src/window.h

   1 /* Window definitions for GNU Emacs.
   2    Copyright (C) 1985, 1986, 1993, 1995, 1997, 1998, 1999, 2000, 2001
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef WINDOW_H_INCLUDED
  23 #define WINDOW_H_INCLUDED
  24
  25 #include "dispextern.h"
  26
  27 /* Windows are allocated as if they were vectors, but then the
  28 Lisp data type is changed to Lisp_Window.  They are garbage
  29 collected along with the vectors.
  30
  31 All windows in use are arranged into a tree, with pointers up and down.
  32
  33 Windows that are leaves of the tree are actually displayed
  34 and show the contents of buffers.  Windows that are not leaves
  35 are used for representing the way groups of leaf windows are
  36 arranged on the frame.  Leaf windows never become non-leaves.
  37 They are deleted only by calling delete-window on them (but
  38 this can be done implicitly).  Combination windows can be created
  39 and deleted at any time.
  40
  41 A leaf window has a non-nil buffer field, and also
  42  has markers in its start and pointm fields.  Non-leaf windows
  43  have nil in these fields.
  44
  45 Non-leaf windows are either vertical or horizontal combinations.
  46
  47 A vertical combination window has children that are arranged on the frame
  48 one above the next.  Its vchild field points to the uppermost child.
  49 The parent field of each of the children points to the vertical
  50 combination window.  The next field of each child points to the
  51 child below it, or is nil for the lowest child.  The prev field
  52 of each child points to the child above it, or is nil for the
  53 highest child.
  54
  55 A horizontal combination window has children that are side by side.
  56 Its hchild field points to the leftmost child.  In each child
  57 the next field points to the child to the right and the prev field
  58 points to the child to the left.
  59
  60 The children of a vertical combination window may be leaf windows
  61 or horizontal combination windows.  The children of a horizontal
  62 combination window may be leaf windows or vertical combination windows.
  63
  64 At the top of the tree are two windows which have nil as parent.
  65 The second of these is minibuf_window.  The first one manages all
  66 the frame area that is not minibuffer, and is called the root window.
  67 Different windows can be the root at different times;
  68 initially the root window is a leaf window, but if more windows
  69 are created then that leaf window ceases to be root and a newly
  70 made combination window becomes root instead.
  71
  72 In any case, on screens which have an ordinary window and a
  73 minibuffer, prev of the minibuf window is the root window and next of
  74 the root window is the minibuf window.  On minibufferless screens or
  75 minibuffer-only screens, the root window and the minibuffer window are
  76 one and the same, so its prev and next members are nil.
  77
  78 A dead window has its buffer, hchild, and vchild windows all nil.  */
  79
  80 struct cursor_pos
  81 {
  82   /* Pixel position.  These are always window relative.  */
  83   int x, y;
  84
  85   /* Glyph matrix position.  */
  86   int hpos, vpos;
  87 };
  88
  89 struct window
  90   {
  91     /* The first two fields are really the header of a vector */
  92     /* The window code does not refer to them.  */
  93     EMACS_INT size;
  94     struct Lisp_Vector *vec_next;
  95     /* The frame this window is on.  */
  96     Lisp_Object frame;
  97     /* t if this window is a minibuffer window.  */
  98     Lisp_Object mini_p;
  99     /* Following child (to right or down) at same level of tree */
 100     Lisp_Object next;
 101     /* Preceding child (to left or up) at same level of tree */
 102     Lisp_Object prev;
 103     /* First child of this window. */
 104     /* vchild is used if this is a vertical combination,
 105        hchild if this is a horizontal combination. */
 106     Lisp_Object hchild, vchild;
 107     /* The window this one is a child of. */
 108     Lisp_Object parent;
 109     /* The upper left corner coordinates of this window,
 110        as integers relative to upper left corner of frame = 0, 0 */
 111     Lisp_Object left;
 112     Lisp_Object top;
 113     /* The size of the window */
 114     Lisp_Object height;
 115     Lisp_Object width;
 116     /* The buffer displayed in this window */
 117     /* Of the fields vchild, hchild and buffer, only one is non-nil.  */
 118     Lisp_Object buffer;
 119     /* A marker pointing to where in the text to start displaying */
 120     Lisp_Object start;
 121     /* A marker pointing to where in the text point is in this window,
 122        used only when the window is not selected.
