src/termhooks.h

   1 /* Parameters and display hooks for terminal devices.
   2    Copyright (C) 1985, 1986, 1993, 1994, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007, 2008  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 3 of the License, or
  10 (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 \f
  21 /* Miscellanea.   */
  22
  23 struct glyph;
  24 struct frame;
  25 \f
  26
  27 enum scroll_bar_part {
  28   scroll_bar_above_handle,
  29   scroll_bar_handle,
  30   scroll_bar_below_handle,
  31   scroll_bar_up_arrow,
  32   scroll_bar_down_arrow,
  33   scroll_bar_to_top,
  34   scroll_bar_to_bottom,
  35   scroll_bar_end_scroll,
  36   scroll_bar_move_ratio
  37 };
  38
  39 /* If the value of the frame parameter changed, whis hook is called.
  40    For example, if going from fullscreen to not fullscreen this hook
  41    may do something OS dependent, like extended window manager hints on X11.  */
  42 extern void (*fullscreen_hook) P_ ((struct frame *f));
  43
  44 \f
  45 /* Input queue declarations and hooks.  */
  46
  47 /* Expedient hack: only provide the below definitions to files that
  48    are prepared to handle lispy things.  CONSP is defined if lisp.h
  49    has been included before this file.  */
  50 #ifdef CONSP
  51
  52 enum event_kind
  53 {
  54   NO_EVENT,                     /* nothing happened.  This should never
  55                                    actually appear in the event queue.  */
  56
  57   ASCII_KEYSTROKE_EVENT,        /* The ASCII code is in .code, perhaps
  58                                    with modifiers applied.
  59                                    .modifiers holds the state of the
  60                                    modifier keys.
  61                                    .frame_or_window is the frame in
  62                                    which the key was typed.
  63                                    .timestamp gives a timestamp (in
  64                                    milliseconds) for the keystroke.  */
  65   MULTIBYTE_CHAR_KEYSTROKE_EVENT,       /* The multibyte char code is in .code,
  66                                    perhaps with modifiers applied.
  67                                    The others are the same as
  68                                    ASCII_KEYSTROKE_EVENT.  */
  69   NON_ASCII_KEYSTROKE_EVENT,    /* .code is a number identifying the
  70                                    function key.  A code N represents
  71                                    a key whose name is
  72                                    function_key_names[N]; function_key_names
  73                                    is a table in keyboard.c to which you
  74                                    should feel free to add missing keys.
  75                                    .modifiers holds the state of the
  76                                    modifier keys.
  77                                    .frame_or_window is the frame in
  78                                    which the key was typed.
  79                                    .timestamp gives a timestamp (in
  80                                    milliseconds) for the keystroke.  */
  81   TIMER_EVENT,                  /* A timer fired.  */
  82   MOUSE_CLICK_EVENT,            /* The button number is in .code; it must
  83                                    be >= 0 and < NUM_MOUSE_BUTTONS, defined
  84                                    below.
  85                                    .modifiers holds the state of the
  86                                    modifier keys.
  87                                    .x and .y give the mouse position,
  88                                    in characters, within the window.
  89                                    .frame_or_window gives the frame
  90                                    the mouse click occurred in.
  91                                    .timestamp gives a timestamp (in
  92                                    milliseconds) for the click.  */
  93   WHEEL_EVENT,                  /* A wheel event is generated by a
  94                                    wheel on a mouse (e.g., MS
  95                                    Intellimouse).
  96                                    .modifiers holds the rotate
  97                                    direction (up or down), and the
  98                                    state of the modifier keys.
  99                                    .x and .y give the mouse position,
 100                                    in characters, within the window.
 101                                    .frame_or_window gives the frame
 102                                    the wheel event occurred in.
 103                                    .timestamp gives a timestamp (in
 104                                    milliseconds) for the event.  */
 105   HORIZ_WHEEL_EVENT,            /* A wheel event generated by a second
 106                                    horizontal wheel that is present on some
 107                                    mice. See WHEEL_EVENT.  */
 108 #if defined (WINDOWSNT)
 109   LANGUAGE_CHANGE_EVENT,        /* A LANGUAGE_CHANGE_EVENT is
 110                                    generated on WINDOWSNT or Mac OS
 111                                    when the keyboard layout or input
 112                                    language is changed by the
 113                                    user.  */
 114 #endif
 115   SCROLL_BAR_CLICK_EVENT,       /* .code gives the number of the mouse button
 116                                    that was clicked.
