src/termhooks.h

   1 /* Parameters and display hooks for terminal devices.
   2
   3 Copyright (C) 1985-1986, 1993-1994, 2001-2012  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 #include "systime.h" /* for Time */
  24
  25 struct glyph;
  26 struct frame;
  27 \f
  28
  29 enum scroll_bar_part {
  30   scroll_bar_above_handle,
  31   scroll_bar_handle,
  32   scroll_bar_below_handle,
  33   scroll_bar_up_arrow,
  34   scroll_bar_down_arrow,
  35   scroll_bar_to_top,
  36   scroll_bar_to_bottom,
  37   scroll_bar_end_scroll,
  38   scroll_bar_move_ratio
  39 };
  40
  41 /* If the value of the frame parameter changed, whis hook is called.
  42    For example, if going from fullscreen to not fullscreen this hook
  43    may do something OS dependent, like extended window manager hints on X11.  */
  44 extern void (*fullscreen_hook) (struct frame *f);
  45
  46 \f
  47 /* Input queue declarations and hooks.  */
  48
  49 enum event_kind
  50 {
  51   NO_EVENT,                     /* nothing happened.  This should never
  52                                    actually appear in the event queue.  */
  53
  54   ASCII_KEYSTROKE_EVENT,        /* The ASCII code is in .code, perhaps
  55                                    with modifiers applied.
  56                                    .modifiers holds the state of the
  57                                    modifier keys.
  58                                    .frame_or_window is the frame in
  59                                    which the key was typed.
  60                                    .timestamp gives a timestamp (in
  61                                    milliseconds) for the keystroke.  */
  62   MULTIBYTE_CHAR_KEYSTROKE_EVENT,       /* The multibyte char code is in .code,
  63                                    perhaps with modifiers applied.
  64                                    The others are the same as
  65                                    ASCII_KEYSTROKE_EVENT.  */
  66   NON_ASCII_KEYSTROKE_EVENT,    /* .code is a number identifying the
  67                                    function key.  A code N represents
  68                                    a key whose name is
  69                                    function_key_names[N]; function_key_names
  70                                    is a table in keyboard.c to which you
  71                                    should feel free to add missing keys.
  72                                    .modifiers holds the state of the
  73                                    modifier keys.
  74                                    .frame_or_window is the frame in
  75                                    which the key was typed.
  76                                    .timestamp gives a timestamp (in
  77                                    milliseconds) for the keystroke.  */
  78   TIMER_EVENT,                  /* A timer fired.  */
  79   MOUSE_CLICK_EVENT,            /* The button number is in .code; it must
  80                                    be >= 0 and < NUM_MOUSE_BUTTONS, defined
  81                                    below.
  82                                    .modifiers holds the state of the
  83                                    modifier keys.
  84                                    .x and .y give the mouse position,
  85                                    in characters, within the window.
  86                                    .frame_or_window gives the frame
  87                                    the mouse click occurred in.
  88                                    .timestamp gives a timestamp (in
  89                                    milliseconds) for the click.  */
  90   WHEEL_EVENT,                  /* A wheel event is generated by a
  91                                    wheel on a mouse (e.g., MS
  92                                    Intellimouse).
  93                                    .modifiers holds the rotate
  94                                    direction (up or down), and the
  95                                    state of the modifier keys.
  96                                    .x and .y give the mouse position,
  97                                    in characters, within the window.
  98                                    .frame_or_window gives the frame
  99                                    the wheel event occurred in.
 100                                    .timestamp gives a timestamp (in
 101                                    milliseconds) for the event.  */
 102   HORIZ_WHEEL_EVENT,            /* A wheel event generated by a second
 103                                    horizontal wheel that is present on some
 104                                    mice. See WHEEL_EVENT.  */
 105 #if defined (WINDOWSNT)
 106   LANGUAGE_CHANGE_EVENT,        /* A LANGUAGE_CHANGE_EVENT is
 107                                    generated on WINDOWSNT or Mac OS
 108                                    when the keyboard layout or input
 109                                    language is changed by the
 110                                    user.  */
 111 #endif
 112   SCROLL_BAR_CLICK_EVENT,       /* .code gives the number of the mouse button
 113                                    that was clicked.
