src/termhooks.h

   1 /* Parameters and display hooks for terminal devices.
   2
   3 Copyright (C) 1985-1986, 1993-1994, 2001-2017 Free Software Foundation,
   4 Inc.
   5
   6 This file is part of GNU Emacs.
   7
   8 GNU Emacs is free software: you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation, either version 3 of the License, or (at
  11 your option) any later version.
  12
  13 GNU Emacs is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef EMACS_TERMHOOKS_H
  22 #define EMACS_TERMHOOKS_H
  23
  24 /* Miscellanea.   */
  25
  26 #include "lisp.h"
  27 #include "systime.h" /* for Time */
  28
  29 struct glyph;
  30
  31 INLINE_HEADER_BEGIN
  32
  33 enum scroll_bar_part {
  34   scroll_bar_nowhere,
  35   scroll_bar_above_handle,
  36   scroll_bar_handle,
  37   scroll_bar_below_handle,
  38   scroll_bar_up_arrow,
  39   scroll_bar_down_arrow,
  40   scroll_bar_to_top,
  41   scroll_bar_to_bottom,
  42   scroll_bar_end_scroll,
  43   scroll_bar_move_ratio,
  44   scroll_bar_before_handle,
  45   scroll_bar_horizontal_handle,
  46   scroll_bar_after_handle,
  47   scroll_bar_left_arrow,
  48   scroll_bar_right_arrow,
  49   scroll_bar_to_leftmost,
  50   scroll_bar_to_rightmost
  51 };
  52
  53 /* Output method of a terminal (and frames on this terminal, respectively).  */
  54
  55 enum output_method
  56 {
  57   output_initial,
  58   output_termcap,
  59   output_x_window,
  60   output_msdos_raw,
  61   output_w32,
  62   output_ns
  63 };
  64
  65 /* Input queue declarations and hooks.  */
  66
  67 enum event_kind
  68 {
  69   NO_EVENT,                     /* nothing happened.  This should never
  70                                    actually appear in the event queue.  */
  71
  72   ASCII_KEYSTROKE_EVENT,        /* The ASCII code is in .code, perhaps
  73                                    with modifiers applied.
  74                                    .modifiers holds the state of the
  75                                    modifier keys.
  76                                    .frame_or_window is the frame in
  77                                    which the key was typed.
  78                                    .timestamp gives a timestamp (in
  79                                    milliseconds) for the keystroke.  */
  80   MULTIBYTE_CHAR_KEYSTROKE_EVENT,       /* The multibyte char code is in .code,
  81                                    perhaps with modifiers applied.
  82                                    The others are the same as
  83                                    ASCII_KEYSTROKE_EVENT.  */
  84   NON_ASCII_KEYSTROKE_EVENT,    /* .code is a number identifying the
  85                                    function key.  A code N represents
  86                                    a key whose name is
  87                                    function_key_names[N]; function_key_names
  88                                    is a table in keyboard.c to which you
  89                                    should feel free to add missing keys.
  90                                    .modifiers holds the state of the
  91                                    modifier keys.
  92                                    .frame_or_window is the frame in
  93                                    which the key was typed.
  94                                    .timestamp gives a timestamp (in
  95                                    milliseconds) for the keystroke.  */
  96   TIMER_EVENT,                  /* A timer fired.  */
  97   MOUSE_CLICK_EVENT,            /* The button number is in .code; it must
  98                                    be >= 0 and < NUM_MOUSE_BUTTONS, defined
  99                                    below.
 100                                    .modifiers holds the state of the
 101                                    modifier keys.
 102                                    .x and .y give the mouse position,
 103                                    in characters, within the window.
 104                                    .frame_or_window gives the frame
 105                                    the mouse click occurred in.
 106                                    .timestamp gives a timestamp (in
 107                                    milliseconds) for the click.  */
 108   WHEEL_EVENT,                  /* A wheel event is generated by a
 109                                    wheel on a mouse (e.g., MS
 110                                    Intellimouse).
 111                                    .modifiers holds the rotate
 112                                    direction (up or down), and the
 113                                    state of the modifier keys.