 117                                    .modifiers holds the state of the modifier
 118                                    keys.
 119                                    .part is a lisp symbol indicating which
 120                                    part of the scroll bar got clicked.
 121                                    .x gives the distance from the start of the
 122                                    scroll bar of the click; .y gives the total
 123                                    length of the scroll bar.
 124                                    .frame_or_window gives the window
 125                                    whose scroll bar was clicked in.
 126                                    .timestamp gives a timestamp (in
 127                                    milliseconds) for the click.  */
 128   SELECTION_REQUEST_EVENT,      /* Another X client wants a selection from us.
 129                                    See `struct selection_input_event'.  */
 130   SELECTION_CLEAR_EVENT,        /* Another X client cleared our selection.  */
 131   BUFFER_SWITCH_EVENT,          /* A process filter has switched buffers.  */
 132   DELETE_WINDOW_EVENT,          /* An X client said "delete this window".  */
 133   MENU_BAR_EVENT,               /* An event generated by the menu bar.
 134                                    The frame_or_window field's cdr holds the
 135                                    Lisp-level event value.
 136                                    (Only the toolkit version uses these.)  */
 137   ICONIFY_EVENT,                /* An X client iconified this window.  */
 138   DEICONIFY_EVENT,              /* An X client deiconified this window.  */
 139   MENU_BAR_ACTIVATE_EVENT,      /* A button press in the menu bar
 140                                    (toolkit version only).  */
 141   DRAG_N_DROP_EVENT,            /* A drag-n-drop event is generated when
 142                                    files selected outside of Emacs are dropped
 143                                    onto an Emacs window.
 144                                    .modifiers holds the state of the
 145                                    modifier keys.
 146                                    .x and .y give the mouse position,
 147                                    in characters, within the window.
 148                                    .frame_or_window is the frame in
 149                                    which the drop was made.
 150                                    .arg is a platform-dependent
 151                                    representation of the dropped items.
 152                                    .timestamp gives a timestamp (in
 153                                    milliseconds) for the click.  */
 154   USER_SIGNAL_EVENT,            /* A user signal.
 155                                    code is a number identifying it,
 156                                    index into lispy_user_signals.  */
 157
 158   /* Help events.  Member `frame_or_window' of the input_event is the
 159      frame on which the event occurred, and member `arg' contains
 160      the help to show.  */
 161   HELP_EVENT,
 162
 163   /* An event from a tool-bar.  Member `arg' of the input event
 164      contains the tool-bar item selected.  If `frame_or_window'
 165      and `arg' are equal, this is a prefix event.  */
 166   TOOL_BAR_EVENT,
 167
 168   /* Queued from XTread_socket on FocusIn events.  Translated into
 169      `switch-frame' events in kbd_buffer_get_event, if necessary.  */
 170   FOCUS_IN_EVENT,
 171
 172   /* Generated when mouse moves over window not currently selected.  */
 173   SELECT_WINDOW_EVENT,
 174
 175   /* Queued from XTread_socket when session manager sends
 176      save yourself before shutdown. */
 177   SAVE_SESSION_EVENT
 178
 179 #ifdef HAVE_GPM
 180   , GPM_CLICK_EVENT
 181 #endif
 182
 183 #ifdef HAVE_DBUS
 184   , DBUS_EVENT
 185 #endif
 186
 187 #ifdef WINDOWSNT
 188   /* Generated when an APPCOMMAND event is received, in response to
 189      Multimedia or Internet buttons on some keyboards.
 190      Such keys are available as normal function keys on X through the
 191      Xkeyboard extension.
 192      On Windows, some of them get mapped to normal function key events,
 193      but others need to be handled by APPCOMMAND. Handling them all as
 194      APPCOMMAND events means they can be disabled
 195      (w32-pass-multimedia-buttons-to-system), important on Windows since
 196      the system never sees these keys if Emacs claims to handle them.
