, -1, FRAME_TEXT_HEIGHT (f) + FRAME_MENU_BAR_HEIGHT (f)
               - old_menu_bar_height, 1, false, Qfont);
#endif /* USE_X_TOOLKIT  */
        }
    }

#ifdef HAVE_X_I18N
  if (FRAME_XIC (f)
      && (FRAME_XIC_STYLE (f) & (XIMPreeditPosition | XIMStatusArea)))
    {
      block_input ();
      xic_set_xfontset (f, SSDATA (fontset_ascii (fontset)));
      unblock_input ();
    }
#endif

  return font_object;
}

\f
/***********************************************************************
                           X Input Methods
 ***********************************************************************/

#ifdef HAVE_X_I18N

#ifdef HAVE_X11R6

/* XIM destroy callback function, which is called whenever the
   connection to input method XIM dies.  CLIENT_DATA contains a
   pointer to the x_display_info structure corresponding to XIM.  */

static void
xim_destroy_callback (XIM xim, XPointer client_data, XPointer call_data)
{
  struct x_display_info *dpyinfo = (struct x_display_info *) client_data;
  Lisp_Object frame, tail;

  block_input ();

  /* No need to call XDestroyIC.. */
  FOR_EACH_FRAME (tail, frame)
    {
      struct frame *f = XFRAME (frame);
      if (FRAME_X_P (f) && FRAME_DISPLAY_INFO (f) == dpyinfo)
        {
          FRAME_XIC (f) = NULL;
          xic_free_xfontset (f);
        }
    }

  /* No need to call XCloseIM.  */
  dpyinfo->xim = NULL;
  XFree (dpyinfo->xim_styles);
  unblock_input ();
}

#endif /* HAVE_X11R6 */

/* Open the connection to the XIM server on display DPYINFO.
   RESOURCE_NAME is the resource name Emacs uses.  */

static void
xim_open_dpy (struct x_display_info *dpyinfo, char *resource_name)
{
  XIM xim;

#ifdef HAVE_XIM
  if (use_xim)
    {
      if (dpyinfo->xim)
        XCloseIM (dpyinfo->xim);
      xim = XOpenIM (dpyinfo->display, dpyinfo->xrdb, resource_name,
                     emacs_class);
      dpyinfo->xim = xim;

      if (xim)
        {
#ifdef HAVE_X11R6
          XIMCallback destroy;
#endif

          /* Get supported styles and XIM values.  */
          XGetIMValues (xim, XNQueryInputStyle, &dpyinfo->xim_styles, NULL);

#ifdef HAVE_X11R6
          destroy.callback = xim_destroy_callback;
          destroy.client_data = (XPointer)dpyinfo;
          XSetIMValues (xim, XNDestroyCallback, &destroy, NULL);
#endif
        }
    }

  else
#endif /* HAVE_XIM */
    dpyinfo->xim = NULL;
}


#ifdef HAVE_X11R6_XIM

/* XIM instantiate callback function, which is called whenever an XIM
   server is available.  DISPLAY is the display of the XIM.
   CLIENT_DATA contains a pointer to an xim_inst_t structure created
   when the callback was registered.  */

static void
xim_instantiate_callback (Display *display, XPointer client_data, XPointer call_data)
{
  struct xim_inst_t *xim_inst = (struct xim_inst_t *) client_data;
  struct x_display_info *dpyinfo = xim_inst->dpyinfo;

  /* We don't support multiple XIM connections. */
  if (dpyinfo->xim)
    return;

  xim_open_dpy (dpyinfo, xim_inst->resource_name);

  /* Create XIC for the existing frames on the same display, as long
     as they have no XIC.  */
  if (dpyinfo->xim && dpyinfo->reference_count > 0)
    {
      Lisp_Object tail, frame;

      block_input ();
      FOR_EACH_FRAME (tail, frame)
        {
          struct frame *f = XFRAME (frame);

          if (FRAME_X_P (f)
              && FRAME_DISPLAY_INFO (f) == xim_inst->dpyinfo)
            if (FRAME_XIC (f) == NULL)
              {
                create_frame_xic (f);
                if (FRAME_XIC_STYLE (f) & XIMStatusArea)
                  xic_set_statusarea (f);
                if (FRAME_XIC_STYLE (f) & XIMPreeditPosition)
                  {
                    struct window *w = XWINDOW (f->selected_window);
                    xic_set_preeditarea (w, w->cursor.x, w->cursor.y);
                  }
              }
        }

      unblock_input ();
    }
}

#endif /* HAVE_X11R6_XIM */


/* Open a connection to the XIM server on display DPYINFO.
   RESOURCE_NAME is the resource name for Emacs.  On X11R5, open the
   connection only at the first time.  On X11R6, open the connection
   in the XIM instantiate callback function.  */

static void
xim_initialize (struct x_display_info *dpyinfo, char *resource_name)
{
  dpyinfo->xim = NULL;
#ifdef HAVE_XIM
  if (use_xim)
    {
#ifdef HAVE_X11R6_XIM
      struct xim_inst_t *xim_inst = xmalloc (sizeof *xim_inst);
      Bool ret;

      dpyinfo->xim_callback_data = xim_inst;
      xim_inst->dpyinfo = dpyinfo;
      xim_inst->resource_name = xstrdup (resource_name);
      ret = XRegisterIMInstantiateCallback
        (dpyinfo->display, dpyinfo->xrdb, xim_inst->resource_name,
         emacs_class, xim_instantiate_callback,
         /* This is XPointer in XFree86 but (XPointer *)
            on Tru64, at least, hence the configure test.  */
         (XRegisterIMInstantiateCallback_arg6) xim_inst);
      eassert (ret == True);
#else /* not HAVE_X11R6_XIM */
      xim_open_dpy (dpyinfo, resource_name);
#endif /* not HAVE_X11R6_XIM */
    }
#endif /* HAVE_XIM */
}


/* Close the connection to the XIM server on display DPYINFO. */

static void
xim_close_dpy (struct x_display_info *dpyinfo)
{
#ifdef HAVE_XIM
  if (use_xim)
    {
#ifdef HAVE_X11R6_XIM
      struct xim_inst_t *xim_inst = dpyinfo->xim_callback_data;

      if (dpyinfo->display)
        {
          Bool ret = XUnregisterIMInstantiateCallback
            (dpyinfo->display, dpyinfo->xrdb, xim_inst->resource_name,
             emacs_class, xim_instantiate_callback,
             (XRegisterIMInstantiateCallback_arg6) xim_inst);
          eassert (ret == True);
        }
      xfree (xim_inst->resource_name);
      xfree (xim_inst);
#endif /* HAVE_X11R6_XIM */
      if (dpyinfo->display)
        XCloseIM (dpyinfo->xim);
      dpyinfo->xim = NULL;
      XFree (dpyinfo->xim_styles);
    }
#endif /* HAVE_XIM */
}

#endif /* not HAVE_X11R6_XIM */


\f
/* Calculate the absolute position in frame F
   from its current recorded position values and gravity.  */

static void
x_calc_absolute_position (struct frame *f)
{
  int flags = f->size_hint_flags;
  struct frame *p = FRAME_PARENT_FRAME (f);

  /* We have nothing to do if the current position
     is already for the top-left corner.  */
  if (! ((flags & XNegative) || (flags & YNegative)))
    return;

  /* Treat negative positions as relative to the leftmost bottommost
     position that fits on the screen.  */
  if ((flags & XNegative) && (f->left_pos <= 0))
    {
      int width = FRAME_PIXEL_WIDTH (f);

      /* A frame that has been visible at least once should have outer
         edges.  */
      if (f->output_data.x->has_been_visible && !p)
        {
          Lisp_Object frame;
          Lisp_Object edges = Qnil;

          XSETFRAME (frame, f);
          edges = Fx_frame_edges (frame, Qouter_edges);
          if (!NILP (edges))
            width = (XINT (Fnth (make_number (2), edges))
                     - XINT (Fnth (make_number (0), edges)));
        }

      if (p)
        f->left_pos = (FRAME_PIXEL_WIDTH (p) - width - 2 * f->border_width
                       + f->left_pos);
      else
        f->left_pos = (x_display_pixel_width (FRAME_DISPLAY_INFO (f))
                       - width + f->left_pos);

    }

  if ((flags & YNegative) && (f->top_pos <= 0))
    {
      int height = FRAME_PIXEL_HEIGHT (f);

#if defined USE_X_TOOLKIT && defined USE_MOTIF
      /* Something is fishy here.  When using Motif, starting Emacs with
         `-g -0-0', the frame appears too low by a few pixels.

         This seems to be so because initially, while Emacs is starting,
         the column widget's height and the frame's pixel height are
         different.  The column widget's height is the right one.  In
         later invocations, when Emacs is up, the frame's pixel height
         is right, though.

         It's not obvious where the initial small difference comes from.
         2000-12-01, gerd.  */

      XtVaGetValues (f->output_data.x->column_widget, XtNheight, &height, NULL);
#endif

      if (f->output_data.x->has_been_visible && !p)
        {
          Lisp_Object frame;
          Lisp_Object edges = Qnil;

          XSETFRAME (frame, f);
          if (NILP (edges))
            edges = Fx_frame_edges (frame, Qouter_edges);
          if (!NILP (edges))
            height = (XINT (Fnth (make_number (3), edges))
                      - XINT (Fnth (make_number (1), edges)));
        }

      if (p)
        f->top_pos = (FRAME_PIXEL_HEIGHT (p) - height - 2 * f->border_width
                       + f->top_pos);
      else
        f->top_pos = (x_display_pixel_height (FRAME_DISPLAY_INFO (f))
                      - height + f->top_pos);
  }

  /* The left_pos and top_pos
     are now relative to the top and left screen edges,
     so the flags should correspond.  */
  f->size_hint_flags &= ~ (XNegative | YNegative);
}

/* CHANGE_GRAVITY is 1 when calling from Fset_frame_position,
   to really change the position, and 0 when calling from
   x_make_frame_visible (in that case, XOFF and YOFF are the current
   position values).  It is -1 when calling from x_set_frame_parameters,
   which means, do adjust for borders but don't change the gravity.  */

void
x_set_offset (struct frame *f, register int xoff, register int yoff, int change_gravity)
{
  int modified_top, modified_left;

  if (change_gravity > 0)
    {
      f->top_pos = yoff;
      f->left_pos = xoff;
      f->size_hint_flags &= ~ (XNegative | YNegative);
      if (xoff < 0)
        f->size_hint_flags |= XNegative;
      if (yoff < 0)
        f->size_hint_flags |= YNegative;
      f->win_gravity = NorthWestGravity;
    }

  x_calc_absolute_position (f);

  block_input ();
  x_wm_set_size_hint (f, 0, false);

#ifdef USE_GTK
  if (x_gtk_use_window_move)
    {
      /* When a position change was requested and the outer GTK widget
         has been realized already, leave it to gtk_window_move to DTRT
         and return.  Used for Bug#25851 and Bug#25943.  */
      if (change_gravity != 0 && FRAME_GTK_OUTER_WIDGET (f))
        gtk_window_move (GTK_WINDOW (FRAME_GTK_OUTER_WIDGET (f)),
                         f->left_pos, f->top_pos);
      unblock_input ();
      return;
    }
#endif /* USE_GTK */

  modified_left = f->left_pos;
  modified_top = f->top_pos;

  if (change_gravity != 0 && FRAME_DISPLAY_INFO (f)->wm_type == X_WMTYPE_A)
    {
      /* Some WMs (twm, wmaker at least) has an offset that is smaller
         than the WM decorations.  So we use the calculated offset instead
         of the WM decoration sizes here (x/y_pixels_outer_diff).  */
      modified_left += FRAME_X_OUTPUT (f)->move_offset_left;
      modified_top += FRAME_X_OUTPUT (f)->move_offset_top;
    }

#ifdef USE_GTK
  gtk_window_move (GTK_WINDOW (FRAME_GTK_OUTER_WIDGET (f)),
                   modified_left, modified_top);
#else
  XMoveWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
               modified_left, modified_top);
#endif

  x_sync_with_move (f, f->left_pos, f->top_pos,
                    FRAME_DISPLAY_INFO (f)->wm_type == X_WMTYPE_UNKNOWN);

  /* change_gravity is non-zero when this function is called from Lisp to
     programmatically move a frame.  In that case, we call
     x_check_expected_move to discover if we have a "Type A" or "Type B"
     window manager, and, for a "Type A" window manager, adjust the position
     of the frame.

     We call x_check_expected_move if a programmatic move occurred, and
     either the window manager type (A/B) is unknown or it is Type A but we
     need to compute the top/left offset adjustment for this frame.  */

  if (change_gravity != 0
      && !FRAME_PARENT_FRAME (f)
      && (FRAME_DISPLAY_INFO (f)->wm_type == X_WMTYPE_UNKNOWN
          || (FRAME_DISPLAY_INFO (f)->wm_type == X_WMTYPE_A
              && (FRAME_X_OUTPUT (f)->move_offset_left == 0
                  && FRAME_X_OUTPUT (f)->move_offset_top == 0))))
    x_check_expected_move (f, modified_left, modified_top);

  unblock_input ();
}

/* Return true if _NET_SUPPORTING_WM_CHECK window exists and _NET_SUPPORTED
   on the root window for frame F contains ATOMNAME.
   This is how a WM check shall be done according to the Window Manager
   Specification/Extended Window Manager Hints at
   http://freedesktop.org/wiki/Specifications/wm-spec.  */

bool
x_wm_supports (struct frame *f, Atom want_atom)
{
  Atom actual_type;
  unsigned long actual_size, bytes_remaining;
  int i, rc, actual_format;
  bool ret;
  Window wmcheck_window;
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
  Window target_window = dpyinfo->root_window;
  int max_len = 65536;
  Display *dpy = FRAME_X_DISPLAY (f);
  unsigned char *tmp_data = NULL;
  Atom target_type = XA_WINDOW;

  block_input ();

  x_catch_errors (dpy);
  rc = XGetWindowProperty (dpy, target_window,
                           dpyinfo->Xatom_net_supporting_wm_check,
                           0, max_len, False, target_type,
                           &actual_type, &actual_format, &actual_size,
                           &bytes_remaining, &tmp_data);

  if (rc != Success || actual_type != XA_WINDOW || x_had_errors_p (dpy))
    {
      if (tmp_data) XFree (tmp_data);
      x_uncatch_errors ();
      unblock_input ();
      return false;
    }

  wmcheck_window = *(Window *) tmp_data;
  XFree (tmp_data);