 114                                    .x and .y give the mouse position,
 115                                    in characters, within the window.
 116                                    .frame_or_window gives the frame
 117                                    the wheel event occurred in.
 118                                    .timestamp gives a timestamp (in
 119                                    milliseconds) for the event.  */
 120   HORIZ_WHEEL_EVENT,            /* A wheel event generated by a second
 121                                    horizontal wheel that is present on some
 122                                    mice. See WHEEL_EVENT.  */
 123 #ifdef HAVE_NTGUI
 124   LANGUAGE_CHANGE_EVENT,        /* A LANGUAGE_CHANGE_EVENT is
 125                                    generated when HAVE_NTGUI or on Mac OS
 126                                    when the keyboard layout or input
 127                                    language is changed by the
 128                                    user.  */
 129 #endif
 130   SCROLL_BAR_CLICK_EVENT,       /* .code gives the number of the mouse button
 131                                    that was clicked.
 132                                    .modifiers holds the state of the modifier
 133                                    keys.
 134                                    .part is a lisp symbol indicating which
 135                                    part of the scroll bar got clicked.
 136                                    .x gives the distance from the start of the
 137                                    scroll bar of the click; .y gives the total
 138                                    length of the scroll bar.
 139                                    .frame_or_window gives the window
 140                                    whose scroll bar was clicked in.
 141                                    .timestamp gives a timestamp (in
 142                                    milliseconds) for the click.  */
 143   HORIZONTAL_SCROLL_BAR_CLICK_EVENT,    /* .code gives the number of the mouse button
 144                                    that was clicked.
 145                                    .modifiers holds the state of the modifier
 146                                    keys.
 147                                    .part is a lisp symbol indicating which
 148                                    part of the scroll bar got clicked.
 149                                    .x gives the distance from the start of the
 150                                    scroll bar of the click; .y gives the total
 151                                    length of the scroll bar.
 152                                    .frame_or_window gives the window
 153                                    whose scroll bar was clicked in.
 154                                    .timestamp gives a timestamp (in
 155                                    milliseconds) for the click.  */
 156   SELECTION_REQUEST_EVENT,      /* Another X client wants a selection from us.
 157                                    See `struct selection_input_event'.  */
 158   SELECTION_CLEAR_EVENT,        /* Another X client cleared our selection.  */
 159   BUFFER_SWITCH_EVENT,          /* A process filter has switched buffers.  */
 160   DELETE_WINDOW_EVENT,          /* An X client said "delete this window".  */
 161   MENU_BAR_EVENT,               /* An event generated by the menu bar.
 162                                    The frame_or_window field's cdr holds the
 163                                    Lisp-level event value.
 164                                    (Only the toolkit version uses these.)  */
 165   ICONIFY_EVENT,                /* An X client iconified this window.  */
 166   DEICONIFY_EVENT,              /* An X client deiconified this window.  */
 167   MENU_BAR_ACTIVATE_EVENT,      /* A button press in the menu bar
 168                                    (toolkit version only).  */
 169   DRAG_N_DROP_EVENT,            /* A drag-n-drop event is generated when
 170                                    files selected outside of Emacs are dropped
 171                                    onto an Emacs window.
 172                                    .modifiers holds the state of the
 173                                    modifier keys.
 174                                    .x and .y give the mouse position,
 175                                    in characters, within the window.
 176                                    .frame_or_window is the frame in
 177                                    which the drop was made.
 178                                    .arg is a platform-dependent
 179                                    representation of the dropped items.