 197      On X, the window manager seems to grab the keys it wants
 198      first, so this is not a problem there.  */
 199   , MULTIMEDIA_KEY_EVENT
 200 #endif
 201 };
 202
 203 /* If a struct input_event has a kind which is SELECTION_REQUEST_EVENT
 204    or SELECTION_CLEAR_EVENT, then its contents are really described
 205    by `struct selection_input_event'; see xterm.h.  */
 206
 207 /* The keyboard input buffer is an array of these structures.  Each one
 208    represents some sort of input event - a keystroke, a mouse click, or
 209    a window system event.  These get turned into their lispy forms when
 210    they are removed from the event queue.  */
 211
 212 struct input_event
 213 {
 214   /* What kind of event was this?  */
 215   enum event_kind kind;
 216
 217   /* For an ASCII_KEYSTROKE_EVENT and MULTIBYTE_CHAR_KEYSTROKE_EVENT,
 218      this is the character.
 219      For a NON_ASCII_KEYSTROKE_EVENT, this is the keysym code.
 220      For a mouse event, this is the button number.  */
 221   /* In WindowsNT, for a mouse wheel event, this is the delta.  */
 222   int code;
 223   enum scroll_bar_part part;
 224
 225   int modifiers;                /* See enum below for interpretation.  */
 226
 227   Lisp_Object x, y;
 228   unsigned long timestamp;
 229
 230   /* This is padding just to put the frame_or_window field
 231      past the size of struct selection_input_event.  */
 232   int *padding[2];
 233
 234   /* This field is copied into a vector while the event is in the queue,
 235      so that garbage collections won't kill it.  */
 236   /* In a menu_bar_event, this is a cons cell whose car is the frame
 237      and whose cdr is the Lisp object that is the event's value.  */
 238   /* This field is last so that struct selection_input_event
 239      does not overlap with it.  */
 240   Lisp_Object frame_or_window;
 241
 242   /* Additional event argument.  This is used for TOOL_BAR_EVENTs and
 243      HELP_EVENTs and avoids calling Fcons during signal handling.  */
 244   Lisp_Object arg;
 245 };
 246
 247 #define EVENT_INIT(event) bzero (&(event), sizeof (struct input_event))
 248
 249 /* Bits in the modifiers member of the input_event structure.
 250    Note that reorder_modifiers assumes that the bits are in canonical
 251    order.
 252
 253    The modifiers applied to mouse clicks are rather ornate.  The
 254    window-system-specific code should store mouse clicks with
 255    up_modifier or down_modifier set.  Having an explicit down modifier
 256    simplifies some of window-system-independent code; without it, the
 257    code would have to recognize down events by checking if the event
 258    is a mouse click lacking the click and drag modifiers.
 259
 260    The window-system independent code turns all up_modifier events
 261    bits into drag_modifier, click_modifier, double_modifier, or
 262    triple_modifier events.  The click_modifier has no written
 263    representation in the names of the symbols used as event heads,
 264    but it does appear in the Qevent_symbol_components property of the
 265    event heads.  */
 266 enum {
 267   up_modifier   =   1,          /* Only used on mouse buttons - always
 268                                    turned into a click or a drag modifier
 269                                    before lisp code sees the event.  */
 270   down_modifier =   2,          /* Only used on mouse buttons.  */
 271   drag_modifier =   4,          /* This is never used in the event
 272                                    queue; it's only used internally by
 273                                    the window-system-independent code.  */
 274   click_modifier=   8,          /* See drag_modifier.  */
 275   double_modifier= 16,          /* See drag_modifier.  */
 276   triple_modifier= 32,          /* See drag_modifier.  */
 277
 278   /* The next four modifier bits are used also in keyboard events at
 279      the Lisp level.
 280
 281      It's probably not the greatest idea to use the 2^23 bit for any
 282      modifier.  It may or may not be the sign bit, depending on
 283      VALBITS, so using it to represent a modifier key means that
 284      characters thus modified have different integer equivalents
 285      depending on the architecture they're running on.  Oh, and
 286      applying XINT to a character whose 2^23 bit is set sign-extends
 287      it, so you get a bunch of bits in the mask you didn't want.