  /* Check if window exists. */
  XSelectInput (dpy, wmcheck_window, StructureNotifyMask);
  if (x_had_errors_p (dpy))
    {
      x_uncatch_errors_after_check ();
      unblock_input ();
      return false;
    }

  if (dpyinfo->net_supported_window != wmcheck_window)
    {
      /* Window changed, reload atoms */
      if (dpyinfo->net_supported_atoms != NULL)
        XFree (dpyinfo->net_supported_atoms);
      dpyinfo->net_supported_atoms = NULL;
      dpyinfo->nr_net_supported_atoms = 0;
      dpyinfo->net_supported_window = 0;

      target_type = XA_ATOM;
      tmp_data = NULL;
      rc = XGetWindowProperty (dpy, target_window,
                               dpyinfo->Xatom_net_supported,
                               0, max_len, False, target_type,
                               &actual_type, &actual_format, &actual_size,
                               &bytes_remaining, &tmp_data);

      if (rc != Success || actual_type != XA_ATOM || x_had_errors_p (dpy))
        {
          if (tmp_data) XFree (tmp_data);
          x_uncatch_errors ();
          unblock_input ();
          return false;
        }

      dpyinfo->net_supported_atoms = (Atom *)tmp_data;
      dpyinfo->nr_net_supported_atoms = actual_size;
      dpyinfo->net_supported_window = wmcheck_window;
    }

  ret = false;

  for (i = 0; !ret && i < dpyinfo->nr_net_supported_atoms; ++i)
    ret = dpyinfo->net_supported_atoms[i] == want_atom;

  x_uncatch_errors ();
  unblock_input ();

  return ret;
}

static void
set_wm_state (Lisp_Object frame, bool add, Atom atom, Atom value)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (XFRAME (frame));

  x_send_client_event (frame, make_number (0), frame,
                       dpyinfo->Xatom_net_wm_state,
                       make_number (32),
                       /* 1 = add, 0 = remove */
                       Fcons
                       (make_number (add),
                        Fcons
                        (make_fixnum_or_float (atom),
                         (value != 0
                          ? list1 (make_fixnum_or_float (value))
                          : Qnil))));
}

void
x_set_sticky (struct frame *f, Lisp_Object new_value, Lisp_Object old_value)
{
  Lisp_Object frame;
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

  XSETFRAME (frame, f);

  set_wm_state (frame, !NILP (new_value),
                dpyinfo->Xatom_net_wm_state_sticky, None);
}

/**
 * x_set_skip_taskbar:
 *
 * Set frame F's `skip-taskbar' parameter.  If non-nil, this should
 * remove F's icon from the taskbar associated with the display of F's
 * window-system window and inhibit switching to F's window via
 * <Alt>-<TAB>.  If nil, lift these restrictions.
 *
 * Some window managers may not honor this parameter.
 */
void
x_set_skip_taskbar (struct frame *f, Lisp_Object new_value, Lisp_Object old_value)
{
  if (!EQ (new_value, old_value))
    {
#ifdef USE_GTK
      xg_set_skip_taskbar (f, new_value);
#else
      Lisp_Object frame;
      struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

      XSETFRAME (frame, f);
      set_wm_state (frame, !NILP (new_value),
                    dpyinfo->Xatom_net_wm_state_skip_taskbar, None);
#endif /* USE_GTK */
      FRAME_SKIP_TASKBAR (f) = !NILP (new_value);
    }
}

/**
 * x_set_z_group:
 *
 * Set frame F's `z-group' parameter.  If `above', F's window-system
 * window is displayed above all windows that do not have the `above'
 * property set.  If nil, F's window is shown below all windows that
 * have the `above' property set and above all windows that have the
 * `below' property set.  If `below', F's window is displayed below all
 * windows that do not have the `below' property set.
 *
 * Some window managers may not honor this parameter.
 */
void
x_set_z_group (struct frame *f, Lisp_Object new_value, Lisp_Object old_value)
{
  /* We don't care about old_value.  The window manager might have
     reset the value without telling us.  */
  Lisp_Object frame;
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

  XSETFRAME (frame, f);

  if (NILP (new_value))
    {
      set_wm_state (frame, false,
                    dpyinfo->Xatom_net_wm_state_above, None);
      set_wm_state (frame, false,
                    dpyinfo->Xatom_net_wm_state_below, None);
      FRAME_Z_GROUP (f) = z_group_none;
    }
  else if (EQ (new_value, Qabove))
    {
      set_wm_state (frame, true,
                    dpyinfo->Xatom_net_wm_state_above, None);
      set_wm_state (frame, false,
                    dpyinfo->Xatom_net_wm_state_below, None);
      FRAME_Z_GROUP (f) = z_group_above;
    }
  else if (EQ (new_value, Qbelow))
    {
      set_wm_state (frame, false,
                    dpyinfo->Xatom_net_wm_state_above, None);
      set_wm_state (frame, true,
                    dpyinfo->Xatom_net_wm_state_below, None);
      FRAME_Z_GROUP (f) = z_group_below;
    }
  else if (EQ (new_value, Qabove_suspended))
    {
      set_wm_state (frame, false,
                    dpyinfo->Xatom_net_wm_state_above, None);
      FRAME_Z_GROUP (f) = z_group_above_suspended;
    }
  else
    error ("Invalid z-group specification");
}


/* Return the current _NET_WM_STATE.
   SIZE_STATE is set to one of the FULLSCREEN_* values.
   Set *STICKY to the sticky state.

   Return true iff we are not hidden.  */

static bool
get_current_wm_state (struct frame *f,
                      Window window,
                      int *size_state,
                      bool *sticky)
{
  unsigned long actual_size;
  int i;
  bool is_hidden = false;
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
  long max_len = 65536;
  Atom target_type = XA_ATOM;
  /* If XCB is available, we can avoid three XSync calls.  */
#ifdef USE_XCB
  xcb_get_property_cookie_t prop_cookie;
  xcb_get_property_reply_t *prop;
  xcb_atom_t *reply_data;
#else
  Display *dpy = FRAME_X_DISPLAY (f);
  unsigned long bytes_remaining;
  int rc, actual_format;
  Atom actual_type;
  unsigned char *tmp_data = NULL;
  Atom *reply_data;
#endif

  *sticky = false;
  *size_state = FULLSCREEN_NONE;

  block_input ();

#ifdef USE_XCB
  prop_cookie = xcb_get_property (dpyinfo->xcb_connection, 0, window,
                                  dpyinfo->Xatom_net_wm_state,
                                  target_type, 0, max_len);
  prop = xcb_get_property_reply (dpyinfo->xcb_connection, prop_cookie, NULL);
  if (prop && prop->type == target_type)
    {
      int actual_bytes = xcb_get_property_value_length (prop);
      eassume (0 <= actual_bytes);
      actual_size = actual_bytes / sizeof *reply_data;
      reply_data = xcb_get_property_value (prop);
    }
  else
    {
      actual_size = 0;
      is_hidden = FRAME_ICONIFIED_P (f);
    }
#else
  x_catch_errors (dpy);
  rc = XGetWindowProperty (dpy, window, dpyinfo->Xatom_net_wm_state,
                           0, max_len, False, target_type,
                           &actual_type, &actual_format, &actual_size,
                           &bytes_remaining, &tmp_data);

  if (rc == Success && actual_type == target_type && ! x_had_errors_p (dpy))
    reply_data = (Atom *) tmp_data;
  else
    {
      actual_size = 0;
      is_hidden = FRAME_ICONIFIED_P (f);
    }

  x_uncatch_errors ();
#endif

  for (i = 0; i < actual_size; ++i)
    {
      Atom a = reply_data[i];
      if (a == dpyinfo->Xatom_net_wm_state_hidden)
        is_hidden = true;
      else if (a == dpyinfo->Xatom_net_wm_state_maximized_horz)
        {
          if (*size_state == FULLSCREEN_HEIGHT)
            *size_state = FULLSCREEN_MAXIMIZED;
          else
            *size_state = FULLSCREEN_WIDTH;
        }
      else if (a == dpyinfo->Xatom_net_wm_state_maximized_vert)
        {
          if (*size_state == FULLSCREEN_WIDTH)
            *size_state = FULLSCREEN_MAXIMIZED;
          else
            *size_state = FULLSCREEN_HEIGHT;
        }
      else if (a == dpyinfo->Xatom_net_wm_state_fullscreen)
        *size_state = FULLSCREEN_BOTH;
      else if (a == dpyinfo->Xatom_net_wm_state_sticky)
        *sticky = true;
    }

#ifdef USE_XCB
  free (prop);
#else
  if (tmp_data) XFree (tmp_data);
#endif

  unblock_input ();
  return ! is_hidden;
}

/* Do fullscreen as specified in extended window manager hints */

static bool
do_ewmh_fullscreen (struct frame *f)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
  bool have_net_atom = x_wm_supports (f, dpyinfo->Xatom_net_wm_state);
  int cur;
  bool dummy;

  get_current_wm_state (f, FRAME_OUTER_WINDOW (f), &cur, &dummy);

  /* Some window managers don't say they support _NET_WM_STATE, but they do say
     they support _NET_WM_STATE_FULLSCREEN.  Try that also.  */
  if (!have_net_atom)
    have_net_atom = x_wm_supports (f, dpyinfo->Xatom_net_wm_state_fullscreen);

  if (have_net_atom && cur != f->want_fullscreen)
    {
      Lisp_Object frame;

      XSETFRAME (frame, f);

      /* Keep number of calls to set_wm_state as low as possible.
         Some window managers, or possible Gtk+, hangs when too many
         are sent at once.  */
      switch (f->want_fullscreen)
        {
        case FULLSCREEN_BOTH:
          if (cur != FULLSCREEN_BOTH)
            set_wm_state (frame, true, dpyinfo->Xatom_net_wm_state_fullscreen,
                          None);
          break;
        case FULLSCREEN_WIDTH:
          if (x_frame_normalize_before_maximize && cur == FULLSCREEN_MAXIMIZED)
            {
              set_wm_state (frame, false,
                            dpyinfo->Xatom_net_wm_state_maximized_horz,
                            dpyinfo->Xatom_net_wm_state_maximized_vert);
              set_wm_state (frame, true,
                            dpyinfo->Xatom_net_wm_state_maximized_horz, None);
            }
          else
            {
              if (cur == FULLSCREEN_BOTH || cur == FULLSCREEN_HEIGHT
                  || cur == FULLSCREEN_MAXIMIZED)
                set_wm_state (frame, false, dpyinfo->Xatom_net_wm_state_fullscreen,
                              dpyinfo->Xatom_net_wm_state_maximized_vert);
              if (cur != FULLSCREEN_MAXIMIZED || x_frame_normalize_before_maximize)
                set_wm_state (frame, true,
                              dpyinfo->Xatom_net_wm_state_maximized_horz, None);
            }
          break;
        case FULLSCREEN_HEIGHT:
          if (x_frame_normalize_before_maximize && cur == FULLSCREEN_MAXIMIZED)
            {
              set_wm_state (frame, false,
                            dpyinfo->Xatom_net_wm_state_maximized_horz,
                            dpyinfo->Xatom_net_wm_state_maximized_vert);
              set_wm_state (frame, true,
                            dpyinfo->Xatom_net_wm_state_maximized_vert, None);
            }
          else
            {
              if (cur == FULLSCREEN_BOTH || cur == FULLSCREEN_WIDTH
                  || cur == FULLSCREEN_MAXIMIZED)
                set_wm_state (frame, false, dpyinfo->Xatom_net_wm_state_fullscreen,
                              dpyinfo->Xatom_net_wm_state_maximized_horz);
              if (cur != FULLSCREEN_MAXIMIZED || x_frame_normalize_before_maximize)
                set_wm_state (frame, true,
                              dpyinfo->Xatom_net_wm_state_maximized_vert, None);
            }
          break;
        case FULLSCREEN_MAXIMIZED:
          if (x_frame_normalize_before_maximize && cur == FULLSCREEN_BOTH)
            {
              set_wm_state (frame, false,
                            dpyinfo->Xatom_net_wm_state_fullscreen, None);
              set_wm_state (frame, true,
                            dpyinfo->Xatom_net_wm_state_maximized_horz,
                            dpyinfo->Xatom_net_wm_state_maximized_vert);
            }
          else if (x_frame_normalize_before_maximize && cur == FULLSCREEN_WIDTH)
            {
              set_wm_state (frame, false,
                            dpyinfo->Xatom_net_wm_state_maximized_horz, None);
              set_wm_state (frame, true,
                            dpyinfo->Xatom_net_wm_state_maximized_horz,
                            dpyinfo->Xatom_net_wm_state_maximized_vert);
            }
          else if (x_frame_normalize_before_maximize && cur == FULLSCREEN_HEIGHT)
            {
              set_wm_state (frame, false,
                            dpyinfo->Xatom_net_wm_state_maximized_vert, None);
              set_wm_state (frame, true,
                            dpyinfo->Xatom_net_wm_state_maximized_horz,
                            dpyinfo->Xatom_net_wm_state_maximized_vert);
            }
          else
            {
              if (cur == FULLSCREEN_BOTH)
                set_wm_state (frame, false, dpyinfo->Xatom_net_wm_state_fullscreen,
                              None);
              else if (cur == FULLSCREEN_HEIGHT)
                set_wm_state (frame, true,
                              dpyinfo->Xatom_net_wm_state_maximized_horz, None);
              else if (cur == FULLSCREEN_WIDTH)
                set_wm_state (frame, true, None,
                              dpyinfo->Xatom_net_wm_state_maximized_vert);
              else
                set_wm_state (frame, true,
                              dpyinfo->Xatom_net_wm_state_maximized_horz,
                              dpyinfo->Xatom_net_wm_state_maximized_vert);
            }
          break;
        case FULLSCREEN_NONE:
          if (cur == FULLSCREEN_BOTH)
            set_wm_state (frame, false, dpyinfo->Xatom_net_wm_state_fullscreen,
                          None);
          else
            set_wm_state (frame, false,
                          dpyinfo->Xatom_net_wm_state_maximized_horz,
                          dpyinfo->Xatom_net_wm_state_maximized_vert);
        }

      f->want_fullscreen = FULLSCREEN_NONE;

    }

  return have_net_atom;
}

static void
XTfullscreen_hook (struct frame *f)
{
  if (FRAME_VISIBLE_P (f))
    {
      block_input ();
      x_check_fullscreen (f);
      x_sync (f);
      unblock_input ();
    }
}


static bool
x_handle_net_wm_state (struct frame *f, const XPropertyEvent *event)
{
  int value = FULLSCREEN_NONE;
  Lisp_Object lval;
  bool sticky = false;
  bool not_hidden = get_current_wm_state (f, event->window, &value, &sticky);

  lval = Qnil;
  switch (value)
    {
    case FULLSCREEN_WIDTH:
      lval = Qfullwidth;
      break;
    case FULLSCREEN_HEIGHT:
      lval = Qfullheight;
      break;
    case FULLSCREEN_BOTH:
      lval = Qfullboth;
      break;
    case FULLSCREEN_MAXIMIZED:
      lval = Qmaximized;
      break;
    }

  frame_size_history_add
    (f, Qx_handle_net_wm_state, 0, 0,
     list2 (get_frame_param (f, Qfullscreen), lval));

  store_frame_param (f, Qfullscreen, lval);
  store_frame_param (f, Qsticky, sticky ? Qt : Qnil);

  return not_hidden;
}

/* Check if we need to resize the frame due to a fullscreen request.
   If so needed, resize the frame. */
static void
x_check_fullscreen (struct frame *f)
{
  Lisp_Object lval = Qnil;

  if (do_ewmh_fullscreen (f))
    return;

  if (f->output_data.x->parent_desc != FRAME_DISPLAY_INFO (f)->root_window)
    return; /* Only fullscreen without WM or with EWM hints (above). */