 114                                    .modifiers holds the state of the modifier
 115                                    keys.
 116                                    .part is a lisp symbol indicating which
 117                                    part of the scroll bar got clicked.
 118                                    .x gives the distance from the start of the
 119                                    scroll bar of the click; .y gives the total
 120                                    length of the scroll bar.
 121                                    .frame_or_window gives the window
 122                                    whose scroll bar was clicked in.
 123                                    .timestamp gives a timestamp (in
 124                                    milliseconds) for the click.  */
 125   SELECTION_REQUEST_EVENT,      /* Another X client wants a selection from us.
 126                                    See `struct selection_input_event'.  */
 127   SELECTION_CLEAR_EVENT,        /* Another X client cleared our selection.  */
 128   BUFFER_SWITCH_EVENT,          /* A process filter has switched buffers.  */
 129   DELETE_WINDOW_EVENT,          /* An X client said "delete this window".  */
 130   MENU_BAR_EVENT,               /* An event generated by the menu bar.
 131                                    The frame_or_window field's cdr holds the
 132                                    Lisp-level event value.
 133                                    (Only the toolkit version uses these.)  */
 134   ICONIFY_EVENT,                /* An X client iconified this window.  */
 135   DEICONIFY_EVENT,              /* An X client deiconified this window.  */
 136   MENU_BAR_ACTIVATE_EVENT,      /* A button press in the menu bar
 137                                    (toolkit version only).  */
 138   DRAG_N_DROP_EVENT,            /* A drag-n-drop event is generated when
 139                                    files selected outside of Emacs are dropped
 140                                    onto an Emacs window.
 141                                    .modifiers holds the state of the
 142                                    modifier keys.
 143                                    .x and .y give the mouse position,
 144                                    in characters, within the window.
 145                                    .frame_or_window is the frame in
 146                                    which the drop was made.
 147                                    .arg is a platform-dependent
 148                                    representation of the dropped items.
 149                                    .timestamp gives a timestamp (in
 150                                    milliseconds) for the click.  */
 151   USER_SIGNAL_EVENT,            /* A user signal.
 152                                    code is a number identifying it,
 153                                    index into lispy_user_signals.  */
 154
 155   /* Help events.  Member `frame_or_window' of the input_event is the
 156      frame on which the event occurred, and member `arg' contains
 157      the help to show.  */
 158   HELP_EVENT,
 159
 160   /* An event from a tool-bar.  Member `arg' of the input event
 161      contains the tool-bar item selected.  If `frame_or_window'
 162      and `arg' are equal, this is a prefix event.  */
 163   TOOL_BAR_EVENT,
 164
 165   /* Queued from XTread_socket on FocusIn events.  Translated into
 166      `switch-frame' events in kbd_buffer_get_event, if necessary.  */
 167   FOCUS_IN_EVENT,
 168
 169   /* Generated when mouse moves over window not currently selected.  */
 170   SELECT_WINDOW_EVENT,
 171
 172   /* Queued from XTread_socket when session manager sends
 173      save yourself before shutdown. */
 174   SAVE_SESSION_EVENT
 175
 176 #ifdef HAVE_GPM
 177   , GPM_CLICK_EVENT
 178 #endif
 179
 180 #ifdef HAVE_DBUS
 181   , DBUS_EVENT
 182 #endif
 183
 184   , CONFIG_CHANGED_EVENT
 185
 186 #ifdef WINDOWSNT
 187   /* Generated when an APPCOMMAND event is received, in response to
 188      Multimedia or Internet buttons on some keyboards.
 189      Such keys are available as normal function keys on X through the
 190      Xkeyboard extension.
 191      On Windows, some of them get mapped to normal function key events,
 192      but others need to be handled by APPCOMMAND. Handling them all as
 193      APPCOMMAND events means they can be disabled
 194      (w32-pass-multimedia-buttons-to-system), important on Windows since
 195      the system never sees these keys if Emacs claims to handle them.