 288
 289      The CHAR_ macros are defined in lisp.h.  */
 290   alt_modifier  =  CHAR_ALT,    /* Under X, the XK_Alt_[LR] keysyms.  */
 291   super_modifier=  CHAR_SUPER,  /* Under X, the XK_Super_[LR] keysyms.  */
 292   hyper_modifier=  CHAR_HYPER,  /* Under X, the XK_Hyper_[LR] keysyms.  */
 293   shift_modifier=  CHAR_SHIFT,
 294   ctrl_modifier =  CHAR_CTL,
 295   meta_modifier =  CHAR_META    /* Under X, the XK_Meta_[LR] keysyms.  */
 296 };
 297
 298 #ifdef HAVE_GPM
 299 #include <gpm.h>
 300 extern int handle_one_term_event (struct tty_display_info *, Gpm_Event *, struct input_event *);
 301 extern void term_mouse_moveto (int, int);
 302
 303 /* The device for which we have enabled gpm support.  */
 304 extern struct tty_display_info *gpm_tty;
 305 #endif
 306
 307 #endif /* CONSP */
 308
 309 \f
 310 struct ns_display_info;
 311 struct x_display_info;
 312 struct w32_display_info;
 313
 314 /* Terminal-local parameters. */
 315 struct terminal
 316 {
 317   /* The first two fields are really the header of a vector */
 318   /* The terminal code does not refer to them.  */
 319   EMACS_UINT size;
 320   struct Lisp_Vector *vec_next;
 321
 322   /* Parameter alist of this terminal.  */
 323   Lisp_Object param_alist;
 324
 325   /* All fields before `next_terminal' should be Lisp_Object and are traced
 326      by the GC.  All fields afterwards are ignored by the GC.  */
 327
 328   /* Chain of all terminal devices. */
 329   struct terminal *next_terminal;
 330
 331   /* Unique id for this terminal device. */
 332   int id;
 333
 334   /* The number of frames that are on this terminal. */
 335   int reference_count;
 336
 337   /* The type of the terminal device. */
 338   enum output_method type;
 339
 340   /* The name of the terminal device.  Do not use this to uniquely
 341      identify a terminal; the same device may be opened multiple
 342      times. */
 343   char *name;
 344
 345 #ifdef MULTI_KBOARD
 346   /* The terminal's keyboard object. */
 347   struct kboard *kboard;
 348 #endif
 349
 350 #ifdef HAVE_WINDOW_SYSTEM
 351   /* Cache of images.  */
 352   struct image_cache *image_cache;
 353 #endif /* HAVE_WINDOW_SYSTEM */
 354
 355   /* Device-type dependent data shared amongst all frames on this terminal. */
 356   union display_info
 357   {
 358     struct tty_display_info *tty;     /* termchar.h */
 359     struct x_display_info *x;         /* xterm.h */
 360     struct w32_display_info *w32;     /* w32term.h */
 361     struct ns_display_info *ns;       /* nsterm.h */
 362   } display_info;
 363
 364 \f
 365   /* Coding-system to be used for encoding terminal output.  This
 366      structure contains information of a coding-system specified by
 367      the function `set-terminal-coding-system'.  Also see
 368      `safe_terminal_coding' in coding.h.  */
 369   struct coding_system *terminal_coding;
 370
 371   /* Coding-system of what is sent from terminal keyboard.  This
 372      structure contains information of a coding-system specified by
 373      the function `set-keyboard-coding-system'.  */
 374   struct coding_system *keyboard_coding;
 375
 376   /* Terminal characteristics. */
 377   /* XXX Are these really used on non-termcap displays? */
 378
 379   int must_write_spaces;        /* Nonzero means spaces in the text must
 380                                    actually be output; can't just skip over
 381                                    some columns to leave them blank.  */
 382   int fast_clear_end_of_line;   /* Nonzero means terminal has a `ce' string */
 383
 384   int line_ins_del_ok;          /* Terminal can insert and delete lines */
 385   int char_ins_del_ok;          /* Terminal can insert and delete chars */
 386   int scroll_region_ok;         /* Terminal supports setting the scroll
 387                                    window */
 388   int scroll_region_cost;       /* Cost of setting the scroll window,
 389                                    measured in characters. */
 390   int memory_below_frame;       /* Terminal remembers lines scrolled
 391                                    off bottom */