  /* Setting fullscreen to nil doesn't do anything.  We could save the
     last non-fullscreen size and restore it, but it seems like a
     lot of work for this unusual case (no window manager running).  */

  if (f->want_fullscreen != FULLSCREEN_NONE)
    {
      int width = FRAME_PIXEL_WIDTH (f), height = FRAME_PIXEL_HEIGHT (f);
      struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

      switch (f->want_fullscreen)
        {
          /* No difference between these two when there is no WM */
        case FULLSCREEN_MAXIMIZED:
          lval = Qmaximized;
          width = x_display_pixel_width (dpyinfo);
          height = x_display_pixel_height (dpyinfo);
          break;
        case FULLSCREEN_BOTH:
          lval = Qfullboth;
          width = x_display_pixel_width (dpyinfo);
          height = x_display_pixel_height (dpyinfo);
          break;
        case FULLSCREEN_WIDTH:
          lval = Qfullwidth;
          width = x_display_pixel_width (dpyinfo);
          height = height + FRAME_MENUBAR_HEIGHT (f);
          break;
        case FULLSCREEN_HEIGHT:
          lval = Qfullheight;
          height = x_display_pixel_height (dpyinfo);
          break;
        default:
          emacs_abort ();
        }

      frame_size_history_add
        (f, Qx_check_fullscreen, width, height, Qnil);

      x_wm_set_size_hint (f, 0, false);

      XResizeWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                     width, height);

      if (FRAME_VISIBLE_P (f))
        x_wait_for_event (f, ConfigureNotify);
      else
        {
          change_frame_size (f, width, height - FRAME_MENUBAR_HEIGHT (f),
                             false, true, false, true);
          x_sync (f);
        }
    }

  /* `x_net_wm_state' might have reset the fullscreen frame parameter,
     restore it. */
  store_frame_param (f, Qfullscreen, lval);
}

/* This function is called by x_set_offset to determine whether the window
   manager interfered with the positioning of the frame.  Type A window
   managers position the surrounding window manager decorations a small
   amount above and left of the user-supplied position.  Type B window
   managers position the surrounding window manager decorations at the
   user-specified position.  If we detect a Type A window manager, we
   compensate by moving the window right and down by the proper amount.  */

static void
x_check_expected_move (struct frame *f, int expected_left, int expected_top)
{
  int current_left = 0, current_top = 0;

  /* x_real_positions returns the left and top offsets of the outermost
     window manager window around the frame.  */

  x_real_positions (f, &current_left, &current_top);

  if (current_left != expected_left || current_top != expected_top)
    {
      /* It's a "Type A" window manager. */

      int adjusted_left;
      int adjusted_top;

        FRAME_DISPLAY_INFO (f)->wm_type = X_WMTYPE_A;
      FRAME_X_OUTPUT (f)->move_offset_left = expected_left - current_left;
      FRAME_X_OUTPUT (f)->move_offset_top = expected_top - current_top;

      /* Now fix the mispositioned frame's location. */

      adjusted_left = expected_left + FRAME_X_OUTPUT (f)->move_offset_left;
      adjusted_top = expected_top + FRAME_X_OUTPUT (f)->move_offset_top;

      XMoveWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                   adjusted_left, adjusted_top);

      x_sync_with_move (f, expected_left, expected_top, false);
    }
  else
    /* It's a "Type B" window manager.  We don't have to adjust the
       frame's position. */

      FRAME_DISPLAY_INFO (f)->wm_type = X_WMTYPE_B;
}


/* Wait for XGetGeometry to return up-to-date position information for a
   recently-moved frame.  Call this immediately after calling XMoveWindow.
   If FUZZY is non-zero, then LEFT and TOP are just estimates of where the
   frame has been moved to, so we use a fuzzy position comparison instead
   of an exact comparison.  */

static void
x_sync_with_move (struct frame *f, int left, int top, bool fuzzy)
{
  int count = 0;

  while (count++ < 50)
    {
      int current_left = 0, current_top = 0;

      /* In theory, this call to XSync only needs to happen once, but in
         practice, it doesn't seem to work, hence the need for the surrounding
         loop.  */

      XSync (FRAME_X_DISPLAY (f), False);
      x_real_positions (f, &current_left, &current_top);

      if (fuzzy)
        {
          /* The left fuzz-factor is 10 pixels.  The top fuzz-factor is 40
             pixels.  */

          if (eabs (current_left - left) <= 10
              && eabs (current_top - top) <= 40)
            return;
        }
      else if (current_left == left && current_top == top)
        return;
    }

  /* As a last resort, just wait 0.5 seconds and hope that XGetGeometry
     will then return up-to-date position info. */

  wait_reading_process_output (0, 500000000, 0, false, Qnil, NULL, 0);
}


/* Wait for an event on frame F matching EVENTTYPE.  */
void
x_wait_for_event (struct frame *f, int eventtype)
{
  int level = interrupt_input_blocked;

  fd_set fds;
  struct timespec tmo, tmo_at, time_now;
  int fd = ConnectionNumber (FRAME_X_DISPLAY (f));

  f->wait_event_type = eventtype;

  /* Set timeout to 0.1 second.  Hopefully not noticeable.
     Maybe it should be configurable.  */
  tmo = make_timespec (0, 100 * 1000 * 1000);
  tmo_at = timespec_add (current_timespec (), tmo);

  while (f->wait_event_type)
    {
      pending_signals = true;
      totally_unblock_input ();
      /* XTread_socket is called after unblock.  */
      block_input ();
      interrupt_input_blocked = level;

      FD_ZERO (&fds);
      FD_SET (fd, &fds);

      time_now = current_timespec ();
      if (timespec_cmp (tmo_at, time_now) < 0)
        break;

      tmo = timespec_sub (tmo_at, time_now);
      if (pselect (fd + 1, &fds, NULL, NULL, &tmo, NULL) == 0)
        break; /* Timeout */
    }

  f->wait_event_type = 0;
}


/* Change the size of frame F's X window to WIDTH/HEIGHT in the case F
   doesn't have a widget.  If CHANGE_GRAVITY, change to
   top-left-corner window gravity for this size change and subsequent
   size changes.  Otherwise leave the window gravity unchanged.  */

static void
x_set_window_size_1 (struct frame *f, bool change_gravity,
                     int width, int height)
{
  int pixelwidth = FRAME_TEXT_TO_PIXEL_WIDTH (f, width);
  int pixelheight = FRAME_TEXT_TO_PIXEL_HEIGHT (f, height);
  int old_width = FRAME_PIXEL_WIDTH (f);
  int old_height = FRAME_PIXEL_HEIGHT (f);
  Lisp_Object fullscreen = get_frame_param (f, Qfullscreen);

  if (change_gravity)
    f->win_gravity = NorthWestGravity;
  x_wm_set_size_hint (f, 0, false);

  /* When the frame is fullheight and we only want to change the width
     or it is fullwidth and we only want to change the height we should
     be able to preserve the fullscreen property.  However, due to the
     fact that we have to send a resize request anyway, the window
     manager will abolish it.  At least the respective size should
     remain unchanged but giving the frame back its normal size will
     be broken ... */
  if (EQ (fullscreen, Qfullwidth) && width == FRAME_TEXT_WIDTH (f))
    {
      frame_size_history_add
        (f, Qx_set_window_size_1, width, height,
         list2 (make_number (old_height),
                make_number (pixelheight + FRAME_MENUBAR_HEIGHT (f))));

      XResizeWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                     old_width, pixelheight + FRAME_MENUBAR_HEIGHT (f));
    }
  else if (EQ (fullscreen, Qfullheight) && height == FRAME_TEXT_HEIGHT (f))
    {
      frame_size_history_add
        (f, Qx_set_window_size_2, width, height,
         list2 (make_number (old_width), make_number (pixelwidth)));

      XResizeWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                     pixelwidth, old_height);
    }

  else
    {
      frame_size_history_add
        (f, Qx_set_window_size_3, width, height,
         list3 (make_number (pixelwidth + FRAME_TOOLBAR_WIDTH (f)),
                make_number (pixelheight + FRAME_TOOLBAR_HEIGHT (f)
                             + FRAME_MENUBAR_HEIGHT (f)),
                make_number (FRAME_MENUBAR_HEIGHT (f))));

      XResizeWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                     pixelwidth, pixelheight + FRAME_MENUBAR_HEIGHT (f));
      fullscreen = Qnil;
    }



  /* We've set {FRAME,PIXEL}_{WIDTH,HEIGHT} to the values we hope to
     receive in the ConfigureNotify event; if we get what we asked
     for, then the event won't cause the screen to become garbaged, so
     we have to make sure to do it here.  */
  SET_FRAME_GARBAGED (f);

  /* Now, strictly speaking, we can't be sure that this is accurate,
     but the window manager will get around to dealing with the size
     change request eventually, and we'll hear how it went when the
     ConfigureNotify event gets here.

     We could just not bother storing any of this information here,
     and let the ConfigureNotify event set everything up, but that
     might be kind of confusing to the Lisp code, since size changes
     wouldn't be reported in the frame parameters until some random
     point in the future when the ConfigureNotify event arrives.

     Pass true for DELAY since we can't run Lisp code inside of
     a BLOCK_INPUT.  */

  /* But the ConfigureNotify may in fact never arrive, and then this is
     not right if the frame is visible.  Instead wait (with timeout)
     for the ConfigureNotify.  */
  if (FRAME_VISIBLE_P (f))
    {
      x_wait_for_event (f, ConfigureNotify);

      if (!NILP (fullscreen))
        /* Try to restore fullscreen state.  */
        {
          store_frame_param (f, Qfullscreen, fullscreen);
          x_set_fullscreen (f, fullscreen, fullscreen);
        }
    }
  else
    {
      change_frame_size (f, width, height, false, true, false, true);
      x_sync (f);
    }
}


/* Call this to change the size of frame F's x-window.
   If CHANGE_GRAVITY, change to top-left-corner window gravity
   for this size change and subsequent size changes.
   Otherwise we leave the window gravity unchanged.  */

void
x_set_window_size (struct frame *f, bool change_gravity,
                   int width, int height, bool pixelwise)
{
  block_input ();

  /* The following breaks our calculations.  If it's really needed,
     think of something else.  */
#if false
  if (NILP (tip_frame) || XFRAME (tip_frame) != f)
    {
      int text_width, text_height;

      /* When the frame is maximized/fullscreen or running under for
         example Xmonad, x_set_window_size_1 will be a no-op.
         In that case, the right thing to do is extend rows/width to
         the current frame size.  We do that first if x_set_window_size_1
         turns out to not be a no-op (there is no way to know).
         The size will be adjusted again if the frame gets a
         ConfigureNotify event as a result of x_set_window_size.  */
      int pixelh = FRAME_PIXEL_HEIGHT (f);
#ifdef USE_X_TOOLKIT
      /* The menu bar is not part of text lines.  The tool bar
         is however.  */
      pixelh -= FRAME_MENUBAR_HEIGHT (f);
#endif
      text_width = FRAME_PIXEL_TO_TEXT_WIDTH (f, FRAME_PIXEL_WIDTH (f));
      text_height = FRAME_PIXEL_TO_TEXT_HEIGHT (f, pixelh);

      change_frame_size (f, text_width, text_height, false, true, false, true);
    }
#endif

  /* Pixelize width and height, if necessary.  */
  if (! pixelwise)
    {
      width = width * FRAME_COLUMN_WIDTH (f);
      height = height * FRAME_LINE_HEIGHT (f);
    }

#ifdef USE_GTK
  if (FRAME_GTK_WIDGET (f))
    xg_frame_set_char_size (f, width, height);
  else
    x_set_window_size_1 (f, change_gravity, width, height);
#else /* not USE_GTK */
  x_set_window_size_1 (f, change_gravity, width, height);
  x_clear_under_internal_border (f);
#endif /* not USE_GTK */

  /* If cursor was outside the new size, mark it as off.  */
  mark_window_cursors_off (XWINDOW (f->root_window));

  /* Clear out any recollection of where the mouse highlighting was,
     since it might be in a place that's outside the new frame size.
     Actually checking whether it is outside is a pain in the neck,
     so don't try--just let the highlighting be done afresh with new size.  */
  cancel_mouse_face (f);

  unblock_input ();

  do_pending_window_change (false);
}

/* Move the mouse to position pixel PIX_X, PIX_Y relative to frame F.  */

void
frame_set_mouse_pixel_position (struct frame *f, int pix_x, int pix_y)
{
  block_input ();

  XWarpPointer (FRAME_X_DISPLAY (f), None, FRAME_X_WINDOW (f),
                0, 0, 0, 0, pix_x, pix_y);
  unblock_input ();
}
\f
/* Raise frame F.  */

void
x_raise_frame (struct frame *f)
{
  block_input ();
  if (FRAME_VISIBLE_P (f))
    XRaiseWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f));
  XFlush (FRAME_X_DISPLAY (f));
  unblock_input ();
}

/* Lower frame F.  */

static void
x_lower_frame (struct frame *f)
{
  if (FRAME_VISIBLE_P (f))
    {
      block_input ();
      XLowerWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f));
      XFlush (FRAME_X_DISPLAY (f));
      unblock_input ();
    }
}

/* Request focus with XEmbed */

void
xembed_request_focus (struct frame *f)
{
  /* See XEmbed Protocol Specification at
     http://freedesktop.org/wiki/Specifications/xembed-spec  */
  if (FRAME_VISIBLE_P (f))
    xembed_send_message (f, CurrentTime,
                         XEMBED_REQUEST_FOCUS, 0, 0, 0);
}

/* Activate frame with Extended Window Manager Hints */

void
x_ewmh_activate_frame (struct frame *f)
{
  /* See Window Manager Specification/Extended Window Manager Hints at
     http://freedesktop.org/wiki/Specifications/wm-spec  */