 196      On X, the window manager seems to grab the keys it wants
 197      first, so this is not a problem there.  */
 198   , MULTIMEDIA_KEY_EVENT
 199 #endif
 200
 201 #ifdef HAVE_NS
 202   /* Generated when native multi-keystroke input method is used to modify
 203      tentative or indicative text display. */
 204   , NS_TEXT_EVENT
 205   /* Non-key system events (e.g. application menu events) */
 206   , NS_NONKEY_EVENT
 207 #endif
 208
 209 };
 210
 211 /* If a struct input_event has a kind which is SELECTION_REQUEST_EVENT
 212    or SELECTION_CLEAR_EVENT, then its contents are really described
 213    by `struct selection_input_event'; see xterm.h.  */
 214
 215 /* The keyboard input buffer is an array of these structures.  Each one
 216    represents some sort of input event - a keystroke, a mouse click, or
 217    a window system event.  These get turned into their lispy forms when
 218    they are removed from the event queue.  */
 219
 220 struct input_event
 221 {
 222   /* What kind of event was this?  */
 223   enum event_kind kind;
 224
 225   /* For an ASCII_KEYSTROKE_EVENT and MULTIBYTE_CHAR_KEYSTROKE_EVENT,
 226      this is the character.
 227      For a NON_ASCII_KEYSTROKE_EVENT, this is the keysym code.
 228      For a mouse event, this is the button number.
 229      For a HELP_EVENT, this is the position within the object
 230       (stored in ARG below) where the help was found.  */
 231   /* In WindowsNT, for a mouse wheel event, this is the delta.  */
 232   ptrdiff_t code;
 233   enum scroll_bar_part part;
 234
 235   int modifiers;                /* See enum below for interpretation.  */
 236
 237   Lisp_Object x, y;
 238   Time timestamp;
 239
 240   /* This is padding just to put the frame_or_window field
 241      past the size of struct selection_input_event.  */
 242   int *padding[2];
 243
 244   /* This field is copied into a vector while the event is in the queue,
 245      so that garbage collections won't kill it.  */
 246   /* In a menu_bar_event, this is a cons cell whose car is the frame
 247      and whose cdr is the Lisp object that is the event's value.  */
 248   /* This field is last so that struct selection_input_event
 249      does not overlap with it.  */
 250   Lisp_Object frame_or_window;
 251
 252   /* Additional event argument.  This is used for TOOL_BAR_EVENTs and
 253      HELP_EVENTs and avoids calling Fcons during signal handling.  */
 254   Lisp_Object arg;
 255 };
 256
 257 #define EVENT_INIT(event) memset (&(event), 0, sizeof (struct input_event))
 258
 259 /* Bits in the modifiers member of the input_event structure.
 260    Note that reorder_modifiers assumes that the bits are in canonical
 261    order.
 262
 263    The modifiers applied to mouse clicks are rather ornate.  The
 264    window-system-specific code should store mouse clicks with
 265    up_modifier or down_modifier set.  Having an explicit down modifier
 266    simplifies some of window-system-independent code; without it, the
 267    code would have to recognize down events by checking if the event
 268    is a mouse click lacking the click and drag modifiers.
 269
 270    The window-system independent code turns all up_modifier events
 271    bits into drag_modifier, click_modifier, double_modifier, or
 272    triple_modifier events.  The click_modifier has no written
 273    representation in the names of the symbols used as event heads,
 274    but it does appear in the Qevent_symbol_components property of the
 275    event heads.  */
 276 enum {
 277   up_modifier   =   1,          /* Only used on mouse buttons - always
 278                                    turned into a click or a drag modifier
 279                                    before lisp code sees the event.  */
 280   down_modifier =   2,          /* Only used on mouse buttons.  */
 281   drag_modifier =   4,          /* This is never used in the event
 282                                    queue; it's only used internally by
 283                                    the window-system-independent code.  */
 284   click_modifier=   8,          /* See drag_modifier.  */
 285   double_modifier= 16,          /* See drag_modifier.  */
 286   triple_modifier= 32,          /* See drag_modifier.  */
 287
 288   /* The next four modifier bits are used also in keyboard events at
 289      the Lisp level.
 290
 291      It's probably not the greatest idea to use the 2^28 bit for any
 292      modifier.  It may or may not be the sign bit, depending on
 293      FIXNUM_BITS, so using it to represent a modifier key means that
 294      characters thus modified have different integer equivalents
 295      depending on the architecture they're running on.  Oh, and
 296      applying XINT to a character whose 2^28 bit is set might sign-extend
 297      it, so you get a bunch of bits in the mask you didn't want.