 123        This exists so that when multiple windows show one buffer
 124        each one can have its own value of point.  */
 125     Lisp_Object pointm;
 126     /* Non-nil means next redisplay must use the value of start
 127        set up for it in advance.  Set by scrolling commands.  */
 128     Lisp_Object force_start;
 129     /* Non-nil means we have explicitly changed the value of start,
 130        but that the next redisplay is not obliged to use the new value.
 131        This is used in Fdelete_other_windows to force a call to
 132        Vwindow_scroll_functions.  */
 133     Lisp_Object optional_new_start;
 134     /* Number of columns display within the window is scrolled to the left.  */
 135     Lisp_Object hscroll;
 136     /* Minimum hscroll for automatic hscrolling.  This is the value
 137        the user has set, by set-window-hscroll for example.  */
 138     Lisp_Object min_hscroll;
 139     /* Number saying how recently window was selected */
 140     Lisp_Object use_time;
 141     /* Unique number of window assigned when it was created */
 142     Lisp_Object sequence_number;
 143     /* No permanent meaning; used by save-window-excursion's bookkeeping */
 144     Lisp_Object temslot;
 145     /* text.modified of displayed buffer as of last time display completed */
 146     Lisp_Object last_modified;
 147     /* BUF_OVERLAY_MODIFIED of displayed buffer as of last complete update.  */
 148     Lisp_Object last_overlay_modified;
 149     /* Value of point at that time */
 150     Lisp_Object last_point;
 151     /* Non-nil if the buffer was "modified" when the window
 152        was last updated.  */
 153     Lisp_Object last_had_star;
 154     /* This window's vertical scroll bar.  This field is only for use
 155        by the window-system-dependent code which implements the
 156        scroll bars; it can store anything it likes here.  If this
 157        window is newly created and we haven't displayed a scroll bar in
 158        it yet, or if the frame doesn't have any scroll bars, this is nil.  */
 159     Lisp_Object vertical_scroll_bar;
 160
 161     /* Width of left and right marginal areas.  A value of nil means
 162        no margin.  */
 163     Lisp_Object left_margin_width;
 164     Lisp_Object right_margin_width;
 165
 166 /* The rest are currently not used or only half used */
 167     /* Frame coords of mark as of last time display completed */
 168     /* May be nil if mark does not exist or was not on frame */
 169     Lisp_Object last_mark_x;
 170     Lisp_Object last_mark_y;
 171     /* Z - the buffer position of the last glyph in the current matrix
 172        of W.  Only valid if WINDOW_END_VALID is not nil.  */
 173     Lisp_Object window_end_pos;
 174     /* Glyph matrix row of the last glyph in the current matrix
 175        of W.  Only valid if WINDOW_END_VALID is not nil.  */
 176     Lisp_Object window_end_vpos;
 177     /* t if window_end_pos is truly valid.
 178        This is nil if nontrivial redisplay is preempted
 179        since in that case the frame image that window_end_pos
 180        did not get onto the frame.  */
 181     Lisp_Object window_end_valid;
 182     /* Non-nil means must regenerate mode line of this window */
 183     Lisp_Object update_mode_line;
 184     /* Non-nil means current value of `start'
 185        was the beginning of a line when it was chosen.  */
 186     Lisp_Object start_at_line_beg;
 187     /* Display-table to use for displaying chars in this window.