  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

  if (FRAME_VISIBLE_P (f) && x_wm_supports (f, dpyinfo->Xatom_net_active_window))
    {
      Lisp_Object frame;
      XSETFRAME (frame, f);
      x_send_client_event (frame, make_number (0), frame,
                           dpyinfo->Xatom_net_active_window,
                           make_number (32),
                           list2i (1, dpyinfo->last_user_time));
    }
}

static void
XTframe_raise_lower (struct frame *f, bool raise_flag)
{
  if (raise_flag)
    x_raise_frame (f);
  else
    x_lower_frame (f);
}
\f
/* XEmbed implementation.  */

#if defined USE_X_TOOLKIT || ! defined USE_GTK

/* XEmbed implementation.  */

#define XEMBED_VERSION 0

static void
xembed_set_info (struct frame *f, enum xembed_info flags)
{
  unsigned long data[2];
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

  data[0] = XEMBED_VERSION;
  data[1] = flags;

  XChangeProperty (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                   dpyinfo->Xatom_XEMBED_INFO, dpyinfo->Xatom_XEMBED_INFO,
                   32, PropModeReplace, (unsigned char *) data, 2);
}
#endif /* defined USE_X_TOOLKIT || ! defined USE_GTK */

static void
xembed_send_message (struct frame *f, Time t, enum xembed_message msg,
                     long int detail, long int data1, long int data2)
{
  XEvent event;

  event.xclient.type = ClientMessage;
  event.xclient.window = FRAME_X_OUTPUT (f)->parent_desc;
  event.xclient.message_type = FRAME_DISPLAY_INFO (f)->Xatom_XEMBED;
  event.xclient.format = 32;
  event.xclient.data.l[0] = t;
  event.xclient.data.l[1] = msg;
  event.xclient.data.l[2] = detail;
  event.xclient.data.l[3] = data1;
  event.xclient.data.l[4] = data2;

  XSendEvent (FRAME_X_DISPLAY (f), FRAME_X_OUTPUT (f)->parent_desc,
              False, NoEventMask, &event);
  XSync (FRAME_X_DISPLAY (f), False);
}
\f
/* Change of visibility.  */

/* This function sends the request to make the frame visible, but may
   return before it the frame's visibility is changed.  */

void
x_make_frame_visible (struct frame *f)
{
  if (FRAME_PARENT_FRAME (f))
    {
      if (!FRAME_VISIBLE_P (f))
        {
          block_input ();
#ifdef USE_GTK
          gtk_widget_show_all (FRAME_GTK_OUTER_WIDGET (f));
          XMoveWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                       f->left_pos, f->top_pos);
#else
          XMapRaised (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f));
#endif
          unblock_input ();

          SET_FRAME_VISIBLE (f, true);
          SET_FRAME_ICONIFIED (f, false);
        }
      return;
    }

  block_input ();

  x_set_bitmap_icon (f);

  if (! FRAME_VISIBLE_P (f))
    {
      /* We test asked_for_visible here to make sure we don't
         call x_set_offset a second time
         if we get to x_make_frame_visible a second time
         before the window gets really visible.  */
      if (! FRAME_ICONIFIED_P (f)
          && ! FRAME_X_EMBEDDED_P (f)
          && ! f->output_data.x->asked_for_visible)
        x_set_offset (f, f->left_pos, f->top_pos, 0);

      f->output_data.x->asked_for_visible = true;

      if (! EQ (Vx_no_window_manager, Qt))
        x_wm_set_window_state (f, NormalState);
#ifdef USE_X_TOOLKIT
      if (FRAME_X_EMBEDDED_P (f))
        xembed_set_info (f, XEMBED_MAPPED);
      else
        {
          /* This was XtPopup, but that did nothing for an iconified frame.  */
          XtMapWidget (f->output_data.x->widget);
        }
#else /* not USE_X_TOOLKIT */
#ifdef USE_GTK
      gtk_widget_show_all (FRAME_GTK_OUTER_WIDGET (f));
      gtk_window_deiconify (GTK_WINDOW (FRAME_GTK_OUTER_WIDGET (f)));
#else
      if (FRAME_X_EMBEDDED_P (f))
        xembed_set_info (f, XEMBED_MAPPED);
      else
        XMapRaised (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f));
#endif /* not USE_GTK */
#endif /* not USE_X_TOOLKIT */
    }

  XFlush (FRAME_X_DISPLAY (f));

  /* Synchronize to ensure Emacs knows the frame is visible
     before we do anything else.  We do this loop with input not blocked
     so that incoming events are handled.  */
  {
    /* This must be before UNBLOCK_INPUT
       since events that arrive in response to the actions above
       will set it when they are handled.  */
    bool previously_visible = f->output_data.x->has_been_visible;

    int original_left = f->left_pos;
    int original_top = f->top_pos;

    /* This must come after we set COUNT.  */
    unblock_input ();

    /* We unblock here so that arriving X events are processed.  */

    /* Now move the window back to where it was "supposed to be".
       But don't do it if the gravity is negative.
       When the gravity is negative, this uses a position
       that is 3 pixels too low.  Perhaps that's really the border width.

       Don't do this if the window has never been visible before,
       because the window manager may choose the position
       and we don't want to override it.  */

    if (!FRAME_VISIBLE_P (f)
        && !FRAME_ICONIFIED_P (f)
        && !FRAME_X_EMBEDDED_P (f)
        && !FRAME_PARENT_FRAME (f)
        && f->win_gravity == NorthWestGravity
        && previously_visible)
      {
        Drawable rootw;
        int x, y;
        unsigned int width, height, border, depth;

        block_input ();

        /* On some window managers (such as FVWM) moving an existing
           window, even to the same place, causes the window manager
           to introduce an offset.  This can cause the window to move
           to an unexpected location.  Check the geometry (a little
           slow here) and then verify that the window is in the right
           place.  If the window is not in the right place, move it
           there, and take the potential window manager hit.  */
        XGetGeometry (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                      &rootw, &x, &y, &width, &height, &border, &depth);

        if (original_left != x || original_top != y)
          XMoveWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
                       original_left, original_top);

        unblock_input ();
      }
  }
}

/* Change from mapped state to withdrawn state.  */

/* Make the frame visible (mapped and not iconified).  */

void
x_make_frame_invisible (struct frame *f)
{
  Window window;

  /* Use the frame's outermost window, not the one we normally draw on.  */
  window = FRAME_OUTER_WINDOW (f);

  /* Don't keep the highlight on an invisible frame.  */
  if (FRAME_DISPLAY_INFO (f)->x_highlight_frame == f)
    FRAME_DISPLAY_INFO (f)->x_highlight_frame = 0;

  block_input ();

  /* Before unmapping the window, update the WM_SIZE_HINTS property to claim
     that the current position of the window is user-specified, rather than
     program-specified, so that when the window is mapped again, it will be
     placed at the same location, without forcing the user to position it
     by hand again (they have already done that once for this window.)  */
  x_wm_set_size_hint (f, 0, true);

#ifdef USE_GTK
  if (FRAME_GTK_OUTER_WIDGET (f))
    gtk_widget_hide (FRAME_GTK_OUTER_WIDGET (f));
  else
#else
  if (FRAME_X_EMBEDDED_P (f))
    xembed_set_info (f, 0);
  else
#endif

    if (! XWithdrawWindow (FRAME_X_DISPLAY (f), window,
                           DefaultScreen (FRAME_X_DISPLAY (f))))
      {
        unblock_input ();
        error ("Can't notify window manager of window withdrawal");
      }

  x_sync (f);

  /* We can't distinguish this from iconification
     just by the event that we get from the server.
     So we can't win using the usual strategy of letting
     FRAME_SAMPLE_VISIBILITY set this.  So do it by hand,
     and synchronize with the server to make sure we agree.  */
  SET_FRAME_VISIBLE (f, 0);
  SET_FRAME_ICONIFIED (f, false);

  unblock_input ();
}

/* Change window state from mapped to iconified.  */

void
x_iconify_frame (struct frame *f)
{
#ifdef USE_X_TOOLKIT
  int result;
#endif

  /* Don't keep the highlight on an invisible frame.  */
  if (FRAME_DISPLAY_INFO (f)->x_highlight_frame == f)
    FRAME_DISPLAY_INFO (f)->x_highlight_frame = 0;

  if (FRAME_ICONIFIED_P (f))
    return;

  block_input ();

  x_set_bitmap_icon (f);

#if defined (USE_GTK)
  if (FRAME_GTK_OUTER_WIDGET (f))
    {
      if (! FRAME_VISIBLE_P (f))
        gtk_widget_show_all (FRAME_GTK_OUTER_WIDGET (f));

      gtk_window_iconify (GTK_WINDOW (FRAME_GTK_OUTER_WIDGET (f)));
      SET_FRAME_VISIBLE (f, 0);
      SET_FRAME_ICONIFIED (f, true);
      unblock_input ();
      return;
    }
#endif

#ifdef USE_X_TOOLKIT

  if (! FRAME_VISIBLE_P (f))
    {
      if (! EQ (Vx_no_window_manager, Qt))
        x_wm_set_window_state (f, IconicState);
      /* This was XtPopup, but that did nothing for an iconified frame.  */
      XtMapWidget (f->output_data.x->widget);
      /* The server won't give us any event to indicate
         that an invisible frame was changed to an icon,
         so we have to record it here.  */
      SET_FRAME_VISIBLE (f, 0);
      SET_FRAME_ICONIFIED (f, true);
      unblock_input ();
      return;
    }

  result = XIconifyWindow (FRAME_X_DISPLAY (f),
                           XtWindow (f->output_data.x->widget),
                           DefaultScreen (FRAME_X_DISPLAY (f)));
  unblock_input ();

  if (!result)
    error ("Can't notify window manager of iconification");

  SET_FRAME_ICONIFIED (f, true);
  SET_FRAME_VISIBLE (f, 0);

  block_input ();
  XFlush (FRAME_X_DISPLAY (f));
  unblock_input ();
#else /* not USE_X_TOOLKIT */

  /* Make sure the X server knows where the window should be positioned,
     in case the user deiconifies with the window manager.  */
  if (! FRAME_VISIBLE_P (f)
      && ! FRAME_ICONIFIED_P (f)
      && ! FRAME_X_EMBEDDED_P (f))
    x_set_offset (f, f->left_pos, f->top_pos, 0);

  /* Since we don't know which revision of X we're running, we'll use both
     the X11R3 and X11R4 techniques.  I don't know if this is a good idea.  */

  /* X11R4: send a ClientMessage to the window manager using the
     WM_CHANGE_STATE type.  */
  {
    XEvent msg;

    msg.xclient.window = FRAME_X_WINDOW (f);
    msg.xclient.type = ClientMessage;
    msg.xclient.message_type = FRAME_DISPLAY_INFO (f)->Xatom_wm_change_state;
    msg.xclient.format = 32;
    msg.xclient.data.l[0] = IconicState;

    if (! XSendEvent (FRAME_X_DISPLAY (f),
                      DefaultRootWindow (FRAME_X_DISPLAY (f)),
                      False,
                      SubstructureRedirectMask | SubstructureNotifyMask,
                      &msg))
      {
        unblock_input ();
        error ("Can't notify window manager of iconification");
      }
  }

  /* X11R3: set the initial_state field of the window manager hints to
     IconicState.  */
  x_wm_set_window_state (f, IconicState);

  if (!FRAME_VISIBLE_P (f))
    {
      /* If the frame was withdrawn, before, we must map it.  */
      XMapRaised (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f));
    }

  SET_FRAME_ICONIFIED (f, true);
  SET_FRAME_VISIBLE (f, 0);

  XFlush (FRAME_X_DISPLAY (f));
  unblock_input ();
#endif /* not USE_X_TOOLKIT */
}

\f
/* Free X resources of frame F.  */

void
x_free_frame_resources (struct frame *f)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
  Mouse_HLInfo *hlinfo = &dpyinfo->mouse_highlight;
#ifdef USE_X_TOOLKIT
  Lisp_Object bar;
  struct scroll_bar *b;
#endif

  block_input ();

  /* If a display connection is dead, don't try sending more
     commands to the X server.  */
  if (dpyinfo->display)
    {
      /* Always exit with visible pointer to avoid weird issue
         with Xfixes (Bug#17609).  */
      if (f->pointer_invisible)
        FRAME_DISPLAY_INFO (f)->toggle_visible_pointer (f, 0);

      /* We must free faces before destroying windows because some
         font-driver (e.g. xft) access a window while finishing a
         face.  */
      free_frame_faces (f);
      tear_down_x_back_buffer (f);

      if (f->output_data.x->icon_desc)
        XDestroyWindow (FRAME_X_DISPLAY (f), f->output_data.x->icon_desc);

#ifdef USE_X_TOOLKIT
      /* Explicitly destroy the scroll bars of the frame.  Without
         this, we get "BadDrawable" errors from the toolkit later on,
         presumably from expose events generated for the disappearing
         toolkit scroll bars.  */
      for (bar = FRAME_SCROLL_BARS (f); !NILP (bar); bar = b->next)
        {
          b = XSCROLL_BAR (bar);
          x_scroll_bar_remove (b);
        }
#endif

#ifdef HAVE_X_I18N
      if (FRAME_XIC (f))
        free_frame_xic (f);
#endif

      x_free_cr_resources (f);
#ifdef USE_X_TOOLKIT
      if (f->output_data.x->widget)
        {
          XtDestroyWidget (f->output_data.x->widget);
          f->output_data.x->widget = NULL;
        }
      /* Tooltips don't have widgets, only a simple X window, even if
         we are using a toolkit.  */
      else if (FRAME_X_WINDOW (f))
        XDestroyWindow (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f));

      free_frame_menubar (f);

      if (f->shell_position)
        xfree (f->shell_position);
#else  /* !USE_X_TOOLKIT */

#ifdef USE_GTK
      xg_free_frame_widgets (f);
#endif /* USE_GTK */

      tear_down_x_back_buffer (f);
      if (FRAME_X_WINDOW (f))
          XDestroyWindow (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f));
#endif /* !USE_X_TOOLKIT */

      unload_color (f, FRAME_FOREGROUND_PIXEL (f));
      unload_color (f, FRAME_BACKGROUND_PIXEL (f));
      unload_color (f, f->output_data.x->cursor_pixel);
      unload_color (f, f->output_data.x->cursor_foreground_pixel);
      unload_color (f, f->output_data.x->border_pixel);
      unload_color (f, f->output_data.x->mouse_pixel);

      if (f->output_data.x->scroll_bar_background_pixel != -1)
        unload_color (f, f->output_data.x->scroll_bar_background_pixel);
      if (f->output_data.x->scroll_bar_foreground_pixel != -1)
        unload_color (f, f->output_data.x->scroll_bar_foreground_pixel);
#if defined (USE_LUCID) && defined (USE_TOOLKIT_SCROLL_BARS)
      /* Scrollbar shadow colors.  */
      if (f->output_data.x->scroll_bar_top_shadow_pixel != -1)
        unload_color (f, f->output_data.x->scroll_bar_top_shadow_pixel);
      if (f->output_data.x->scroll_bar_bottom_shadow_pixel != -1)
        unload_color (f, f->output_data.x->scroll_bar_bottom_shadow_pixel);
#endif /* USE_LUCID && USE_TOOLKIT_SCROLL_BARS */
      if (f->output_data.x->white_relief.pixel != -1)
        unload_color (f, f->output_data.x->white_relief.pixel);
      if (f->output_data.x->black_relief.pixel != -1)
        unload_color (f, f->output_data.x->black_relief.pixel);

      x_free_gcs (f);