 298
 299      The CHAR_ macros are defined in lisp.h.  */
 300   alt_modifier  =  CHAR_ALT,    /* Under X, the XK_Alt_[LR] keysyms.  */
 301   super_modifier=  CHAR_SUPER,  /* Under X, the XK_Super_[LR] keysyms.  */
 302   hyper_modifier=  CHAR_HYPER,  /* Under X, the XK_Hyper_[LR] keysyms.  */
 303   shift_modifier=  CHAR_SHIFT,
 304   ctrl_modifier =  CHAR_CTL,
 305   meta_modifier =  CHAR_META    /* Under X, the XK_Meta_[LR] keysyms.  */
 306 };
 307
 308 #ifdef HAVE_GPM
 309 #include <gpm.h>
 310 extern int handle_one_term_event (struct tty_display_info *, Gpm_Event *, struct input_event *);
 311 #ifndef HAVE_WINDOW_SYSTEM
 312 extern void term_mouse_moveto (int, int);
 313 #endif
 314
 315 /* The device for which we have enabled gpm support.  */
 316 extern struct tty_display_info *gpm_tty;
 317 #endif
 318
 319 \f
 320 struct ns_display_info;
 321 struct x_display_info;
 322 struct w32_display_info;
 323
 324 /* Terminal-local parameters. */
 325 struct terminal
 326 {
 327   /* This is for Lisp; the terminal code does not refer to it.  */
 328   struct vectorlike_header header;
 329
 330   /* Parameter alist of this terminal.  */
 331   Lisp_Object param_alist;
 332
 333   /* List of charsets supported by the terminal.  It is set by
 334      Fset_terminal_coding_system_internal along with
 335      the member terminal_coding.  */
 336   Lisp_Object charset_list;
 337
 338   /* This is an association list containing the X selections that
 339      Emacs might own on this terminal.  Each element has the form
 340        (SELECTION-NAME SELECTION-VALUE SELECTION-TIMESTAMP FRAME)
 341      SELECTION-NAME is a lisp symbol, whose name is the name of an X Atom.
 342      SELECTION-VALUE is the value that emacs owns for that selection.
 343       It may be any kind of Lisp object.
 344      SELECTION-TIMESTAMP is the time at which emacs began owning this
 345       selection, as a cons of two 16-bit numbers (making a 32 bit
 346       time.)
 347      FRAME is the frame for which we made the selection.  If there is
 348       an entry in this alist, then it can be assumed that Emacs owns
 349       that selection.
 350      The only (eq) parts of this list that are visible from Lisp are
 351     the selection-values.  */
 352   Lisp_Object Vselection_alist;
 353
 354   /* All fields before `next_terminal' should be Lisp_Object and are traced
 355      by the GC.  All fields afterwards are ignored by the GC.  */
 356
 357   /* Chain of all terminal devices. */
 358   struct terminal *next_terminal;
 359
 360   /* Unique id for this terminal device. */
 361   int id;
 362
 363   /* The number of frames that are on this terminal. */
 364   int reference_count;
 365
 366   /* The type of the terminal device. */
 367   enum output_method type;
 368
 369   /* The name of the terminal device.  Do not use this to uniquely
 370      identify a terminal; the same device may be opened multiple
 371      times. */
 372   char *name;
 373
 374   /* The terminal's keyboard object. */
 375   struct kboard *kboard;
 376
 377 #ifdef HAVE_WINDOW_SYSTEM
 378   /* Cache of images.  */
 379   struct image_cache *image_cache;
 380 #endif /* HAVE_WINDOW_SYSTEM */
 381
 382   /* Device-type dependent data shared amongst all frames on this terminal. */
 383   union display_info
 384   {
 385     struct tty_display_info *tty;     /* termchar.h */
 386     struct x_display_info *x;         /* xterm.h */
 387     struct w32_display_info *w32;     /* w32term.h */
 388     struct ns_display_info *ns;       /* nsterm.h */
 389   } display_info;
 390
 391 \f
 392   /* Coding-system to be used for encoding terminal output.  This
 393      structure contains information of a coding-system specified by
 394      the function `set-terminal-coding-system'.  Also see
 395      `safe_terminal_coding' in coding.h.  */
 396   struct coding_system *terminal_coding;
 397
 398   /* Coding-system of what is sent from terminal keyboard.  This
 399      structure contains information of a coding-system specified by
 400      the function `set-keyboard-coding-system'.  */
 401   struct coding_system *keyboard_coding;
 402
 403   /* Terminal characteristics. */
 404   /* XXX Are these really used on non-termcap displays? */
 405
 406   int must_write_spaces;        /* Nonzero means spaces in the text must
 407                                    actually be output; can't just skip over