 180                                    .timestamp gives a timestamp (in
 181                                    milliseconds) for the click.  */
 182   USER_SIGNAL_EVENT,            /* A user signal.
 183                                    code is a number identifying it,
 184                                    index into lispy_user_signals.  */
 185
 186   /* Help events.  Member `frame_or_window' of the input_event is the
 187      frame on which the event occurred, and member `arg' contains
 188      the help to show.  */
 189   HELP_EVENT,
 190
 191   /* An event from a tool-bar.  Member `arg' of the input event
 192      contains the tool-bar item selected.  If `frame_or_window'
 193      and `arg' are equal, this is a prefix event.  */
 194   TOOL_BAR_EVENT,
 195
 196   /* Queued from XTread_socket on FocusIn events.  Translated into
 197      `switch-frame' events in kbd_buffer_get_event, if necessary.  */
 198   FOCUS_IN_EVENT,
 199
 200   FOCUS_OUT_EVENT,
 201
 202   /* Generated when mouse moves over window not currently selected.  */
 203   SELECT_WINDOW_EVENT,
 204
 205   /* Queued from XTread_socket when session manager sends
 206      save yourself before shutdown. */
 207   SAVE_SESSION_EVENT
 208
 209 #ifdef HAVE_GPM
 210   , GPM_CLICK_EVENT
 211 #endif
 212
 213 #ifdef HAVE_DBUS
 214   , DBUS_EVENT
 215 #endif
 216
 217   , CONFIG_CHANGED_EVENT
 218
 219 #ifdef HAVE_NTGUI
 220   /* Generated when an APPCOMMAND event is received, in response to
 221      Multimedia or Internet buttons on some keyboards.
 222      Such keys are available as normal function keys on X through the
 223      Xkeyboard extension.
 224      On Windows, some of them get mapped to normal function key events,
 225      but others need to be handled by APPCOMMAND. Handling them all as
 226      APPCOMMAND events means they can be disabled
 227      (w32-pass-multimedia-buttons-to-system), important on Windows since
 228      the system never sees these keys if Emacs claims to handle them.
 229      On X, the window manager seems to grab the keys it wants
 230      first, so this is not a problem there.  */
 231   , MULTIMEDIA_KEY_EVENT
 232 #endif
 233
 234 #ifdef HAVE_NS
 235   /* Generated when native multi-keystroke input method is used to modify
 236      tentative or indicative text display. */
 237   , NS_TEXT_EVENT
 238   /* Non-key system events (e.g. application menu events) */
 239   , NS_NONKEY_EVENT
 240 #endif
 241
 242 #ifdef HAVE_XWIDGETS
 243   /* events generated by xwidgets*/
 244    , XWIDGET_EVENT
 245 #endif
 246
 247 #ifdef USE_FILE_NOTIFY
 248   /* File or directory was changed.  */
 249   , FILE_NOTIFY_EVENT
 250 #endif
 251
 252 };
 253
 254 /* Bit width of an enum event_kind tag at the start of structs and unions.  */
 255 enum { EVENT_KIND_WIDTH = 16 };
 256
 257 /* If a struct input_event has a kind which is SELECTION_REQUEST_EVENT
 258    or SELECTION_CLEAR_EVENT, then its contents are really described
 259    by `struct selection_input_event'; see xterm.h.  */
 260
 261 /* The keyboard input buffer is an array of these structures.  Each one
 262    represents some sort of input event - a keystroke, a mouse click, or
 263    a window system event.  These get turned into their lispy forms when
 264    they are removed from the event queue.  */
 265
 266 struct input_event
 267 {
 268   /* What kind of event was this?  */
 269   ENUM_BF (event_kind) kind : EVENT_KIND_WIDTH;
 270
 271   /* Used in scroll back click events.  */
 272   ENUM_BF (scroll_bar_part) part : 16;
 273
 274   /* For an ASCII_KEYSTROKE_EVENT and MULTIBYTE_CHAR_KEYSTROKE_EVENT,
 275      this is the character.
 276      For a NON_ASCII_KEYSTROKE_EVENT, this is the keysym code.
 277      For a mouse event, this is the button number.  */
 278   unsigned code;
 279
 280   /* See enum below for interpretation.  */
 281   unsigned modifiers;
 282
 283   /* One would prefer C integers, but HELP_EVENT uses these to
 284      record frame or window object and a help form, respectively.  */
 285   Lisp_Object x, y;
 286
 287   /* Usually a time as reported by window system-specific event loop.