      /* Free extra GCs allocated by x_setup_relief_colors.  */
      if (f->output_data.x->white_relief.gc)
        {
          XFreeGC (dpyinfo->display, f->output_data.x->white_relief.gc);
          f->output_data.x->white_relief.gc = 0;
        }
      if (f->output_data.x->black_relief.gc)
        {
          XFreeGC (dpyinfo->display, f->output_data.x->black_relief.gc);
          f->output_data.x->black_relief.gc = 0;
        }

      /* Free cursors.  */
      if (f->output_data.x->text_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->text_cursor);
      if (f->output_data.x->nontext_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->nontext_cursor);
      if (f->output_data.x->modeline_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->modeline_cursor);
      if (f->output_data.x->hand_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->hand_cursor);
      if (f->output_data.x->hourglass_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->hourglass_cursor);
      if (f->output_data.x->horizontal_drag_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->horizontal_drag_cursor);
      if (f->output_data.x->vertical_drag_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->vertical_drag_cursor);
      if (f->output_data.x->left_edge_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->left_edge_cursor);
      if (f->output_data.x->top_left_corner_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->top_left_corner_cursor);
      if (f->output_data.x->top_edge_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->top_edge_cursor);
      if (f->output_data.x->top_right_corner_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->top_right_corner_cursor);
      if (f->output_data.x->right_edge_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->right_edge_cursor);
      if (f->output_data.x->bottom_right_corner_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->bottom_right_corner_cursor);
      if (f->output_data.x->bottom_edge_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->bottom_edge_cursor);
      if (f->output_data.x->bottom_left_corner_cursor != 0)
        XFreeCursor (FRAME_X_DISPLAY (f), f->output_data.x->bottom_left_corner_cursor);

      XFlush (FRAME_X_DISPLAY (f));
    }

  xfree (f->output_data.x->saved_menu_event);
  xfree (f->output_data.x);
  f->output_data.x = NULL;

  if (f == dpyinfo->x_focus_frame)
    dpyinfo->x_focus_frame = 0;
  if (f == dpyinfo->x_focus_event_frame)
    dpyinfo->x_focus_event_frame = 0;
  if (f == dpyinfo->x_highlight_frame)
    dpyinfo->x_highlight_frame = 0;
  if (f == hlinfo->mouse_face_mouse_frame)
    reset_mouse_highlight (hlinfo);

  unblock_input ();
}


/* Destroy the X window of frame F.  */

static void
x_destroy_window (struct frame *f)
{
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);

  /* If a display connection is dead, don't try sending more
     commands to the X server.  */
  if (dpyinfo->display != 0)
    x_free_frame_resources (f);

  dpyinfo->reference_count--;
}

\f
/* Setting window manager hints.  */

/* Set the normal size hints for the window manager, for frame F.
   FLAGS is the flags word to use--or 0 meaning preserve the flags
   that the window now has.
   If USER_POSITION, set the USPosition
   flag (this is useful when FLAGS is 0).
   The GTK version is in gtkutils.c.  */

#ifndef USE_GTK
void
x_wm_set_size_hint (struct frame *f, long flags, bool user_position)
{
  XSizeHints size_hints;
  Window window = FRAME_OUTER_WINDOW (f);

  if (!window)
    return;

#ifdef USE_X_TOOLKIT
  if (f->output_data.x->widget)
    {
      widget_update_wm_size_hints (f->output_data.x->widget);
      return;
    }
#endif

  /* Setting PMaxSize caused various problems.  */
  size_hints.flags = PResizeInc | PMinSize /* | PMaxSize */;

  size_hints.x = f->left_pos;
  size_hints.y = f->top_pos;

  size_hints.width = FRAME_PIXEL_WIDTH (f);
  size_hints.height = FRAME_PIXEL_HEIGHT (f);

  size_hints.width_inc = frame_resize_pixelwise ? 1 : FRAME_COLUMN_WIDTH (f);
  size_hints.height_inc = frame_resize_pixelwise ? 1 : FRAME_LINE_HEIGHT (f);

  size_hints.max_width = x_display_pixel_width (FRAME_DISPLAY_INFO (f))
    - FRAME_TEXT_COLS_TO_PIXEL_WIDTH (f, 0);
  size_hints.max_height = x_display_pixel_height (FRAME_DISPLAY_INFO (f))
    - FRAME_TEXT_LINES_TO_PIXEL_HEIGHT (f, 0);

  /* Calculate the base and minimum sizes.  */
  {
    int base_width, base_height;

    base_width = FRAME_TEXT_COLS_TO_PIXEL_WIDTH (f, 0);
    base_height = FRAME_TEXT_LINES_TO_PIXEL_HEIGHT (f, 0);

    /* The window manager uses the base width hints to calculate the
       current number of rows and columns in the frame while
       resizing; min_width and min_height aren't useful for this
       purpose, since they might not give the dimensions for a
       zero-row, zero-column frame.  */

    size_hints.flags |= PBaseSize;
    size_hints.base_width = base_width;
    size_hints.base_height = base_height + FRAME_MENUBAR_HEIGHT (f);
    size_hints.min_width  = base_width;
    size_hints.min_height = base_height;
  }

  /* If we don't need the old flags, we don't need the old hint at all.  */
  if (flags)
    {
      size_hints.flags |= flags;
      goto no_read;
    }

  {
    XSizeHints hints;           /* Sometimes I hate X Windows... */
    long supplied_return;
    int value;

    value = XGetWMNormalHints (FRAME_X_DISPLAY (f), window, &hints,
                               &supplied_return);

    if (flags)
      size_hints.flags |= flags;
    else
      {
        if (value == 0)
          hints.flags = 0;
        if (hints.flags & PSize)
          size_hints.flags |= PSize;
        if (hints.flags & PPosition)
          size_hints.flags |= PPosition;
        if (hints.flags & USPosition)
          size_hints.flags |= USPosition;
        if (hints.flags & USSize)
          size_hints.flags |= USSize;
      }
  }

 no_read:

#ifdef PWinGravity
  size_hints.win_gravity = f->win_gravity;
  size_hints.flags |= PWinGravity;

  if (user_position)
    {
      size_hints.flags &= ~ PPosition;
      size_hints.flags |= USPosition;
    }
#endif /* PWinGravity */

  XSetWMNormalHints (FRAME_X_DISPLAY (f), window, &size_hints);
}
#endif /* not USE_GTK */

/* Used for IconicState or NormalState */

static void
x_wm_set_window_state (struct frame *f, int state)
{
#ifdef USE_X_TOOLKIT
  Arg al[1];

  XtSetArg (al[0], XtNinitialState, state);
  XtSetValues (f->output_data.x->widget, al, 1);
#else /* not USE_X_TOOLKIT */
  Window window = FRAME_X_WINDOW (f);

  f->output_data.x->wm_hints.flags |= StateHint;
  f->output_data.x->wm_hints.initial_state = state;

  XSetWMHints (FRAME_X_DISPLAY (f), window, &f->output_data.x->wm_hints);
#endif /* not USE_X_TOOLKIT */
}

static void
x_wm_set_icon_pixmap (struct frame *f, ptrdiff_t pixmap_id)
{
  Pixmap icon_pixmap, icon_mask;

#if !defined USE_X_TOOLKIT && !defined USE_GTK
  Window window = FRAME_OUTER_WINDOW (f);
#endif

  if (pixmap_id > 0)
    {
      icon_pixmap = x_bitmap_pixmap (f, pixmap_id);
      f->output_data.x->wm_hints.icon_pixmap = icon_pixmap;
      icon_mask = x_bitmap_mask (f, pixmap_id);
      f->output_data.x->wm_hints.icon_mask = icon_mask;
    }
  else
    {
      /* It seems there is no way to turn off use of an icon
         pixmap.  */
      return;
    }


#ifdef USE_GTK
  {
    xg_set_frame_icon (f, icon_pixmap, icon_mask);
    return;
  }

#elif defined (USE_X_TOOLKIT) /* same as in x_wm_set_window_state.  */

  {
    Arg al[1];
    XtSetArg (al[0], XtNiconPixmap, icon_pixmap);
    XtSetValues (f->output_data.x->widget, al, 1);
    XtSetArg (al[0], XtNiconMask, icon_mask);
    XtSetValues (f->output_data.x->widget, al, 1);
  }

#else /* not USE_X_TOOLKIT && not USE_GTK */

  f->output_data.x->wm_hints.flags |= (IconPixmapHint | IconMaskHint);
  XSetWMHints (FRAME_X_DISPLAY (f), window, &f->output_data.x->wm_hints);

#endif /* not USE_X_TOOLKIT && not USE_GTK */
}

void
x_wm_set_icon_position (struct frame *f, int icon_x, int icon_y)
{
  Window window = FRAME_OUTER_WINDOW (f);

  f->output_data.x->wm_hints.flags |= IconPositionHint;
  f->output_data.x->wm_hints.icon_x = icon_x;
  f->output_data.x->wm_hints.icon_y = icon_y;

  XSetWMHints (FRAME_X_DISPLAY (f), window, &f->output_data.x->wm_hints);
}

\f
/***********************************************************************
                                Fonts
 ***********************************************************************/

#ifdef GLYPH_DEBUG

/* Check that FONT is valid on frame F.  It is if it can be found in F's
   font table.  */

static void
x_check_font (struct frame *f, struct font *font)
{
  eassert (font != NULL && ! NILP (font->props[FONT_TYPE_INDEX]));
  if (font->driver->check)
    eassert (font->driver->check (f, font) == 0);
}

#endif /* GLYPH_DEBUG */

\f
/***********************************************************************
                            Initialization
 ***********************************************************************/

#ifdef USE_X_TOOLKIT
static XrmOptionDescRec emacs_options[] = {
  {(char *) "-geometry", (char *) ".geometry", XrmoptionSepArg, NULL},
  {(char *) "-iconic", (char *) ".iconic", XrmoptionNoArg, (XtPointer) "yes"},

  {(char *) "-internal-border-width",
   (char *) "*EmacsScreen.internalBorderWidth", XrmoptionSepArg, NULL},
  {(char *) "-ib", (char *) "*EmacsScreen.internalBorderWidth",
   XrmoptionSepArg, NULL},
  {(char *) "-T", (char *) "*EmacsShell.title", XrmoptionSepArg, NULL},
  {(char *) "-wn", (char *) "*EmacsShell.title", XrmoptionSepArg, NULL},
  {(char *) "-title", (char *) "*EmacsShell.title", XrmoptionSepArg, NULL},
  {(char *) "-iconname", (char *) "*EmacsShell.iconName",
   XrmoptionSepArg, NULL},
  {(char *) "-in", (char *) "*EmacsShell.iconName", XrmoptionSepArg, NULL},
  {(char *) "-mc", (char *) "*pointerColor", XrmoptionSepArg, NULL},
  {(char *) "-cr", (char *) "*cursorColor", XrmoptionSepArg, NULL}
};

/* Whether atimer for Xt timeouts is activated or not.  */

static bool x_timeout_atimer_activated_flag;

#endif /* USE_X_TOOLKIT */

static int x_initialized;

/* Test whether two display-name strings agree up to the dot that separates
   the screen number from the server number.  */
static bool
same_x_server (const char *name1, const char *name2)
{
  bool seen_colon = false;
  Lisp_Object sysname = Fsystem_name ();
  const char *system_name = SSDATA (sysname);
  ptrdiff_t system_name_length = SBYTES (sysname);
  ptrdiff_t length_until_period = 0;

  while (system_name[length_until_period] != 0
         && system_name[length_until_period] != '.')
    length_until_period++;

  /* Treat `unix' like an empty host name.  */
  if (! strncmp (name1, "unix:", 5))
    name1 += 4;
  if (! strncmp (name2, "unix:", 5))
    name2 += 4;
  /* Treat this host's name like an empty host name.  */
  if (! strncmp (name1, system_name, system_name_length)
      && name1[system_name_length] == ':')
    name1 += system_name_length;
  if (! strncmp (name2, system_name, system_name_length)
      && name2[system_name_length] == ':')
    name2 += system_name_length;
  /* Treat this host's domainless name like an empty host name.  */
  if (! strncmp (name1, system_name, length_until_period)
      && name1[length_until_period] == ':')
    name1 += length_until_period;
  if (! strncmp (name2, system_name, length_until_period)
      && name2[length_until_period] == ':')
    name2 += length_until_period;

  for (; *name1 != '\0' && *name1 == *name2; name1++, name2++)
    {
      if (*name1 == ':')
        seen_colon = true;
      if (seen_colon && *name1 == '.')
        return true;
    }
  return (seen_colon
          && (*name1 == '.' || *name1 == '\0')
          && (*name2 == '.' || *name2 == '\0'));
}

/* Count number of set bits in mask and number of bits to shift to
   get to the first bit.  With MASK 0x7e0, *BITS is set to 6, and *OFFSET
   to 5.  */
static void
get_bits_and_offset (unsigned long mask, int *bits, int *offset)
{
  int nr = 0;
  int off = 0;

  while (!(mask & 1))
    {
      off++;
      mask >>= 1;
    }

  while (mask & 1)
    {
      nr++;
      mask >>= 1;
    }

  *offset = off;
  *bits = nr;
}

/* Return true iff display DISPLAY is available for use.
   But don't permanently open it, just test its availability.  */

bool
x_display_ok (const char *display)
{
  /* XOpenDisplay fails if it gets a signal.  Block SIGIO which may arrive.  */
  unrequest_sigio ();
  Display *dpy = XOpenDisplay (display);
  request_sigio ();
  if (!dpy)
    return false;
  XCloseDisplay (dpy);
  return true;
}

#ifdef USE_GTK
static void
my_log_handler (const gchar *log_domain, GLogLevelFlags log_level,
                const gchar *msg, gpointer user_data)
{
  if (!strstr (msg, "g_set_prgname"))
      fprintf (stderr, "%s-WARNING **: %s\n", log_domain, msg);
}
#endif