 188        Nil means use the buffer's own display-table.  */
 189     Lisp_Object display_table;
 190     /* Non-nil means window is marked as dedicated.  */
 191     Lisp_Object dedicated;
 192     /* Line number and position of a line somewhere above the
 193        top of the screen.  */
 194     /* If this field is nil, it means we don't have a base line.  */
 195     Lisp_Object base_line_number;
 196     /* If this field is nil, it means we don't have a base line.
 197        If it is a buffer, it means don't display the line number
 198        as long as the window shows that buffer.  */
 199     Lisp_Object base_line_pos;
 200     /* If we have highlighted the region (or any part of it),
 201        this is the mark position that we used, as an integer.  */
 202     Lisp_Object region_showing;
 203     /* The column number currently displayed in this window's mode line,
 204        or nil if column numbers are not being displayed.  */
 205     Lisp_Object column_number_displayed;
 206     /* If redisplay in this window goes beyond this buffer position,
 207        must run the redisplay-end-trigger-hook.  */
 208     Lisp_Object redisplay_end_trigger;
 209     /* Non-nil means don't delete this window for becoming "too small".  */
 210     Lisp_Object too_small_ok;
 211
 212     /* Original window height and top before mini-window was
 213        enlarged. */
 214     Lisp_Object orig_height, orig_top;
 215
 216     /* No Lisp data may follow below this point without changing
 217        mark_object in alloc.c.  The member current_matrix must be the
 218        first non-Lisp member.  */
 219
 220     /* Glyph matrices.  */
 221     struct glyph_matrix *current_matrix;
 222     struct glyph_matrix *desired_matrix;
 223
 224     /* Cursor position as of last update that completed without
 225        pause.  This is the position of last_point.  */
 226     struct cursor_pos last_cursor;
 227
 228     /* Intended cursor position.   This is a position within the
 229        glyph matrix.  */
 230     struct cursor_pos cursor;
 231
 232     /* Where the cursor actually is.  */
 233     struct cursor_pos phys_cursor;
 234
 235     /* Cursor type last drawn on the window.  Used for X frames; -1
 236        initially.  */
 237     int phys_cursor_type;
 238
 239     /* This is handy for undrawing the cursor.  */
 240     int phys_cursor_ascent, phys_cursor_height;
 241
 242     /* Non-zero means the cursor is currently displayed.  This can be
 243        set to zero by functions overpainting the cursor image.  */
 244     unsigned phys_cursor_on_p : 1;
 245
 246     /* 0 means cursor is logically on, 1 means it's off.  Used for
 247        blinking cursor.  */
 248     unsigned cursor_off_p : 1;
 249
 250     /* Value of cursor_off_p as of the last redisplay.  */
 251     unsigned last_cursor_off_p : 1;
 252
 253     /* 1 means desired matrix has been build and window must be
 254        updated in update_frame.  */
 255     unsigned must_be_updated_p : 1;
 256
 257     /* Flag indicating that this window is not a real one.
 258        Currently only used for menu bar windows of frames.  */
 259     unsigned pseudo_window_p : 1;
 260
 261     /* Amount by which lines of this window are scrolled in
 262        y-direction (smooth scrolling).  */
 263     int vscroll;
 264
 265     /* Z_BYTE - the buffer position of the last glyph in the current matrix
 266        of W.  Only valid if WINDOW_END_VALID is not nil.  */
 267     int window_end_bytepos;
 268
 269     /* 1 means the window start of this window is frozen and may not
 270        be changed during redisplay.  If point is not in the window,
 271        accept that.  */
 272     unsigned frozen_window_start_p : 1;
 273
 274     /* 1 means that this window's height is temporarily fixed.  Used
 275        in resize_mini_window to precent resizing selected_window, if
 276        possible.  */
 277     unsigned height_fixed_p : 1;
 278 };
 279
 280 /* 1 if W is a minibuffer window.  */
 281
 282 #define MINI_WINDOW_P(W)        (!NILP ((W)->mini_p))
 283
 284 /* Return the window column at which the text in window W starts.