 288      For a HELP_EVENT, this is the position within the object (stored
 289      in ARG below) where the help was found.  */
 290   Time timestamp;
 291
 292   /* This field is copied into a vector while the event is in
 293      the queue, so that garbage collections won't kill it.  */
 294   Lisp_Object frame_or_window;
 295
 296   /* This additional argument is used in attempt to avoid extra consing
 297      when building events.  Unfortunately some events have to pass much
 298      more data than it's reasonable to pack directly into this structure.  */
 299   Lisp_Object arg;
 300 };
 301
 302 #define EVENT_INIT(event) memset (&(event), 0, sizeof (struct input_event))
 303
 304 /* Bits in the modifiers member of the input_event structure.
 305    Note that reorder_modifiers assumes that the bits are in canonical
 306    order.
 307
 308    The modifiers applied to mouse clicks are rather ornate.  The
 309    window-system-specific code should store mouse clicks with
 310    up_modifier or down_modifier set.  Having an explicit down modifier
 311    simplifies some of window-system-independent code; without it, the
 312    code would have to recognize down events by checking if the event
 313    is a mouse click lacking the click and drag modifiers.
 314
 315    The window-system independent code turns all up_modifier events
 316    bits into drag_modifier, click_modifier, double_modifier, or
 317    triple_modifier events.  The click_modifier has no written
 318    representation in the names of the symbols used as event heads,
 319    but it does appear in the Qevent_symbol_components property of the
 320    event heads.  */
 321 enum {
 322   up_modifier   =   1,          /* Only used on mouse buttons - always
 323                                    turned into a click or a drag modifier
 324                                    before lisp code sees the event.  */
 325   down_modifier =   2,          /* Only used on mouse buttons.  */
 326   drag_modifier =   4,          /* This is never used in the event
 327                                    queue; it's only used internally by
 328                                    the window-system-independent code.  */
 329   click_modifier=   8,          /* See drag_modifier.  */
 330   double_modifier= 16,          /* See drag_modifier.  */
 331   triple_modifier= 32,          /* See drag_modifier.  */
 332
 333   /* The next four modifier bits are used also in keyboard events at
 334      the Lisp level.
 335
 336      It's probably not the greatest idea to use the 2^28 bit for any
 337      modifier.  It may or may not be the sign bit, depending on
 338      FIXNUM_BITS, so using it to represent a modifier key means that
 339      characters thus modified have different integer equivalents
 340      depending on the architecture they're running on.  Oh, and
 341      applying XINT to a character whose 2^28 bit is set might sign-extend
 342      it, so you get a bunch of bits in the mask you didn't want.
 343
 344      The CHAR_ macros are defined in lisp.h.  */
 345   alt_modifier  =  CHAR_ALT,    /* Under X, the XK_Alt_[LR] keysyms.  */
 346   super_modifier=  CHAR_SUPER,  /* Under X, the XK_Super_[LR] keysyms.  */
 347   hyper_modifier=  CHAR_HYPER,  /* Under X, the XK_Hyper_[LR] keysyms.  */
 348   shift_modifier=  CHAR_SHIFT,
 349   ctrl_modifier =  CHAR_CTL,
 350   meta_modifier =  CHAR_META    /* Under X, the XK_Meta_[LR] keysyms.  */
 351 };
 352
 353 #ifdef HAVE_GPM
 354 #include <gpm.h>
 355 extern int handle_one_term_event (struct tty_display_info *, Gpm_Event *, struct input_event *);
 356 #ifndef HAVE_WINDOW_SYSTEM
 357 extern void term_mouse_moveto (int, int);
 358 #endif
 359
 360 /* The device for which we have enabled gpm support.  */
 361 extern struct tty_display_info *gpm_tty;
 362 #endif
 363
 364 /* Terminal-local parameters. */
 365 struct terminal
 366 {
 367   /* This is for Lisp; the terminal code does not refer to it.  */
 368   struct vectorlike_header header;
 369
 370   /* Parameter alist of this terminal.  */
 371   Lisp_Object param_alist;
 372
 373   /* List of charsets supported by the terminal.  It is set by
 374      Fset_terminal_coding_system_internal along with
 375      the member terminal_coding.  */
 376   Lisp_Object charset_list;
 377
 378   /* This is an association list containing the X selections that
 379      Emacs might own on this terminal.  Each element has the form
 380        (SELECTION-NAME SELECTION-VALUE SELECTION-TIMESTAMP FRAME)