 408                                    some columns to leave them blank.  */
 409   int fast_clear_end_of_line;   /* Nonzero means terminal has a `ce' string */
 410
 411   int line_ins_del_ok;          /* Terminal can insert and delete lines */
 412   int char_ins_del_ok;          /* Terminal can insert and delete chars */
 413   int scroll_region_ok;         /* Terminal supports setting the scroll
 414                                    window */
 415   int scroll_region_cost;       /* Cost of setting the scroll window,
 416                                    measured in characters. */
 417   int memory_below_frame;       /* Terminal remembers lines scrolled
 418                                    off bottom */
 419
 420 #if 0  /* These are not used anywhere. */
 421   /* EMACS_INT baud_rate; */    /* Output speed in baud */
 422   int min_padding_speed;        /* Speed below which no padding necessary. */
 423   int dont_calculate_costs;     /* Nonzero means don't bother computing
 424                                    various cost tables; we won't use them. */
 425 #endif
 426
 427 \f
 428   /* Window-based redisplay interface for this device (0 for tty
 429      devices). */
 430   struct redisplay_interface *rif;
 431
 432   /* Frame-based redisplay interface. */
 433
 434   /* Text display hooks.  */
 435
 436   void (*cursor_to_hook) (struct frame *f, int vpos, int hpos);
 437   void (*raw_cursor_to_hook) (struct frame *, int, int);
 438
 439   void (*clear_to_end_hook) (struct frame *);
 440   void (*clear_frame_hook) (struct frame *);
 441   void (*clear_end_of_line_hook) (struct frame *, int);
 442
 443   void (*ins_del_lines_hook) (struct frame *f, int, int);
 444
 445   void (*insert_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 446   void (*write_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 447   void (*delete_glyphs_hook) (struct frame *, int);
 448
 449   void (*ring_bell_hook) (struct frame *f);
 450   void (*toggle_invisible_pointer_hook) (struct frame *f, int invisible);
 451
 452   void (*reset_terminal_modes_hook) (struct terminal *);
 453   void (*set_terminal_modes_hook) (struct terminal *);
 454
 455   void (*update_begin_hook) (struct frame *);
 456   void (*update_end_hook) (struct frame *);
 457   void (*set_terminal_window_hook) (struct frame *, int);
 458
 459   /* Multi-frame and mouse support hooks.  */
 460
 461   /* Return the current position of the mouse.
 462
 463      Set *f to the frame the mouse is in, or zero if the mouse is in no
 464      Emacs frame.  If it is set to zero, all the other arguments are
 465      garbage.
 466
 467      If the motion started in a scroll bar, set *bar_window to the
 468      scroll bar's window, *part to the part the mouse is currently over,
 469      *x to the position of the mouse along the scroll bar, and *y to the
 470      overall length of the scroll bar.
 471
 472      Otherwise, set *bar_window to Qnil, and *x and *y to the column and
 473      row of the character cell the mouse is over.
 474
 475      Set *time to the time the mouse was at the returned position.
 476
 477      This should clear mouse_moved until the next motion
 478      event arrives.  */
 479   void (*mouse_position_hook) (struct frame **f, int,
 480                                Lisp_Object *bar_window,
 481                                enum scroll_bar_part *part,
 482                                Lisp_Object *x,
 483                                Lisp_Object *y,
 484                                Time *);
 485
 486   /* The window system handling code should set this if the mouse has
 487      moved since the last call to the mouse_position_hook.  Calling that
 488      hook should clear this.  */
 489   int mouse_moved;
 490
 491   /* When a frame's focus redirection is changed, this hook tells the
 492      window system code to re-decide where to put the highlight.  Under
 493      X, this means that Emacs lies about where the focus is.  */
 494   void (*frame_rehighlight_hook) (struct frame *);
 495
 496   /* If we're displaying frames using a window system that can stack
 497      frames on top of each other, this hook allows you to bring a frame
 498      to the front, or bury it behind all the other windows.  If this
 499      hook is zero, that means the terminal we're displaying on doesn't
 500      support overlapping frames, so there's no need to raise or lower
 501      anything.