/* Create invisible cursor on X display referred by DPYINFO.  */

static Cursor
make_invisible_cursor (struct x_display_info *dpyinfo)
{
  Display *dpy = dpyinfo->display;
  static char const no_data[] = { 0 };
  Pixmap pix;
  XColor col;
  Cursor c = 0;

  x_catch_errors (dpy);
  pix = XCreateBitmapFromData (dpy, dpyinfo->root_window, no_data, 1, 1);
  if (! x_had_errors_p (dpy) && pix != None)
    {
      Cursor pixc;
      col.pixel = 0;
      col.red = col.green = col.blue = 0;
      col.flags = DoRed | DoGreen | DoBlue;
      pixc = XCreatePixmapCursor (dpy, pix, pix, &col, &col, 0, 0);
      if (! x_had_errors_p (dpy) && pixc != None)
        c = pixc;
      XFreePixmap (dpy, pix);
    }

  x_uncatch_errors ();

  return c;
}

/* True if DPY supports Xfixes extension >= 4.  */

static bool
x_probe_xfixes_extension (Display *dpy)
{
#ifdef HAVE_XFIXES
  int major, minor;
  return XFixesQueryVersion (dpy, &major, &minor) && major >= 4;
#else
  return false;
#endif /* HAVE_XFIXES */
}

/* Toggle mouse pointer visibility on frame F by using Xfixes functions.  */

static void
xfixes_toggle_visible_pointer (struct frame *f, bool invisible)
{
#ifdef HAVE_XFIXES
  if (invisible)
    XFixesHideCursor (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f));
  else
    XFixesShowCursor (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f));
  f->pointer_invisible = invisible;
#else
  emacs_abort ();
#endif /* HAVE_XFIXES */
}

/* Toggle mouse pointer visibility on frame F by using invisible cursor.  */

static void
x_toggle_visible_pointer (struct frame *f, bool invisible)
{
  eassert (FRAME_DISPLAY_INFO (f)->invisible_cursor != 0);
  if (invisible)
    XDefineCursor (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
                   FRAME_DISPLAY_INFO (f)->invisible_cursor);
  else
    XDefineCursor (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
                   f->output_data.x->current_cursor);
  f->pointer_invisible = invisible;
}

/* Setup pointer blanking, prefer Xfixes if available.  */

static void
x_setup_pointer_blanking (struct x_display_info *dpyinfo)
{
  /* FIXME: the brave tester should set EMACS_XFIXES because we're suspecting
     X server bug, see http://debbugs.gnu.org/cgi/bugreport.cgi?bug=17609.  */
  if (egetenv ("EMACS_XFIXES") && x_probe_xfixes_extension (dpyinfo->display))
    dpyinfo->toggle_visible_pointer = xfixes_toggle_visible_pointer;
  else
    {
      dpyinfo->toggle_visible_pointer = x_toggle_visible_pointer;
      dpyinfo->invisible_cursor = make_invisible_cursor (dpyinfo);
    }
}

/* Current X display connection identifier.  Incremented for each next
   connection established.  */
static unsigned x_display_id;

/* Open a connection to X display DISPLAY_NAME, and return
   the structure that describes the open display.
   If we cannot contact the display, return null.  */

struct x_display_info *
x_term_init (Lisp_Object display_name, char *xrm_option, char *resource_name)
{
  Display *dpy;
  struct terminal *terminal;
  struct x_display_info *dpyinfo;
  XrmDatabase xrdb;
#ifdef USE_XCB
  xcb_connection_t *xcb_conn;
#endif

  block_input ();

  if (!x_initialized)
    {
      x_initialize ();
      ++x_initialized;
    }

  if (! x_display_ok (SSDATA (display_name)))
    error ("Display %s can't be opened", SSDATA (display_name));

#ifdef USE_GTK
  {
#define NUM_ARGV 10
    int argc;
    char *argv[NUM_ARGV];
    char **argv2 = argv;
    guint id;

    if (x_initialized++ > 1)
      {
        xg_display_open (SSDATA (display_name), &dpy);
      }
    else
      {
        static char display_opt[] = "--display";
        static char name_opt[] = "--name";

        for (argc = 0; argc < NUM_ARGV; ++argc)
          argv[argc] = 0;

        argc = 0;
        argv[argc++] = initial_argv[0];

        if (! NILP (display_name))
          {
            argv[argc++] = display_opt;
            argv[argc++] = SSDATA (display_name);
          }

        argv[argc++] = name_opt;
        argv[argc++] = resource_name;

        XSetLocaleModifiers ("");

        /* Work around GLib bug that outputs a faulty warning. See
           https://bugzilla.gnome.org/show_bug.cgi?id=563627.  */
        id = g_log_set_handler ("GLib", G_LOG_LEVEL_WARNING | G_LOG_FLAG_FATAL
                                  | G_LOG_FLAG_RECURSION, my_log_handler, NULL);

        /* NULL window -> events for all windows go to our function.
           Call before gtk_init so Gtk+ event filters comes after our.  */
        gdk_window_add_filter (NULL, event_handler_gdk, NULL);

        /* gtk_init does set_locale.  Fix locale before and after.  */
        fixup_locale ();
        unrequest_sigio (); /* See comment in x_display_ok.  */
        gtk_init (&argc, &argv2);
        request_sigio ();
        fixup_locale ();

        g_log_remove_handler ("GLib", id);

        xg_initialize ();

        dpy = DEFAULT_GDK_DISPLAY ();

#if ! GTK_CHECK_VERSION (2, 90, 0)
        /* Load our own gtkrc if it exists.  */
        {
          const char *file = "~/.emacs.d/gtkrc";
          Lisp_Object s, abs_file;

          s = build_string (file);
          abs_file = Fexpand_file_name (s, Qnil);

          if (! NILP (abs_file) && !NILP (Ffile_readable_p (abs_file)))
            gtk_rc_parse (SSDATA (abs_file));
        }
#endif

        XSetErrorHandler (x_error_handler);
        XSetIOErrorHandler (x_io_error_quitter);
      }
  }
#else /* not USE_GTK */
#ifdef USE_X_TOOLKIT
  /* weiner@footloose.sps.mot.com reports that this causes
     errors with X11R5:
           X protocol error: BadAtom (invalid Atom parameter)
           on protocol request 18skiloaf.
     So let's not use it until R6.  */
#ifdef HAVE_X11XTR6
  XtSetLanguageProc (NULL, NULL, NULL);
#endif

  {
    int argc = 0;
    char *argv[3];

    argv[0] = (char *) "";
    argc = 1;
    if (xrm_option)
      {
        argv[argc++] = (char *) "-xrm";
        argv[argc++] = xrm_option;
      }
    turn_on_atimers (false);
    unrequest_sigio ();  /* See comment in x_display_ok.  */
    dpy = XtOpenDisplay (Xt_app_con, SSDATA (display_name),
                         resource_name, EMACS_CLASS,
                         emacs_options, XtNumber (emacs_options),
                         &argc, argv);
    request_sigio ();
    turn_on_atimers (true);

#ifdef HAVE_X11XTR6
    /* I think this is to compensate for XtSetLanguageProc.  */
    fixup_locale ();
#endif
  }

#else /* not USE_X_TOOLKIT */
  XSetLocaleModifiers ("");
  unrequest_sigio ();  /* See comment in x_display_ok.  */
  dpy = XOpenDisplay (SSDATA (display_name));
  request_sigio ();
#endif /* not USE_X_TOOLKIT */
#endif /* not USE_GTK*/

  /* Detect failure.  */
  if (dpy == 0)
    {
      unblock_input ();
      return 0;
    }

#ifdef USE_XCB
  xcb_conn = XGetXCBConnection (dpy);
  if (xcb_conn == 0)
    {
#ifdef USE_GTK
      xg_display_close (dpy);
#else
#ifdef USE_X_TOOLKIT
      XtCloseDisplay (dpy);
#else
      XCloseDisplay (dpy);
#endif
#endif /* ! USE_GTK */

      unblock_input ();
      return 0;
    }
#endif

  /* We have definitely succeeded.  Record the new connection.  */

  dpyinfo = xzalloc (sizeof *dpyinfo);
  terminal = x_create_terminal (dpyinfo);

  {
    struct x_display_info *share;

    for (share = x_display_list; share; share = share->next)
      if (same_x_server (SSDATA (XCAR (share->name_list_element)),
                         SSDATA (display_name)))
        break;
    if (share)
      terminal->kboard = share->terminal->kboard;
    else
      {
        terminal->kboard = allocate_kboard (Qx);

        if (!EQ (XSYMBOL (Qvendor_specific_keysyms)->function, Qunbound))
          {
            char *vendor = ServerVendor (dpy);

            /* Temporarily hide the partially initialized terminal.  */
            terminal_list = terminal->next_terminal;
            unblock_input ();
            kset_system_key_alist
              (terminal->kboard,
               call1 (Qvendor_specific_keysyms,
                      vendor ? build_string (vendor) : empty_unibyte_string));
            block_input ();
            terminal->next_terminal = terminal_list;
            terminal_list = terminal;
          }

        /* Don't let the initial kboard remain current longer than necessary.
           That would cause problems if a file loaded on startup tries to
           prompt in the mini-buffer.  */
        if (current_kboard == initial_kboard)
          current_kboard = terminal->kboard;
      }
    terminal->kboard->reference_count++;
  }

  /* Put this display on the chain.  */
  dpyinfo->next = x_display_list;
  x_display_list = dpyinfo;

  dpyinfo->name_list_element = Fcons (display_name, Qnil);
  dpyinfo->display = dpy;
  dpyinfo->connection = ConnectionNumber (dpyinfo->display);
#ifdef USE_XCB
  dpyinfo->xcb_connection = xcb_conn;
#endif

  /* http://lists.gnu.org/archive/html/emacs-devel/2015-11/msg00194.html  */
  dpyinfo->smallest_font_height = 1;
  dpyinfo->smallest_char_width = 1;

  /* Set the name of the terminal. */
  terminal->name = xlispstrdup (display_name);

#if false
  XSetAfterFunction (x_current_display, x_trace_wire);
#endif

  Lisp_Object system_name = Fsystem_name ();
  ptrdiff_t nbytes;
  if (INT_ADD_WRAPV (SBYTES (Vinvocation_name), SBYTES (system_name) + 2,
                     &nbytes))
    memory_full (SIZE_MAX);
  dpyinfo->x_id = ++x_display_id;
  dpyinfo->x_id_name = xmalloc (nbytes);
  char *nametail = lispstpcpy (dpyinfo->x_id_name, Vinvocation_name);
  *nametail++ = '@';
  lispstpcpy (nametail, system_name);

  /* Figure out which modifier bits mean what.  */
  x_find_modifier_meanings (dpyinfo);

  /* Get the scroll bar cursor.  */
#ifdef USE_GTK
  /* We must create a GTK cursor, it is required for GTK widgets.  */
  dpyinfo->xg_cursor = xg_create_default_cursor (dpyinfo->display);
#endif /* USE_GTK */

  dpyinfo->vertical_scroll_bar_cursor
    = XCreateFontCursor (dpyinfo->display, XC_sb_v_double_arrow);

  dpyinfo->horizontal_scroll_bar_cursor
    = XCreateFontCursor (dpyinfo->display, XC_sb_h_double_arrow);

  xrdb = x_load_resources (dpyinfo->display, xrm_option,
                           resource_name, EMACS_CLASS);
#ifdef HAVE_XRMSETDATABASE
  XrmSetDatabase (dpyinfo->display, xrdb);
#else
  dpyinfo->display->db = xrdb;
#endif
  /* Put the rdb where we can find it in a way that works on
     all versions.  */
  dpyinfo->xrdb = xrdb;

  dpyinfo->screen = ScreenOfDisplay (dpyinfo->display,
                                     DefaultScreen (dpyinfo->display));
  select_visual (dpyinfo);
  dpyinfo->cmap = DefaultColormapOfScreen (dpyinfo->screen);
  dpyinfo->root_window = RootWindowOfScreen (dpyinfo->screen);
  dpyinfo->icon_bitmap_id = -1;
  dpyinfo->wm_type = X_WMTYPE_UNKNOWN;

  reset_mouse_highlight (&dpyinfo->mouse_highlight);

  /* See if we can construct pixel values from RGB values.  */
  if (dpyinfo->visual->class == TrueColor)
    {
      get_bits_and_offset (dpyinfo->visual->red_mask,
                           &dpyinfo->red_bits, &dpyinfo->red_offset);
      get_bits_and_offset (dpyinfo->visual->blue_mask,
                           &dpyinfo->blue_bits, &dpyinfo->blue_offset);
      get_bits_and_offset (dpyinfo->visual->green_mask,
                           &dpyinfo->green_bits, &dpyinfo->green_offset);
    }

  /* See if a private colormap is requested.  */
  if (dpyinfo->visual == DefaultVisualOfScreen (dpyinfo->screen))
    {
      if (dpyinfo->visual->class == PseudoColor)
        {
          AUTO_STRING (privateColormap, "privateColormap");
          AUTO_STRING (PrivateColormap, "PrivateColormap");
          Lisp_Object value
            = display_x_get_resource (dpyinfo, privateColormap,
                                      PrivateColormap, Qnil, Qnil);
          if (STRINGP (value)
              && (!strcmp (SSDATA (value), "true")
                  || !strcmp (SSDATA (value), "on")))
            dpyinfo->cmap = XCopyColormapAndFree (dpyinfo->display, dpyinfo->cmap);
        }
    }
  else
    dpyinfo->cmap = XCreateColormap (dpyinfo->display, dpyinfo->root_window,
                                     dpyinfo->visual, AllocNone);

#ifdef HAVE_XDBE
  dpyinfo->supports_xdbe = false;
  int xdbe_major;
  int xdbe_minor;
  if (XdbeQueryExtension (dpyinfo->display, &xdbe_major, &xdbe_minor))
    dpyinfo->supports_xdbe = true;
#endif

#ifdef HAVE_XFT
  {
    /* If we are using Xft, the following precautions should be made:

       1. Make sure that the Xrender extension is added before the Xft one.
       Otherwise, the close-display hook set by Xft is called after the one
       for Xrender, and the former tries to re-add the latter.  This results
       in inconsistency of internal states and leads to X protocol error when
       one reconnects to the same X server (Bug#1696).