 381      SELECTION-NAME is a lisp symbol, whose name is the name of an X Atom.
 382      SELECTION-VALUE is the value that emacs owns for that selection.
 383       It may be any kind of Lisp object.
 384      SELECTION-TIMESTAMP is the time at which emacs began owning this
 385       selection, as a cons of two 16-bit numbers (making a 32 bit
 386       time.)
 387      FRAME is the frame for which we made the selection.  If there is
 388       an entry in this alist, then it can be assumed that Emacs owns
 389       that selection.
 390      The only (eq) parts of this list that are visible from Lisp are
 391     the selection-values.  */
 392   Lisp_Object Vselection_alist;
 393
 394   /* If a char-table, this maps characters to terminal glyph codes.
 395      If t, the mapping is not available.  If nil, it is not known
 396      whether the mapping is available.  */
 397   Lisp_Object glyph_code_table;
 398
 399   /* All fields before `next_terminal' should be Lisp_Object and are traced
 400      by the GC.  All fields afterwards are ignored by the GC.  */
 401
 402   /* Chain of all terminal devices. */
 403   struct terminal *next_terminal;
 404
 405   /* Unique id for this terminal device. */
 406   int id;
 407
 408   /* The number of frames that are on this terminal. */
 409   int reference_count;
 410
 411   /* The type of the terminal device. */
 412   enum output_method type;
 413
 414   /* The name of the terminal device.  Do not use this to uniquely
 415      identify a terminal; the same device may be opened multiple
 416      times. */
 417   char *name;
 418
 419   /* The terminal's keyboard object. */
 420   struct kboard *kboard;
 421
 422 #ifdef HAVE_WINDOW_SYSTEM
 423   /* Cache of images.  */
 424   struct image_cache *image_cache;
 425 #endif /* HAVE_WINDOW_SYSTEM */
 426
 427   /* Device-type dependent data shared amongst all frames on this terminal.  */
 428   union display_info
 429   {
 430     struct tty_display_info *tty;     /* termchar.h */
 431     struct x_display_info *x;         /* xterm.h */
 432     struct w32_display_info *w32;     /* w32term.h */
 433     struct ns_display_info *ns;       /* nsterm.h */
 434   } display_info;
 435
 436 \f
 437   /* Coding-system to be used for encoding terminal output.  This
 438      structure contains information of a coding-system specified by
 439      the function `set-terminal-coding-system'.  Also see
 440      `safe_terminal_coding' in coding.h.  */
 441   struct coding_system *terminal_coding;
 442
 443   /* Coding-system of what is sent from terminal keyboard.  This
 444      structure contains information of a coding-system specified by
 445      the function `set-keyboard-coding-system'.  */
 446   struct coding_system *keyboard_coding;
 447
 448   /* Window-based redisplay interface for this device (0 for tty
 449      devices). */
 450   struct redisplay_interface *rif;
 451
 452   /* Frame-based redisplay interface. */
 453
 454   /* Text display hooks.  */
 455
 456   void (*cursor_to_hook) (struct frame *f, int vpos, int hpos);
 457   void (*raw_cursor_to_hook) (struct frame *, int, int);
 458
 459   void (*clear_to_end_hook) (struct frame *);
 460   void (*clear_frame_hook) (struct frame *);
 461   void (*clear_end_of_line_hook) (struct frame *, int);
 462
 463   void (*ins_del_lines_hook) (struct frame *f, int, int);
 464
 465   void (*insert_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 466   void (*write_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 467   void (*delete_glyphs_hook) (struct frame *, int);
 468
 469   void (*ring_bell_hook) (struct frame *f);
 470   void (*toggle_invisible_pointer_hook) (struct frame *f, bool invisible);
 471
 472   void (*reset_terminal_modes_hook) (struct terminal *);
 473   void (*set_terminal_modes_hook) (struct terminal *);
 474
 475   void (*update_begin_hook) (struct frame *);
 476   void (*update_end_hook) (struct frame *);
 477   void (*set_terminal_window_hook) (struct frame *, int);
 478
 479   /* Multi-frame and mouse support hooks.  */
 480
 481   /* Return the current position of the mouse.