 392
 393 #if 0  /* These are not used anywhere. */
 394   /* EMACS_INT baud_rate; */    /* Output speed in baud */
 395   int min_padding_speed;        /* Speed below which no padding necessary. */
 396   int dont_calculate_costs;     /* Nonzero means don't bother computing
 397                                    various cost tables; we won't use them. */
 398 #endif
 399
 400 \f
 401   /* Window-based redisplay interface for this device (0 for tty
 402      devices). */
 403   struct redisplay_interface *rif;
 404
 405   /* Frame-based redisplay interface. */
 406
 407   /* Text display hooks.  */
 408
 409   void (*cursor_to_hook) P_ ((struct frame *f, int vpos, int hpos));
 410   void (*raw_cursor_to_hook) P_ ((struct frame *, int, int));
 411
 412   void (*clear_to_end_hook) P_ ((struct frame *));
 413   void (*clear_frame_hook) P_ ((struct frame *));
 414   void (*clear_end_of_line_hook) P_ ((struct frame *, int));
 415
 416   void (*ins_del_lines_hook) P_ ((struct frame *f, int, int));
 417
 418   void (*insert_glyphs_hook) P_ ((struct frame *f, struct glyph *s, int n));
 419   void (*write_glyphs_hook) P_ ((struct frame *f, struct glyph *s, int n));
 420   void (*delete_glyphs_hook) P_ ((struct frame *, int));
 421
 422   void (*ring_bell_hook) P_ ((struct frame *f));
 423
 424   void (*reset_terminal_modes_hook) P_ ((struct terminal *));
 425   void (*set_terminal_modes_hook) P_ ((struct terminal *));
 426
 427   void (*update_begin_hook) P_ ((struct frame *));
 428   void (*update_end_hook) P_ ((struct frame *));
 429   void (*set_terminal_window_hook) P_ ((struct frame *, int));
 430
 431   /* Multi-frame and mouse support hooks.  */
 432
 433   /* Return the current position of the mouse.
 434
 435      Set *f to the frame the mouse is in, or zero if the mouse is in no
 436      Emacs frame.  If it is set to zero, all the other arguments are
 437      garbage.
 438
 439      If the motion started in a scroll bar, set *bar_window to the
 440      scroll bar's window, *part to the part the mouse is currently over,
 441      *x to the position of the mouse along the scroll bar, and *y to the
 442      overall length of the scroll bar.
 443
 444      Otherwise, set *bar_window to Qnil, and *x and *y to the column and
 445      row of the character cell the mouse is over.
 446
 447      Set *time to the time the mouse was at the returned position.
 448
 449      This should clear mouse_moved until the next motion
 450      event arrives.  */
 451   void (*mouse_position_hook) P_ ((struct frame **f, int,
 452                                    Lisp_Object *bar_window,
 453                                    enum scroll_bar_part *part,
 454                                    Lisp_Object *x,
 455                                    Lisp_Object *y,
 456                                    unsigned long *time));
 457
 458   /* The window system handling code should set this if the mouse has
 459      moved since the last call to the mouse_position_hook.  Calling that
 460      hook should clear this.  */
 461   int mouse_moved;
 462
 463   /* When a frame's focus redirection is changed, this hook tells the
 464      window system code to re-decide where to put the highlight.  Under
 465      X, this means that Emacs lies about where the focus is.  */
 466   void (*frame_rehighlight_hook) P_ ((struct frame *));
 467
 468   /* If we're displaying frames using a window system that can stack
 469      frames on top of each other, this hook allows you to bring a frame
 470      to the front, or bury it behind all the other windows.  If this
 471      hook is zero, that means the terminal we're displaying on doesn't
 472      support overlapping frames, so there's no need to raise or lower
 473      anything.
 474
 475      If RAISE is non-zero, F is brought to the front, before all other
 476      windows.  If RAISE is zero, F is sent to the back, behind all other
 477      windows.  */
 478   void (*frame_raise_lower_hook) P_ ((struct frame *f, int raise));
 479
 480   /* If the value of the frame parameter changed, whis hook is called.