 502
 503      If RAISE_FLAG is non-zero, F is brought to the front, before all other
 504      windows.  If RAISE_FLAG is zero, F is sent to the back, behind all other
 505      windows.  */
 506   void (*frame_raise_lower_hook) (struct frame *f, int raise_flag);
 507
 508   /* If the value of the frame parameter changed, whis hook is called.
 509      For example, if going from fullscreen to not fullscreen this hook
 510      may do something OS dependent, like extended window manager hints on X11.  */
 511   void (*fullscreen_hook) (struct frame *f);
 512
 513   \f
 514   /* Scroll bar hooks.  */
 515
 516   /* The representation of scroll bars is determined by the code which
 517      implements them, except for one thing: they must be represented by
 518      lisp objects.  This allows us to place references to them in
 519      Lisp_Windows without worrying about those references becoming
 520      dangling references when the scroll bar is destroyed.
 521
 522      The window-system-independent portion of Emacs just refers to
 523      scroll bars via their windows, and never looks inside the scroll bar
 524      representation; it always uses hook functions to do all the
 525      scroll bar manipulation it needs.
 526
 527      The `vertical_scroll_bar' field of a Lisp_Window refers to that
 528      window's scroll bar, or is nil if the window doesn't have a
 529      scroll bar.
 530
 531      The `scroll_bars' and `condemned_scroll_bars' fields of a Lisp_Frame
 532      are free for use by the scroll bar implementation in any way it sees
 533      fit.  They are marked by the garbage collector.  */
 534
 535
 536   /* Set the vertical scroll bar for WINDOW to have its upper left corner
 537      at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 538      indicate that we are displaying PORTION characters out of a total
 539      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 540      have a scroll bar, create one for it.  */
 541   void (*set_vertical_scroll_bar_hook) (struct window *window,
 542                                         int portion, int whole,
 543                                         int position);
 544
 545
 546   /* The following three hooks are used when we're doing a thorough
 547      redisplay of the frame.  We don't explicitly know which scroll bars
 548      are going to be deleted, because keeping track of when windows go
 549      away is a real pain - can you say set-window-configuration?
 550      Instead, we just assert at the beginning of redisplay that *all*
 551      scroll bars are to be removed, and then save scroll bars from the
 552      fiery pit when we actually redisplay their window.  */
 553
 554   /* Arrange for all scroll bars on FRAME to be removed at the next call
 555      to `*judge_scroll_bars_hook'.  A scroll bar may be spared if
 556      `*redeem_scroll_bar_hook' is applied to its window before the judgment.
 557
 558      This should be applied to each frame each time its window tree is
 559      redisplayed, even if it is not displaying scroll bars at the moment;
 560      if the HAS_SCROLL_BARS flag has just been turned off, only calling
 561      this and the judge_scroll_bars_hook will get rid of them.
 562
 563      If non-zero, this hook should be safe to apply to any frame,
 564      whether or not it can support scroll bars, and whether or not it is
 565      currently displaying them.  */
 566   void (*condemn_scroll_bars_hook) (struct frame *frame);
 567
 568   /* Unmark WINDOW's scroll bar for deletion in this judgment cycle.
 569      Note that it's okay to redeem a scroll bar that is not condemned.  */
 570   void (*redeem_scroll_bar_hook) (struct window *window);
 571
 572   /* Remove all scroll bars on FRAME that haven't been saved since the
 573      last call to `*condemn_scroll_bars_hook'.
 574
 575      This should be applied to each frame after each time its window
 576      tree is redisplayed, even if it is not displaying scroll bars at the
 577      moment; if the HAS_SCROLL_BARS flag has just been turned off, only
 578      calling this and condemn_scroll_bars_hook will get rid of them.