       2. Check dpi value in X resources.  It is better we use it as well,
       since Xft will use it, as will all Gnome applications.  If our real DPI
       is smaller or larger than the one Xft uses, our font will look smaller
       or larger than other for other applications, even if it is the same
       font name (monospace-10 for example).  */

    int event_base, error_base;
    char *v;
    double d;

    XRenderQueryExtension (dpyinfo->display, &event_base, &error_base);

    v = XGetDefault (dpyinfo->display, "Xft", "dpi");
    if (v != NULL && sscanf (v, "%lf", &d) == 1)
      dpyinfo->resy = dpyinfo->resx = d;
  }
#endif

  if (dpyinfo->resy < 1)
    {
      int screen_number = XScreenNumberOfScreen (dpyinfo->screen);
      double pixels = DisplayHeight (dpyinfo->display, screen_number);
      double mm = DisplayHeightMM (dpyinfo->display, screen_number);
      /* Mac OS X 10.3's Xserver sometimes reports 0.0mm.  */
      dpyinfo->resy = (mm < 1) ? 100 : pixels * 25.4 / mm;
      pixels = DisplayWidth (dpyinfo->display, screen_number);
      mm = DisplayWidthMM (dpyinfo->display, screen_number);
      /* Mac OS X 10.3's Xserver sometimes reports 0.0mm.  */
      dpyinfo->resx = (mm < 1) ? 100 : pixels * 25.4 / mm;
    }

  {
    static const struct
    {
      const char *name;
      int offset;
    } atom_refs[] = {
#define ATOM_REFS_INIT(string, member) \
      { string, offsetof (struct x_display_info, member) },
      ATOM_REFS_INIT ("WM_PROTOCOLS", Xatom_wm_protocols)
      ATOM_REFS_INIT ("WM_TAKE_FOCUS", Xatom_wm_take_focus)
      ATOM_REFS_INIT ("WM_SAVE_YOURSELF", Xatom_wm_save_yourself)
      ATOM_REFS_INIT ("WM_DELETE_WINDOW", Xatom_wm_delete_window)
      ATOM_REFS_INIT ("WM_CHANGE_STATE", Xatom_wm_change_state)
      ATOM_REFS_INIT ("WM_CONFIGURE_DENIED", Xatom_wm_configure_denied)
      ATOM_REFS_INIT ("WM_MOVED", Xatom_wm_window_moved)
      ATOM_REFS_INIT ("WM_CLIENT_LEADER", Xatom_wm_client_leader)
      ATOM_REFS_INIT ("Editres", Xatom_editres)
      ATOM_REFS_INIT ("CLIPBOARD", Xatom_CLIPBOARD)
      ATOM_REFS_INIT ("TIMESTAMP", Xatom_TIMESTAMP)
      ATOM_REFS_INIT ("TEXT", Xatom_TEXT)
      ATOM_REFS_INIT ("COMPOUND_TEXT", Xatom_COMPOUND_TEXT)
      ATOM_REFS_INIT ("UTF8_STRING", Xatom_UTF8_STRING)
      ATOM_REFS_INIT ("DELETE", Xatom_DELETE)
      ATOM_REFS_INIT ("MULTIPLE", Xatom_MULTIPLE)
      ATOM_REFS_INIT ("INCR", Xatom_INCR)
      ATOM_REFS_INIT ("_EMACS_TMP_",  Xatom_EMACS_TMP)
      ATOM_REFS_INIT ("TARGETS", Xatom_TARGETS)
      ATOM_REFS_INIT ("NULL", Xatom_NULL)
      ATOM_REFS_INIT ("ATOM", Xatom_ATOM)
      ATOM_REFS_INIT ("ATOM_PAIR", Xatom_ATOM_PAIR)
      ATOM_REFS_INIT ("CLIPBOARD_MANAGER", Xatom_CLIPBOARD_MANAGER)
      ATOM_REFS_INIT ("_XEMBED_INFO", Xatom_XEMBED_INFO)
      /* For properties of font.  */
      ATOM_REFS_INIT ("PIXEL_SIZE", Xatom_PIXEL_SIZE)
      ATOM_REFS_INIT ("AVERAGE_WIDTH", Xatom_AVERAGE_WIDTH)
      ATOM_REFS_INIT ("_MULE_BASELINE_OFFSET", Xatom_MULE_BASELINE_OFFSET)
      ATOM_REFS_INIT ("_MULE_RELATIVE_COMPOSE", Xatom_MULE_RELATIVE_COMPOSE)
      ATOM_REFS_INIT ("_MULE_DEFAULT_ASCENT", Xatom_MULE_DEFAULT_ASCENT)
      /* Ghostscript support.  */
      ATOM_REFS_INIT ("DONE", Xatom_DONE)
      ATOM_REFS_INIT ("PAGE", Xatom_PAGE)
      ATOM_REFS_INIT ("SCROLLBAR", Xatom_Scrollbar)
      ATOM_REFS_INIT ("HORIZONTAL_SCROLLBAR", Xatom_Horizontal_Scrollbar)
      ATOM_REFS_INIT ("_XEMBED", Xatom_XEMBED)
      /* EWMH */
      ATOM_REFS_INIT ("_NET_WM_STATE", Xatom_net_wm_state)
      ATOM_REFS_INIT ("_NET_WM_STATE_FULLSCREEN", Xatom_net_wm_state_fullscreen)
      ATOM_REFS_INIT ("_NET_WM_STATE_MAXIMIZED_HORZ",
                      Xatom_net_wm_state_maximized_horz)
      ATOM_REFS_INIT ("_NET_WM_STATE_MAXIMIZED_VERT",
                      Xatom_net_wm_state_maximized_vert)
      ATOM_REFS_INIT ("_NET_WM_STATE_STICKY", Xatom_net_wm_state_sticky)
      ATOM_REFS_INIT ("_NET_WM_STATE_HIDDEN", Xatom_net_wm_state_hidden)
      ATOM_REFS_INIT ("_NET_WM_WINDOW_TYPE", Xatom_net_window_type)
      ATOM_REFS_INIT ("_NET_WM_WINDOW_TYPE_TOOLTIP",
                      Xatom_net_window_type_tooltip)
      ATOM_REFS_INIT ("_NET_WM_ICON_NAME", Xatom_net_wm_icon_name)
      ATOM_REFS_INIT ("_NET_WM_NAME", Xatom_net_wm_name)
      ATOM_REFS_INIT ("_NET_SUPPORTED",  Xatom_net_supported)
      ATOM_REFS_INIT ("_NET_SUPPORTING_WM_CHECK", Xatom_net_supporting_wm_check)
      ATOM_REFS_INIT ("_NET_WM_WINDOW_OPACITY", Xatom_net_wm_window_opacity)
      ATOM_REFS_INIT ("_NET_ACTIVE_WINDOW", Xatom_net_active_window)
      ATOM_REFS_INIT ("_NET_FRAME_EXTENTS", Xatom_net_frame_extents)
      ATOM_REFS_INIT ("_NET_CURRENT_DESKTOP", Xatom_net_current_desktop)
      ATOM_REFS_INIT ("_NET_WORKAREA", Xatom_net_workarea)
      /* Session management */
      ATOM_REFS_INIT ("SM_CLIENT_ID", Xatom_SM_CLIENT_ID)
      ATOM_REFS_INIT ("_XSETTINGS_SETTINGS", Xatom_xsettings_prop)
      ATOM_REFS_INIT ("MANAGER", Xatom_xsettings_mgr)
      ATOM_REFS_INIT ("_NET_WM_STATE_SKIP_TASKBAR", Xatom_net_wm_state_skip_taskbar)
      ATOM_REFS_INIT ("_NET_WM_STATE_ABOVE", Xatom_net_wm_state_above)
      ATOM_REFS_INIT ("_NET_WM_STATE_BELOW", Xatom_net_wm_state_below)
    };

    int i;
    enum { atom_count = ARRAYELTS (atom_refs) };
    /* 1 for _XSETTINGS_SN.  */
    enum { total_atom_count = 1 + atom_count };
    Atom atoms_return[total_atom_count];
    char *atom_names[total_atom_count];
    static char const xsettings_fmt[] = "_XSETTINGS_S%d";
    char xsettings_atom_name[sizeof xsettings_fmt - 2
                             + INT_STRLEN_BOUND (int)];

    for (i = 0; i < atom_count; i++)
      atom_names[i] = (char *) atom_refs[i].name;

    /* Build _XSETTINGS_SN atom name.  */
    sprintf (xsettings_atom_name, xsettings_fmt,
             XScreenNumberOfScreen (dpyinfo->screen));
    atom_names[i] = xsettings_atom_name;

    XInternAtoms (dpyinfo->display, atom_names, total_atom_count,
                  False, atoms_return);

    for (i = 0; i < atom_count; i++)
      *(Atom *) ((char *) dpyinfo + atom_refs[i].offset) = atoms_return[i];

    /* Manually copy last atom.  */
    dpyinfo->Xatom_xsettings_sel = atoms_return[i];
  }

  dpyinfo->x_dnd_atoms_size = 8;
  dpyinfo->x_dnd_atoms = xmalloc (sizeof *dpyinfo->x_dnd_atoms
                                  * dpyinfo->x_dnd_atoms_size);
  dpyinfo->gray
    = XCreatePixmapFromBitmapData (dpyinfo->display, dpyinfo->root_window,
                                   gray_bits, gray_width, gray_height,
                                   1, 0, 1);

  x_setup_pointer_blanking (dpyinfo);

#ifdef HAVE_X_I18N
  xim_initialize (dpyinfo, resource_name);
#endif

  xsettings_initialize (dpyinfo);

  /* This is only needed for distinguishing keyboard and process input.  */
  if (dpyinfo->connection != 0)
    add_keyboard_wait_descriptor (dpyinfo->connection);

#ifdef F_SETOWN
  fcntl (dpyinfo->connection, F_SETOWN, getpid ());
#endif /* ! defined (F_SETOWN) */

  if (interrupt_input)
    init_sigio (dpyinfo->connection);

#ifdef USE_LUCID
  {
    XrmValue d, fr, to;
    Font font;

    dpy = dpyinfo->display;
    d.addr = (XPointer)&dpy;
    d.size = sizeof (Display *);
    fr.addr = (char *) XtDefaultFont;
    fr.size = sizeof (XtDefaultFont);
    to.size = sizeof (Font *);
    to.addr = (XPointer)&font;
    x_catch_errors (dpy);
    if (!XtCallConverter (dpy, XtCvtStringToFont, &d, 1, &fr, &to, NULL))
      emacs_abort ();
    if (x_had_errors_p (dpy) || !XQueryFont (dpy, font))
      XrmPutLineResource (&xrdb, "Emacs.dialog.*.font: 9x15");
    /* Do not free XFontStruct returned by the above call to XQueryFont.
       This leads to X protocol errors at XtCloseDisplay (Bug#18403).  */
    x_uncatch_errors ();
  }
#endif

  /* See if we should run in synchronous mode.  This is useful
     for debugging X code.  */
  {
    AUTO_STRING (synchronous, "synchronous");
    AUTO_STRING (Synchronous, "Synchronous");
    Lisp_Object value = display_x_get_resource (dpyinfo, synchronous,
                                                Synchronous, Qnil, Qnil);
    if (STRINGP (value)
        && (!strcmp (SSDATA (value), "true")
            || !strcmp (SSDATA (value), "on")))
      XSynchronize (dpyinfo->display, True);
  }

  {
    AUTO_STRING (useXIM, "useXIM");
    AUTO_STRING (UseXIM, "UseXIM");
    Lisp_Object value = display_x_get_resource (dpyinfo, useXIM, UseXIM,
                                                Qnil, Qnil);
#ifdef USE_XIM
    if (STRINGP (value)
        && (!strcmp (SSDATA (value), "false")
            || !strcmp (SSDATA (value), "off")))
      use_xim = false;
#else
    if (STRINGP (value)
        && (!strcmp (SSDATA (value), "true")
            || !strcmp (SSDATA (value), "on")))
      use_xim = true;
#endif
  }

#ifdef HAVE_X_SM
  /* Only do this for the very first display in the Emacs session.
     Ignore X session management when Emacs was first started on a
     tty or started as a daemon.  */
  if (terminal->id == 1 && ! IS_DAEMON)
    x_session_initialize (dpyinfo);
#endif

#ifdef USE_CAIRO
  x_extension_initialize (dpyinfo);
#endif

  unblock_input ();

  return dpyinfo;
}
\f
/* Get rid of display DPYINFO, deleting all frames on it,
   and without sending any more commands to the X server.  */

static void
x_delete_display (struct x_display_info *dpyinfo)
{
  struct terminal *t;
  struct color_name_cache_entry *color_entry, *next_color_entry;

  /* Close all frames and delete the generic struct terminal for this
     X display.  */
  for (t = terminal_list; t; t = t->next_terminal)
    if (t->type == output_x_window && t->display_info.x == dpyinfo)
      {
#ifdef HAVE_X_SM
        /* Close X session management when we close its display.  */
        if (t->id == 1 && x_session_have_connection ())
          x_session_close ();
#endif
        delete_terminal (t);
        break;
      }

  if (next_noop_dpyinfo == dpyinfo)
    next_noop_dpyinfo = dpyinfo->next;

  if (x_display_list == dpyinfo)
    x_display_list = dpyinfo->next;
  else
    {
      struct x_display_info *tail;

      for (tail = x_display_list; tail; tail = tail->next)
        if (tail->next == dpyinfo)
          tail->next = tail->next->next;
    }

  for (color_entry = dpyinfo->color_names;
       color_entry;
       color_entry = next_color_entry)
    {
      next_color_entry = color_entry->next;
      xfree (color_entry->name);
      xfree (color_entry);
    }

  xfree (dpyinfo->x_id_name);
  xfree (dpyinfo->x_dnd_atoms);
  xfree (dpyinfo->color_cells);
  xfree (dpyinfo);
}

#ifdef USE_X_TOOLKIT

/* Atimer callback function for TIMER.  Called every 0.1s to process
   Xt timeouts, if needed.  We must avoid calling XtAppPending as
   much as possible because that function does an implicit XFlush
   that slows us down.  */

static void
x_process_timeouts (struct atimer *timer)
{
  block_input ();
  x_timeout_atimer_activated_flag = false;
  if (toolkit_scroll_bar_interaction || popup_activated ())
    {
      while (XtAppPending (Xt_app_con) & XtIMTimer)
        XtAppProcessEvent (Xt_app_con, XtIMTimer);
      /* Reactivate the atimer for next time.  */
      x_activate_timeout_atimer ();
    }
  unblock_input ();
}

/* Install an asynchronous timer that processes Xt timeout events
   every 0.1s as long as either `toolkit_scroll_bar_interaction' or
   `popup_activated_flag' (in xmenu.c) is set.  Make sure to call this
   function whenever these variables are set.  This is necessary
   because some widget sets use timeouts internally, for example the
   LessTif menu bar, or the Xaw3d scroll bar.  When Xt timeouts aren't
   processed, these widgets don't behave normally.  */

void
x_activate_timeout_atimer (void)
{
  block_input ();
  if (!x_timeout_atimer_activated_flag)
    {
      struct timespec interval = make_timespec (0, 100 * 1000 * 1000);
      start_atimer (ATIMER_RELATIVE, interval, x_process_timeouts, 0);
      x_timeout_atimer_activated_flag = true;
    }
  unblock_input ();
}

#endif /* USE_X_TOOLKIT */

\f
/* Set up use of X before we make the first connection.  */

static struct redisplay_interface x_redisplay_interface =
  {
    x_frame_parm_handlers,
    x_produce_glyphs,
    x_write_glyphs,
    x_insert_glyphs,
    x_clear_end_of_line,
    x_scroll_run,
    x_after_update_window_line,
    x_update_window_begin,
    x_update_window_end,
    x_flip_and_flush,
    x_clear_window_mouse_face,
    x_get_glyph_overhangs,
    x_fix_overlapping_area,
    x_draw_fringe_bitmap,
#ifdef USE_CAIRO
    x_cr_define_fringe_bitmap,
    x_cr_destroy_fringe_bitmap,
#else
    0, /* define_fringe_bitmap */
    0, /* destroy_fringe_bitmap */
#endif
    x_compute_glyph_string_overhangs,
    x_draw_glyph_string,
    x_define_frame_cursor,
    x_clear_frame_area,
    x_draw_window_cursor,
    x_draw_vertical_window_border,
    x_draw_window_divider,
    x_shift_glyphs_for_insert, /* Never called; see comment in function.  */
    x_show_hourglass,
    x_hide_hourglass
  };


/* This function is called when the last frame on a display is deleted. */
void
x_delete_terminal (struct terminal *terminal)
{
  struct x_display_info *dpyinfo = terminal->display_info.x;

  /* Protect against recursive calls.  delete_frame in
     delete_terminal calls us back when it deletes our last frame.  */
  if (!terminal->name)
    return;

  block_input ();
#ifdef HAVE_X_I18N
  /* We must close our connection to the XIM server before closing the
     X display.  */
  if (dpyinfo->xim)
    xim_close_dpy (dpyinfo);
#endif

  /* Normally, the display is available...  */
  if (dpyinfo->display)
    {
      x_destroy_all_bitmaps (dpyinfo);
      XSetCloseDownMode (dpyinfo->display, DestroyAll);

      /* Whether or not XCloseDisplay destroys the associated resource
         database depends on the version of libX11.  To avoid both
         crash and memory leak, we dissociate the database from the
         display and then destroy dpyinfo->xrdb ourselves.