 482
 483      Set *f to the frame the mouse is in, or zero if the mouse is in no
 484      Emacs frame.  If it is set to zero, all the other arguments are
 485      garbage.
 486
 487      If the motion started in a scroll bar, set *bar_window to the
 488      scroll bar's window, *part to the part the mouse is currently over,
 489      *x to the position of the mouse along the scroll bar, and *y to the
 490      overall length of the scroll bar.
 491
 492      Otherwise, set *bar_window to Qnil, and *x and *y to the column and
 493      row of the character cell the mouse is over.
 494
 495      Set *time to the time the mouse was at the returned position.  */
 496   void (*mouse_position_hook) (struct frame **f, int,
 497                                Lisp_Object *bar_window,
 498                                enum scroll_bar_part *part,
 499                                Lisp_Object *x,
 500                                Lisp_Object *y,
 501                                Time *);
 502
 503   /* When a frame's focus redirection is changed, this hook tells the
 504      window system code to re-decide where to put the highlight.  Under
 505      X, this means that Emacs lies about where the focus is.  */
 506   void (*frame_rehighlight_hook) (struct frame *);
 507
 508   /* If we're displaying frames using a window system that can stack
 509      frames on top of each other, this hook allows you to bring a frame
 510      to the front, or bury it behind all the other windows.  If this
 511      hook is zero, that means the terminal we're displaying on doesn't
 512      support overlapping frames, so there's no need to raise or lower
 513      anything.
 514
 515      If RAISE_FLAG, F is brought to the front, before all other
 516      windows.  If !RAISE_FLAG, F is sent to the back, behind all other
 517      windows.  */
 518   void (*frame_raise_lower_hook) (struct frame *f, bool raise_flag);
 519
 520   /* If the value of the frame parameter changed, this hook is called.
 521      For example, if going from fullscreen to not fullscreen this hook
 522      may do something OS dependent, like extended window manager hints on X11.  */
 523   void (*fullscreen_hook) (struct frame *f);
 524
 525   /* This hook is called to display menus.  */
 526   Lisp_Object (*menu_show_hook) (struct frame *f, int x, int y, int menuflags,
 527                                  Lisp_Object title, const char **error_name);
 528
 529   /* This hook is called to display popup dialog.  */
 530   Lisp_Object (*popup_dialog_hook) (struct frame *f, Lisp_Object header,
 531                                     Lisp_Object contents);
 532
 533   /* Scroll bar hooks.  */
 534
 535   /* The representation of scroll bars is determined by the code which
 536      implements them, except for one thing: they must be represented by
 537      lisp objects.  This allows us to place references to them in
 538      Lisp_Windows without worrying about those references becoming
 539      dangling references when the scroll bar is destroyed.
 540
 541      The window-system-independent portion of Emacs just refers to
 542      scroll bars via their windows, and never looks inside the scroll bar
 543      representation; it always uses hook functions to do all the
 544      scroll bar manipulation it needs.
 545
 546      The `vertical_scroll_bar' field of a Lisp_Window refers to that
 547      window's scroll bar, or is nil if the window doesn't have a
 548      scroll bar.