 481      For example, if going from fullscreen to not fullscreen this hook
 482      may do something OS dependent, like extended window manager hints on X11.  */
 483   void (*fullscreen_hook) P_ ((struct frame *f));
 484
 485   \f
 486   /* Scroll bar hooks.  */
 487
 488   /* The representation of scroll bars is determined by the code which
 489      implements them, except for one thing: they must be represented by
 490      lisp objects.  This allows us to place references to them in
 491      Lisp_Windows without worrying about those references becoming
 492      dangling references when the scroll bar is destroyed.
 493
 494      The window-system-independent portion of Emacs just refers to
 495      scroll bars via their windows, and never looks inside the scroll bar
 496      representation; it always uses hook functions to do all the
 497      scroll bar manipulation it needs.
 498
 499      The `vertical_scroll_bar' field of a Lisp_Window refers to that
 500      window's scroll bar, or is nil if the window doesn't have a
 501      scroll bar.
 502
 503      The `scroll_bars' and `condemned_scroll_bars' fields of a Lisp_Frame
 504      are free for use by the scroll bar implementation in any way it sees
 505      fit.  They are marked by the garbage collector.  */
 506
 507
 508   /* Set the vertical scroll bar for WINDOW to have its upper left corner
 509      at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 510      indicate that we are displaying PORTION characters out of a total
 511      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 512      have a scroll bar, create one for it.  */
 513   void (*set_vertical_scroll_bar_hook) P_ ((struct window *window,
 514                                             int portion, int whole,
 515                                             int position));
 516
 517
 518   /* The following three hooks are used when we're doing a thorough
 519      redisplay of the frame.  We don't explicitly know which scroll bars
 520      are going to be deleted, because keeping track of when windows go
 521      away is a real pain - can you say set-window-configuration?
 522      Instead, we just assert at the beginning of redisplay that *all*
 523      scroll bars are to be removed, and then save scroll bars from the
 524      fiery pit when we actually redisplay their window.  */
 525
 526   /* Arrange for all scroll bars on FRAME to be removed at the next call
 527      to `*judge_scroll_bars_hook'.  A scroll bar may be spared if
 528      `*redeem_scroll_bar_hook' is applied to its window before the judgement.
 529
 530      This should be applied to each frame each time its window tree is
 531      redisplayed, even if it is not displaying scroll bars at the moment;
 532      if the HAS_SCROLL_BARS flag has just been turned off, only calling
 533      this and the judge_scroll_bars_hook will get rid of them.
 534
 535      If non-zero, this hook should be safe to apply to any frame,
 536      whether or not it can support scroll bars, and whether or not it is
 537      currently displaying them.  */
 538   void (*condemn_scroll_bars_hook) P_ ((struct frame *frame));
 539
 540   /* Unmark WINDOW's scroll bar for deletion in this judgement cycle.
 541      Note that it's okay to redeem a scroll bar that is not condemned.  */
 542   void (*redeem_scroll_bar_hook) P_ ((struct window *window));
 543
 544   /* Remove all scroll bars on FRAME that haven't been saved since the
 545      last call to `*condemn_scroll_bars_hook'.
 546
 547      This should be applied to each frame after each time its window
 548      tree is redisplayed, even if it is not displaying scroll bars at the
 549      moment; if the HAS_SCROLL_BARS flag has just been turned off, only
 550      calling this and condemn_scroll_bars_hook will get rid of them.
 551
 552      If non-zero, this hook should be safe to apply to any frame,
 553      whether or not it can support scroll bars, and whether or not it is
 554      currently displaying them.  */
 555   void (*judge_scroll_bars_hook) P_ ((struct frame *FRAME));
 556
 557 \f
 558   /* Called to read input events.
 559
 560      TERMINAL indicates which terminal device to read from.  Input
 561      events should be read into BUF, the size of which is given in
 562      SIZE.  EXPECTED is non-zero if the caller suspects that new input
 563      is available.
 564
 565      A positive return value indicates that that many input events
 566      where read into BUF.
 567      Zero means no events were immediately available.
 568      A value of -1 means a transient read error, while -2 indicates
 569      that the device was closed (hangup), and it should be deleted.