 579
 580      If non-zero, this hook should be safe to apply to any frame,
 581      whether or not it can support scroll bars, and whether or not it is
 582      currently displaying them.  */
 583   void (*judge_scroll_bars_hook) (struct frame *FRAME);
 584
 585 \f
 586   /* Called to read input events.
 587
 588      TERMINAL indicates which terminal device to read from.  Input
 589      events should be read into BUF, the size of which is given in
 590      SIZE.  EXPECTED is non-zero if the caller suspects that new input
 591      is available.
 592
 593      A positive return value indicates that that many input events
 594      where read into BUF.
 595      Zero means no events were immediately available.
 596      A value of -1 means a transient read error, while -2 indicates
 597      that the device was closed (hangup), and it should be deleted.
 598
 599      XXX Please note that a non-zero value of EXPECTED only means that
 600      there is available input on at least one of the currently opened
 601      terminal devices -- but not necessarily on this device.
 602      Therefore, in most cases EXPECTED should be simply ignored.
 603
 604      XXX This documentation needs to be updated.  */
 605   int (*read_socket_hook) (struct terminal *terminal,
 606                            int expected,
 607                            struct input_event *hold_quit);
 608
 609   /* Called when a frame's display becomes entirely up to date.  */
 610   void (*frame_up_to_date_hook) (struct frame *);
 611
 612 \f
 613   /* Called to delete the device-specific portions of a frame that is
 614      on this terminal device. */
 615   void (*delete_frame_hook) (struct frame *);
 616
 617   /* Called after the last frame on this terminal is deleted, or when
 618      the display device was closed (hangup).
 619
 620      If this is NULL, then the generic delete_terminal is called
 621      instead.  Otherwise the hook must call delete_terminal itself.
 622
 623      The hook must check for and close any live frames that are still
 624      on the terminal.  delete_frame ensures that there are no live
 625      frames on the terminal when it calls this hook, so infinite
 626      recursion is prevented.  */
 627   void (*delete_terminal_hook) (struct terminal *);
 628 };
 629
 630
 631 /* Chain of all terminal devices currently in use. */
 632 extern struct terminal *terminal_list;
 633
 634 #define FRAME_MUST_WRITE_SPACES(f) ((f)->terminal->must_write_spaces)
 635 #define FRAME_FAST_CLEAR_END_OF_LINE(f) ((f)->terminal->fast_clear_end_of_line)
 636 #define FRAME_LINE_INS_DEL_OK(f) ((f)->terminal->line_ins_del_ok)
 637 #define FRAME_CHAR_INS_DEL_OK(f) ((f)->terminal->char_ins_del_ok)
 638 #define FRAME_SCROLL_REGION_OK(f) ((f)->terminal->scroll_region_ok)
 639 #define FRAME_SCROLL_REGION_COST(f) ((f)->terminal->scroll_region_cost)
 640 #define FRAME_MEMORY_BELOW_FRAME(f) ((f)->terminal->memory_below_frame)
 641
 642 #define FRAME_TERMINAL_CODING(f) ((f)->terminal->terminal_coding)
 643 #define FRAME_KEYBOARD_CODING(f) ((f)->terminal->keyboard_coding)
 644
 645 #define TERMINAL_TERMINAL_CODING(d) ((d)->terminal_coding)
 646 #define TERMINAL_KEYBOARD_CODING(d) ((d)->keyboard_coding)
 647
 648 #define FRAME_RIF(f) ((f)->terminal->rif)
 649
 650 #define FRAME_TERMINAL(f) ((f)->terminal)
 651
 652 /* Return true if the terminal device is not suspended. */
 653 #define TERMINAL_ACTIVE_P(d) (((d)->type != output_termcap && (d)->type !=output_msdos_raw) || (d)->display_info.tty->input)
 654
 655 extern struct terminal *get_terminal (Lisp_Object terminal, int);
 656 extern struct terminal *create_terminal (void);
 657 extern void delete_terminal (struct terminal *);
 658
 659 /* The initial terminal device, created by initial_term_init. */
 660 extern struct terminal *initial_terminal;
 661
 662 extern unsigned char *encode_terminal_code (struct glyph *, int,
 663                                             struct coding_system *);
 664
 665 #ifdef HAVE_GPM
 666 extern void close_gpm (int gpm_fd);
 667 #endif