 549
 550      The `scroll_bars' and `condemned_scroll_bars' fields of a Lisp_Frame
 551      are free for use by the scroll bar implementation in any way it sees
 552      fit.  They are marked by the garbage collector.  */
 553
 554
 555   /* Set the vertical scroll bar for WINDOW to have its upper left corner
 556      at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 557      indicate that we are displaying PORTION characters out of a total
 558      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 559      have a scroll bar, create one for it.  */
 560   void (*set_vertical_scroll_bar_hook) (struct window *window,
 561                                         int portion, int whole,
 562                                         int position);
 563
 564
 565   /* Set the horizontal scroll bar for WINDOW to have its upper left
 566      corner at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 567      indicate that we are displaying PORTION characters out of a total
 568      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 569      have a scroll bar, create one for it.  */
 570   void (*set_horizontal_scroll_bar_hook) (struct window *window,
 571                                           int portion, int whole,
 572                                           int position);
 573
 574
 575   /* The following three hooks are used when we're doing a thorough
 576      redisplay of the frame.  We don't explicitly know which scroll bars
 577      are going to be deleted, because keeping track of when windows go
 578      away is a real pain - can you say set-window-configuration?
 579      Instead, we just assert at the beginning of redisplay that *all*
 580      scroll bars are to be removed, and then save scroll bars from the
 581      fiery pit when we actually redisplay their window.  */
 582
 583   /* Arrange for all scroll bars on FRAME to be removed at the next call
 584      to `*judge_scroll_bars_hook'.  A scroll bar may be spared if
 585      `*redeem_scroll_bar_hook' is applied to its window before the judgment.
 586
 587      This should be applied to each frame each time its window tree is
 588      redisplayed, even if it is not displaying scroll bars at the moment;
 589      if the HAS_SCROLL_BARS flag has just been turned off, only calling
 590      this and the judge_scroll_bars_hook will get rid of them.
 591
 592      If non-zero, this hook should be safe to apply to any frame,
 593      whether or not it can support scroll bars, and whether or not it is
 594      currently displaying them.  */
 595   void (*condemn_scroll_bars_hook) (struct frame *frame);
 596
 597   /* Unmark WINDOW's scroll bar for deletion in this judgment cycle.
 598      Note that it's okay to redeem a scroll bar that is not condemned.  */
 599   void (*redeem_scroll_bar_hook) (struct window *window);
 600
 601   /* Remove all scroll bars on FRAME that haven't been saved since the
 602      last call to `*condemn_scroll_bars_hook'.
 603
 604      This should be applied to each frame after each time its window
 605      tree is redisplayed, even if it is not displaying scroll bars at the
 606      moment; if the HAS_SCROLL_BARS flag has just been turned off, only
 607      calling this and condemn_scroll_bars_hook will get rid of them.
 608
 609      If non-zero, this hook should be safe to apply to any frame,
 610      whether or not it can support scroll bars, and whether or not it is
 611      currently displaying them.  */
 612   void (*judge_scroll_bars_hook) (struct frame *FRAME);
 613
 614 \f
 615   /* Called to read input events.
 616
 617      TERMINAL indicates which terminal device to read from.  Input
 618      events should be read into HOLD_QUIT.
 619
 620      A positive return value indicates that that many input events
 621      were read into BUF.
 622      Zero means no events were immediately available.
 623      A value of -1 means a transient read error, while -2 indicates
 624      that the device was closed (hangup), and it should be deleted.  */
 625   int (*read_socket_hook) (struct terminal *terminal,
 626                            struct input_event *hold_quit);
 627
 628   /* Called when a frame's display becomes entirely up to date.  */
 629   void (*frame_up_to_date_hook) (struct frame *);
 630
 631 \f
 632   /* Called to delete the device-specific portions of a frame that is
 633      on this terminal device. */
 634   void (*delete_frame_hook) (struct frame *);
 635
 636   /* Called after the last frame on this terminal is deleted, or when
 637      the display device was closed (hangup).
 638
 639      If this is NULL, then the generic delete_terminal is called
 640      instead.  Otherwise the hook must call delete_terminal itself.