 570
 571      XXX Please note that a non-zero value of EXPECTED only means that
 572      there is available input on at least one of the currently opened
 573      terminal devices -- but not necessarily on this device.
 574      Therefore, in most cases EXPECTED should be simply ignored.
 575
 576      XXX This documentation needs to be updated.  */
 577   int (*read_socket_hook) P_ ((struct terminal *terminal,
 578                                int expected,
 579                                struct input_event *hold_quit));
 580
 581   /* Called when a frame's display becomes entirely up to date.  */
 582   void (*frame_up_to_date_hook) P_ ((struct frame *));
 583
 584 \f
 585   /* Called to delete the device-specific portions of a frame that is
 586      on this terminal device. */
 587   void (*delete_frame_hook) P_ ((struct frame *));
 588
 589   /* Called after the last frame on this terminal is deleted, or when
 590      the display device was closed (hangup).
 591
 592      If this is NULL, then the generic delete_terminal is called
 593      instead.  Otherwise the hook must call delete_terminal itself.
 594
 595      The hook must check for and close any live frames that are still
 596      on the terminal.  Fdelete_frame ensures that there are no live
 597      frames on the terminal when it calls this hook, so infinite
 598      recursion is prevented.  */
 599   void (*delete_terminal_hook) P_ ((struct terminal *));
 600 };
 601
 602
 603 /* Chain of all terminal devices currently in use. */
 604 extern struct terminal *terminal_list;
 605
 606 #define FRAME_MUST_WRITE_SPACES(f) ((f)->terminal->must_write_spaces)
 607 #define FRAME_FAST_CLEAR_END_OF_LINE(f) ((f)->terminal->fast_clear_end_of_line)
 608 #define FRAME_LINE_INS_DEL_OK(f) ((f)->terminal->line_ins_del_ok)
 609 #define FRAME_CHAR_INS_DEL_OK(f) ((f)->terminal->char_ins_del_ok)
 610 #define FRAME_SCROLL_REGION_OK(f) ((f)->terminal->scroll_region_ok)
 611 #define FRAME_SCROLL_REGION_COST(f) ((f)->terminal->scroll_region_cost)
 612 #define FRAME_MEMORY_BELOW_FRAME(f) ((f)->terminal->memory_below_frame)
 613
 614 #define FRAME_TERMINAL_CODING(f) ((f)->terminal->terminal_coding)
 615 #define FRAME_KEYBOARD_CODING(f) ((f)->terminal->keyboard_coding)
 616
 617 #define TERMINAL_TERMINAL_CODING(d) ((d)->terminal_coding)
 618 #define TERMINAL_KEYBOARD_CODING(d) ((d)->keyboard_coding)
 619
 620 #define FRAME_RIF(f) ((f)->terminal->rif)
 621
 622 #define FRAME_TERMINAL(f) ((f)->terminal)
 623
 624 /* FRAME_WINDOW_P tests whether the frame is a window, and is
 625    defined to be the predicate for the window system being used.  */
 626
 627 #ifdef HAVE_X_WINDOWS
 628 #define FRAME_WINDOW_P(f) FRAME_X_P (f)
 629 #endif
 630 #ifdef HAVE_NTGUI
 631 #define FRAME_WINDOW_P(f) FRAME_W32_P (f)
 632 #endif
 633 #ifndef FRAME_WINDOW_P
 634 #define FRAME_WINDOW_P(f) (0)
 635 #endif
 636
 637 /* Return true if the terminal device is not suspended. */
 638 #define TERMINAL_ACTIVE_P(d) ((d)->type != output_termcap || (d)->display_info.tty->input)
 639
 640 extern Lisp_Object get_terminal_param P_ ((struct terminal *, Lisp_Object));
 641 extern struct terminal *get_terminal P_ ((Lisp_Object terminal, int));
 642 extern struct terminal *create_terminal P_ ((void));
 643 extern void delete_terminal P_ ((struct terminal *));
 644
 645 /* The initial terminal device, created by initial_term_init. */
 646 extern struct terminal *initial_terminal;
 647
 648 /* arch-tag: 33a00ecc-52b5-4186-a410-8801ac9f087d
 649    (do not change this comment) */