 285    This is different from the `left' field because it does not include
 286    a left-hand scroll bar if any.  */
 287
 288 #define WINDOW_LEFT_MARGIN(W) \
 289      (XFASTINT ((W)->left) \
 290       + FRAME_LEFT_SCROLL_BAR_WIDTH (XFRAME (WINDOW_FRAME (W))))
 291
 292 /* Return the window column before which window W ends.
 293    This includes a right-hand scroll bar, if any.  */
 294
 295 #define WINDOW_RIGHT_EDGE(W) \
 296      (XFASTINT ((W)->left) + XFASTINT ((W)->width))
 297
 298 /* Return the window column before which the text in window W ends.
 299    This is different from WINDOW_RIGHT_EDGE because it does not include
 300    a scroll bar or window-separating line on the right edge.  */
 301
 302 #define WINDOW_RIGHT_MARGIN(W) \
 303      (WINDOW_RIGHT_EDGE (W) \
 304       - (FRAME_HAS_VERTICAL_SCROLL_BARS_ON_RIGHT (XFRAME (WINDOW_FRAME (W))) \
 305          ? FRAME_SCROLL_BAR_COLS (XFRAME (WINDOW_FRAME (W))) \
 306          : 0))
 307
 308 /* 1 if window W takes up the full width of its frame.  */
 309
 310 #define WINDOW_FULL_WIDTH_P(W) \
 311      (XFASTINT ((W)->width) == FRAME_WINDOW_WIDTH (XFRAME (WINDOW_FRAME (W))))
 312
 313 /* 1 if window W's has no other windows to its right in its frame.  */
 314
 315 #define WINDOW_RIGHTMOST_P(W) \
 316      (WINDOW_RIGHT_EDGE (W) == FRAME_WINDOW_WIDTH (XFRAME (WINDOW_FRAME (W))))
 317
 318
 319 /* This is the window in which the terminal's cursor should
 320    be left when nothing is being done with it.  This must
 321    always be a leaf window, and its buffer is selected by
 322    the top level editing loop at the end of each command.
 323
 324    This value is always the same as
 325     FRAME_SELECTED_WINDOW (selected_frame).  */
 326
 327 extern Lisp_Object selected_window;
 328
 329 /* This is a time stamp for window selection, so we can find the least
 330    recently used window.  Its only users are Fselect_window,
 331    init_window_once, and make_frame.  */
 332
 333 extern int window_select_count;
 334
 335 /* The minibuffer window of the selected frame.
 336    Note that you cannot test for minibufferness of an arbitrary window
 337    by comparing against this; use the MINI_WINDOW_P macro instead.  */
 338
 339 extern Lisp_Object minibuf_window;
 340
 341 /* Non-nil means it is the window whose mode line should be
 342    shown as the selected window when the minibuffer is selected.  */
 343
 344 extern Lisp_Object Vminibuf_selected_window;
 345
 346 /* Non-nil => window to for C-M-v to scroll when the minibuffer is
 347    selected.  */
 348
 349 extern Lisp_Object Vminibuf_scroll_window;
 350
 351 /* Nil or a symbol naming the window system under which emacs is
 352    running ('x is the only current possibility) */
 353
 354 extern Lisp_Object Vwindow_system;
 355
 356 /* Version number of X windows: 10, 11 or nil.  */
 357
 358 extern Lisp_Object Vwindow_system_version;
 359
 360 /* Window that the mouse is over (nil if no mouse support).  */
 361
 362 extern Lisp_Object Vmouse_window;
 363
 364 /* Last mouse-click event (nil if no mouse support).  */
 365
 366 extern Lisp_Object Vmouse_event;
 367
 368 EXFUN (Fnext_window, 3);
 369 EXFUN (Fselect_window, 1);
 370 EXFUN (Fdisplay_buffer, 3);
 371 EXFUN (Fset_window_buffer, 2);
 372 EXFUN (Fset_window_hscroll, 2);