 641
 642      The hook must check for and close any live frames that are still
 643      on the terminal.  delete_frame ensures that there are no live
 644      frames on the terminal when it calls this hook, so infinite
 645      recursion is prevented.  */
 646   void (*delete_terminal_hook) (struct terminal *);
 647 };
 648
 649 /* Most code should use these functions to set Lisp fields in struct
 650    terminal.  */
 651 INLINE void
 652 tset_charset_list (struct terminal *t, Lisp_Object val)
 653 {
 654   t->charset_list = val;
 655 }
 656 INLINE void
 657 tset_selection_alist (struct terminal *t, Lisp_Object val)
 658 {
 659   t->Vselection_alist = val;
 660 }
 661
 662 /* Chain of all terminal devices currently in use.  */
 663 extern struct terminal *terminal_list;
 664
 665 #define FRAME_MUST_WRITE_SPACES(f) (FRAME_TTY (f)->must_write_spaces)
 666 #define FRAME_LINE_INS_DEL_OK(f) (FRAME_TTY (f)->line_ins_del_ok)
 667 #define FRAME_CHAR_INS_DEL_OK(f) (FRAME_TTY (f)->char_ins_del_ok)
 668 #define FRAME_SCROLL_REGION_OK(f) (FRAME_TTY (f)->scroll_region_ok)
 669 #define FRAME_SCROLL_REGION_COST(f) (FRAME_TTY (f)->scroll_region_cost)
 670 #define FRAME_MEMORY_BELOW_FRAME(f) (FRAME_TTY (f)->memory_below_frame)
 671
 672 #define FRAME_TERMINAL_CODING(f) ((f)->terminal->terminal_coding)
 673 #define FRAME_KEYBOARD_CODING(f) ((f)->terminal->keyboard_coding)
 674
 675 #define TERMINAL_TERMINAL_CODING(d) ((d)->terminal_coding)
 676 #define TERMINAL_KEYBOARD_CODING(d) ((d)->keyboard_coding)
 677
 678 #define FRAME_RIF(f) ((f)->terminal->rif)
 679
 680 #define FRAME_TERMINAL(f) ((f)->terminal)
 681
 682 /* Return true if the terminal device is not suspended.  */
 683 #define TERMINAL_ACTIVE_P(d)                                            \
 684   (((d)->type != output_termcap && (d)->type != output_msdos_raw)       \
 685    || (d)->display_info.tty->input)
 686
 687 /* Return font cache data for the specified terminal.  The historical
 688    name is grossly misleading, actually it is (NAME . FONT-LIST-CACHE).  */
 689 #if defined (HAVE_X_WINDOWS)
 690 #define TERMINAL_FONT_CACHE(t)                                          \
 691   (t->type == output_x_window ? t->display_info.x->name_list_element : Qnil)
 692 #elif defined (HAVE_NTGUI)
 693 #define TERMINAL_FONT_CACHE(t)                                          \
 694   (t->type == output_w32 ? t->display_info.w32->name_list_element : Qnil)
 695 #elif defined (HAVE_NS)
 696 #define TERMINAL_FONT_CACHE(t)                                          \
 697   (t->type == output_ns ? t->display_info.ns->name_list_element : Qnil)
 698 #endif
 699
 700 extern struct terminal *decode_live_terminal (Lisp_Object);
 701 extern struct terminal *decode_tty_terminal (Lisp_Object);
 702 extern struct terminal *get_named_terminal (const char *);
 703 extern struct terminal *create_terminal (enum output_method,
 704                                          struct redisplay_interface *);
 705 extern void delete_terminal (struct terminal *);
 706 extern Lisp_Object terminal_glyph_code (struct terminal *, int);
 707
 708 /* The initial terminal device, created by initial_term_init.  */
 709 extern struct terminal *initial_terminal;
 710
 711 extern unsigned char *encode_terminal_code (struct glyph *, int,
 712                                             struct coding_system *);
 713
 714 #ifdef HAVE_GPM
 715 extern void close_gpm (int gpm_fd);
 716 #endif
 717
 718 #ifdef WINDOWSNT
 719 extern int cursorX (struct tty_display_info *);
 720 extern int cursorY (struct tty_display_info *);
 721 #else
 722 #define cursorX(t)  curX(t)
 723 #define cursorY(t)  curY(t)
 724 #endif
 725
 726 INLINE_HEADER_END
 727
 728 #endif /* EMACS_TERMHOOKS_H */