         Unfortunately, the above strategy does not work in some
         situations due to a bug in newer versions of libX11: because
         XrmSetDatabase doesn't clear the flag XlibDisplayDfltRMDB if
         dpy->db is NULL, XCloseDisplay destroys the associated
         database whereas it has not been created by XGetDefault
         (Bug#21974 in freedesktop.org Bugzilla).  As a workaround, we
         don't destroy the database here in order to avoid the crash
         in the above situations for now, though that may cause memory
         leaks in other situations.  */
#if false
#ifdef HAVE_XRMSETDATABASE
      XrmSetDatabase (dpyinfo->display, NULL);
#else
      dpyinfo->display->db = NULL;
#endif
      /* We used to call XrmDestroyDatabase from x_delete_display, but
         some older versions of libX11 crash if we call it after
         closing all the displays.  */
      XrmDestroyDatabase (dpyinfo->xrdb);
#endif

#ifdef USE_GTK
      xg_display_close (dpyinfo->display);
#else
#ifdef USE_X_TOOLKIT
      XtCloseDisplay (dpyinfo->display);
#else
      XCloseDisplay (dpyinfo->display);
#endif
#endif /* ! USE_GTK */
      /* Do not close the connection here because it's already closed
         by X(t)CloseDisplay (Bug#18403).  */
      dpyinfo->display = NULL;
    }

  /* ...but if called from x_connection_closed, the display may already
     be closed and dpyinfo->display was set to 0 to indicate that.  Since
     X server is most likely gone, explicit close is the only reliable
     way to continue and avoid Bug#19147.  */
  else if (dpyinfo->connection >= 0)
    emacs_close (dpyinfo->connection);

  /* No more input on this descriptor.  */
  delete_keyboard_wait_descriptor (dpyinfo->connection);
  /* Mark as dead. */
  dpyinfo->connection = -1;

  x_delete_display (dpyinfo);
  unblock_input ();
}

/* Create a struct terminal, initialize it with the X11 specific
   functions and make DISPLAY->TERMINAL point to it.  */

static struct terminal *
x_create_terminal (struct x_display_info *dpyinfo)
{
  struct terminal *terminal;

  terminal = create_terminal (output_x_window, &x_redisplay_interface);

  terminal->display_info.x = dpyinfo;
  dpyinfo->terminal = terminal;

  /* kboard is initialized in x_term_init. */

  terminal->clear_frame_hook = x_clear_frame;
  terminal->ins_del_lines_hook = x_ins_del_lines;
  terminal->delete_glyphs_hook = x_delete_glyphs;
  terminal->ring_bell_hook = XTring_bell;
  terminal->toggle_invisible_pointer_hook = XTtoggle_invisible_pointer;
  terminal->update_begin_hook = x_update_begin;
  terminal->update_end_hook = x_update_end;
  terminal->read_socket_hook = XTread_socket;
  terminal->frame_up_to_date_hook = XTframe_up_to_date;
  terminal->buffer_flipping_unblocked_hook = XTbuffer_flipping_unblocked_hook;
  terminal->mouse_position_hook = XTmouse_position;
  terminal->frame_rehighlight_hook = XTframe_rehighlight;
  terminal->frame_raise_lower_hook = XTframe_raise_lower;
  terminal->fullscreen_hook = XTfullscreen_hook;
  terminal->menu_show_hook = x_menu_show;
#if defined (USE_X_TOOLKIT) || defined (USE_GTK)
  terminal->popup_dialog_hook = xw_popup_dialog;
#endif
  terminal->set_vertical_scroll_bar_hook = XTset_vertical_scroll_bar;
  terminal->set_horizontal_scroll_bar_hook = XTset_horizontal_scroll_bar;
  terminal->condemn_scroll_bars_hook = XTcondemn_scroll_bars;
  terminal->redeem_scroll_bar_hook = XTredeem_scroll_bar;
  terminal->judge_scroll_bars_hook = XTjudge_scroll_bars;
  terminal->delete_frame_hook = x_destroy_window;
  terminal->delete_terminal_hook = x_delete_terminal;
  /* Other hooks are NULL by default.  */

  return terminal;
}

static void
x_initialize (void)
{
  baud_rate = 19200;

  x_noop_count = 0;
  any_help_event_p = false;
  ignore_next_mouse_click_timeout = 0;

#ifdef USE_GTK
  current_count = -1;
#endif

  /* Try to use interrupt input; if we can't, then start polling.  */
  Fset_input_interrupt_mode (Qt);

#if THREADS_ENABLED
  /* This must be called before any other Xlib routines.  */
  if (XInitThreads () == 0)
    fprintf (stderr,
             "Warning: An error occurred initializing X11 thread support!\n");
#endif

#ifdef USE_X_TOOLKIT
  XtToolkitInitialize ();

  Xt_app_con = XtCreateApplicationContext ();

  /* Register a converter from strings to pixels, which uses
     Emacs' color allocation infrastructure.  */
  XtAppSetTypeConverter (Xt_app_con,
                         XtRString, XtRPixel, cvt_string_to_pixel,
                         cvt_string_to_pixel_args,
                         XtNumber (cvt_string_to_pixel_args),
                         XtCacheByDisplay, cvt_pixel_dtor);

  XtAppSetFallbackResources (Xt_app_con, Xt_default_resources);
#endif

#ifdef USE_TOOLKIT_SCROLL_BARS
#ifndef USE_GTK
  xaw3d_arrow_scroll = False;
  xaw3d_pick_top = True;
#endif
#endif

#ifdef USE_CAIRO
  x_cr_init_fringe (&x_redisplay_interface);
#endif

  /* Note that there is no real way portable across R3/R4 to get the
     original error handler.  */
  XSetErrorHandler (x_error_handler);
  XSetIOErrorHandler (x_io_error_quitter);
}

#ifdef USE_GTK
void
init_xterm (void)
{
  /* Emacs can handle only core input events, so make sure
     Gtk doesn't use Xinput or Xinput2 extensions.  */
  xputenv ("GDK_CORE_DEVICE_EVENTS=1");
}
#endif

void
syms_of_xterm (void)
{
  x_error_message = NULL;

  DEFSYM (Qvendor_specific_keysyms, "vendor-specific-keysyms");
  DEFSYM (Qlatin_1, "latin-1");

#ifdef USE_GTK
  xg_default_icon_file = build_pure_c_string ("icons/hicolor/scalable/apps/emacs.svg");
  staticpro (&xg_default_icon_file);

  DEFSYM (Qx_gtk_map_stock, "x-gtk-map-stock");
#endif

  DEFVAR_BOOL ("x-use-underline-position-properties",
               x_use_underline_position_properties,
     doc: /* Non-nil means make use of UNDERLINE_POSITION font properties.
A value of nil means ignore them.  If you encounter fonts with bogus
UNDERLINE_POSITION font properties, for example 7x13 on XFree prior
to 4.1, set this to nil.  You can also use `underline-minimum-offset'
to override the font's UNDERLINE_POSITION for small font display
sizes.  */);
  x_use_underline_position_properties = true;

  DEFVAR_BOOL ("x-underline-at-descent-line",
               x_underline_at_descent_line,
     doc: /* Non-nil means to draw the underline at the same place as the descent line.
A value of nil means to draw the underline according to the value of the
variable `x-use-underline-position-properties', which is usually at the
baseline level.  The default value is nil.  */);
  x_underline_at_descent_line = false;

  DEFVAR_BOOL ("x-mouse-click-focus-ignore-position",
               x_mouse_click_focus_ignore_position,
    doc: /* Non-nil means that a mouse click to focus a frame does not move point.
This variable is only used when the window manager requires that you
click on a frame to select it (give it focus).  In that case, a value
of nil, means that the selected window and cursor position changes to
reflect the mouse click position, while a non-nil value means that the
selected window or cursor position is preserved.  */);
  x_mouse_click_focus_ignore_position = false;

  DEFVAR_LISP ("x-toolkit-scroll-bars", Vx_toolkit_scroll_bars,
    doc: /* Which toolkit scroll bars Emacs uses, if any.
A value of nil means Emacs doesn't use toolkit scroll bars.
With the X Window system, the value is a symbol describing the
X toolkit.  Possible values are: gtk, motif, xaw, or xaw3d.
With MS Windows or Nextstep, the value is t.  */);
#ifdef USE_TOOLKIT_SCROLL_BARS
#ifdef USE_MOTIF
  Vx_toolkit_scroll_bars = intern_c_string ("motif");
#elif defined HAVE_XAW3D
  Vx_toolkit_scroll_bars = intern_c_string ("xaw3d");
#elif USE_GTK
  Vx_toolkit_scroll_bars = intern_c_string ("gtk");
#else
  Vx_toolkit_scroll_bars = intern_c_string ("xaw");
#endif
#else
  Vx_toolkit_scroll_bars = Qnil;
#endif

  DEFSYM (Qmodifier_value, "modifier-value");
  DEFSYM (Qctrl, "ctrl");
  Fput (Qctrl, Qmodifier_value, make_number (ctrl_modifier));
  DEFSYM (Qalt, "alt");
  Fput (Qalt, Qmodifier_value, make_number (alt_modifier));
  DEFSYM (Qhyper, "hyper");
  Fput (Qhyper, Qmodifier_value, make_number (hyper_modifier));
  DEFSYM (Qmeta, "meta");
  Fput (Qmeta, Qmodifier_value, make_number (meta_modifier));
  DEFSYM (Qsuper, "super");
  Fput (Qsuper, Qmodifier_value, make_number (super_modifier));

  DEFVAR_LISP ("x-ctrl-keysym", Vx_ctrl_keysym,
    doc: /* Which keys Emacs uses for the ctrl modifier.
This should be one of the symbols `ctrl', `alt', `hyper', `meta',
`super'.  For example, `ctrl' means use the Ctrl_L and Ctrl_R keysyms.
The default is nil, which is the same as `ctrl'.  */);
  Vx_ctrl_keysym = Qnil;

  DEFVAR_LISP ("x-alt-keysym", Vx_alt_keysym,
    doc: /* Which keys Emacs uses for the alt modifier.
This should be one of the symbols `ctrl', `alt', `hyper', `meta',
`super'.  For example, `alt' means use the Alt_L and Alt_R keysyms.
The default is nil, which is the same as `alt'.  */);
  Vx_alt_keysym = Qnil;

  DEFVAR_LISP ("x-hyper-keysym", Vx_hyper_keysym,
    doc: /* Which keys Emacs uses for the hyper modifier.
This should be one of the symbols `ctrl', `alt', `hyper', `meta',
`super'.  For example, `hyper' means use the Hyper_L and Hyper_R
keysyms.  The default is nil, which is the same as `hyper'.  */);
  Vx_hyper_keysym = Qnil;

  DEFVAR_LISP ("x-meta-keysym", Vx_meta_keysym,
    doc: /* Which keys Emacs uses for the meta modifier.
This should be one of the symbols `ctrl', `alt', `hyper', `meta',
`super'.  For example, `meta' means use the Meta_L and Meta_R keysyms.
The default is nil, which is the same as `meta'.  */);
  Vx_meta_keysym = Qnil;

  DEFVAR_LISP ("x-super-keysym", Vx_super_keysym,
    doc: /* Which keys Emacs uses for the super modifier.
This should be one of the symbols `ctrl', `alt', `hyper', `meta',
`super'.  For example, `super' means use the Super_L and Super_R
keysyms.  The default is nil, which is the same as `super'.  */);
  Vx_super_keysym = Qnil;

  DEFVAR_LISP ("x-keysym-table", Vx_keysym_table,
    doc: /* Hash table of character codes indexed by X keysym codes.  */);
  Vx_keysym_table = make_hash_table (hashtest_eql, 900,
                                     DEFAULT_REHASH_SIZE,
                                     DEFAULT_REHASH_THRESHOLD,
                                     Qnil, false);

  DEFVAR_BOOL ("x-frame-normalize-before-maximize",
               x_frame_normalize_before_maximize,
    doc: /* Non-nil means normalize frame before maximizing.
If this variable is t, Emacs first asks the window manager to give the
frame its normal size, and only then the final state, whenever changing
from a full-height, full-width or full-both state to the maximized one
or when changing from the maximized to the full-height or full-width
state.

Set this variable only if your window manager cannot handle the
transition between the various maximization states.  */);
  x_frame_normalize_before_maximize = false;

  DEFVAR_BOOL ("x-gtk-use-window-move", x_gtk_use_window_move,
    doc: /* Non-nil means rely on gtk_window_move to set frame positions.
If this variable is t (the default), the GTK build uses the function
gtk_window_move to set or store frame positions and disables some time
consuming frame position adjustments.  */);
  x_gtk_use_window_move = true;
}