 373 EXFUN (Fwindow_hscroll, 1);
 374 EXFUN (Fset_window_vscroll, 2);
 375 EXFUN (Fwindow_vscroll, 1);
 376 EXFUN (Fset_window_margins, 3);
 377 EXFUN (Fwindow_live_p, 1);
 378 EXFUN (Fset_window_point, 2);
 379 extern Lisp_Object make_window P_ ((void));
 380 extern void delete_window P_ ((Lisp_Object));
 381 extern Lisp_Object window_from_coordinates P_ ((struct frame *, int, int, int *, int));
 382 EXFUN (Fwindow_dedicated_p, 1);
 383 extern int window_height P_ ((Lisp_Object));
 384 extern int window_width P_ ((Lisp_Object));
 385 extern void set_window_height P_ ((Lisp_Object, int, int));
 386 extern void set_window_width P_ ((Lisp_Object, int, int));
 387 extern void delete_all_subwindows P_ ((struct window *));
 388 extern void freeze_window_starts P_ ((struct frame *, int));
 389 extern void foreach_window P_ ((struct frame *,
 390                                 int (* fn) (struct window *, void *),
 391                                 void *));
 392 extern void grow_mini_window P_ ((struct window *, int));
 393 extern void shrink_mini_window P_ ((struct window *));
 394
 395
 396 /* Make WINDOW display BUFFER as its contents.  RUN_HOOKS_P non-zero
 397    means it's allowed to run hooks.  See make_frame for a case where
 398    it's not allowed.  */
 399
 400 void set_window_buffer P_ ((Lisp_Object window, Lisp_Object buffer,
 401                             int run_hooks_p));
 402
 403 /* Prompt to display in front of the minibuffer contents.  */
 404
 405 extern Lisp_Object minibuf_prompt;
 406
 407 /* The visual width of the above.  */
 408
 409 extern int minibuf_prompt_width;
 410
 411 /* This is the window where the echo area message was displayed.  It
 412    is always a minibuffer window, but it may not be the same window
 413    currently active as a minibuffer.  */
 414
 415 extern Lisp_Object echo_area_window;
 416
 417 /* Depth in recursive edits.  */
 418
 419 extern int command_loop_level;
 420
 421 /* Depth in minibuffer invocations.  */
 422
 423 extern int minibuf_level;
 424
 425 /* true iff we should redraw the mode lines on the next redisplay.  */
 426
 427 extern int update_mode_lines;
 428
 429 /* Nonzero if BEGV - BEG or Z - ZV of current buffer has changed since
 430    last redisplay that finished.  */
 431
 432 extern int clip_changed;
 433
 434 /* Nonzero if window sizes or contents have changed since last
 435    redisplay that finished */
 436
 437 extern int windows_or_buffers_changed;
 438
 439 /* Number of windows displaying the selected buffer.  Normally this is
 440    1, but it can be more.  */
 441
 442 extern int buffer_shared;
 443
 444 /* If *ROWS or *COLS are too small a size for FRAME, set them to the
 445    minimum allowable size.  */
 446
 447 extern void check_frame_size P_ ((struct frame *frame, int *rows, int *cols));
 448
 449 /* Return a pointer to the glyph W's physical cursor is on.  Value is
 450    null if W's current matrix is invalid, so that no meaningfull glyph
 451    can be returned.  */
 452
 453 struct glyph *get_phys_cursor_glyph P_ ((struct window *w));
 454
 455 /* Value is non-zero if WINDOW is a live window.  */
 456
 457 #define WINDOW_LIVE_P(WINDOW) \
 458      (WINDOWP ((WINDOW)) && !NILP (XWINDOW ((WINDOW))->buffer))
 459
 460 #endif /* not WINDOW_H_INCLUDED */