src/termhooks.h

   1 /* Parameters and display hooks for terminal devices.
   2
   3 Copyright (C) 1985-1986, 1993-1994, 2001-2013 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
  11 (at 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 \f
  22 /* Miscellanea.   */
  23
  24 #include "systime.h" /* for Time */
  25
  26 INLINE_HEADER_BEGIN
  27 #ifndef TERMHOOKS_INLINE
  28 # define TERMHOOKS_INLINE INLINE
  29 #endif
  30
  31 struct glyph;
  32 struct frame;
  33 \f
  34
  35 enum scroll_bar_part {
  36   scroll_bar_above_handle,
  37   scroll_bar_handle,
  38   scroll_bar_below_handle,
  39   scroll_bar_up_arrow,
  40   scroll_bar_down_arrow,
  41   scroll_bar_to_top,
  42   scroll_bar_to_bottom,
  43   scroll_bar_end_scroll,
  44   scroll_bar_move_ratio
  45 };
  46
  47 /* If the value of the frame parameter changed, whis hook is called.
  48    For example, if going from fullscreen to not fullscreen this hook
  49    may do something OS dependent, like extended window manager hints on X11.  */
  50 extern void (*fullscreen_hook) (struct frame *f);
  51
  52 \f
  53 /* Input queue declarations and hooks.  */
  54
  55 enum event_kind
  56 {
  57   NO_EVENT,                     /* nothing happened.  This should never
  58                                    actually appear in the event queue.  */
  59
  60   ASCII_KEYSTROKE_EVENT,        /* The ASCII code is in .code, perhaps
  61                                    with modifiers applied.
  62                                    .modifiers holds the state of the
  63                                    modifier keys.
  64                                    .frame_or_window is the frame in
  65                                    which the key was typed.
  66                                    .timestamp gives a timestamp (in
  67                                    milliseconds) for the keystroke.  */
  68   MULTIBYTE_CHAR_KEYSTROKE_EVENT,       /* The multibyte char code is in .code,
  69                                    perhaps with modifiers applied.
  70                                    The others are the same as
  71                                    ASCII_KEYSTROKE_EVENT.  */
  72   NON_ASCII_KEYSTROKE_EVENT,    /* .code is a number identifying the
  73                                    function key.  A code N represents
  74                                    a key whose name is
  75                                    function_key_names[N]; function_key_names
  76                                    is a table in keyboard.c to which you
  77                                    should feel free to add missing keys.
  78                                    .modifiers holds the state of the
  79                                    modifier keys.
  80                                    .frame_or_window is the frame in
  81                                    which the key was typed.
  82                                    .timestamp gives a timestamp (in
  83                                    milliseconds) for the keystroke.  */
  84   TIMER_EVENT,                  /* A timer fired.  */
  85   MOUSE_CLICK_EVENT,            /* The button number is in .code; it must
  86                                    be >= 0 and < NUM_MOUSE_BUTTONS, defined
  87                                    below.
  88                                    .modifiers holds the state of the
  89                                    modifier keys.
  90                                    .x and .y give the mouse position,
  91                                    in characters, within the window.
  92                                    .frame_or_window gives the frame
  93                                    the mouse click occurred in.
  94                                    .timestamp gives a timestamp (in
  95                                    milliseconds) for the click.  */
  96   WHEEL_EVENT,                  /* A wheel event is generated by a
  97                                    wheel on a mouse (e.g., MS
  98                                    Intellimouse).
  99                                    .modifiers holds the rotate
 100                                    direction (up or down), and the
 101                                    state of the 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 wheel event occurred in.
 106                                    .timestamp gives a timestamp (in
 107                                    milliseconds) for the event.  */
 108   HORIZ_WHEEL_EVENT,            /* A wheel event generated by a second
 109                                    horizontal wheel that is present on some
 110                                    mice. See WHEEL_EVENT.  */
 111 #ifdef HAVE_NTGUI
 112   LANGUAGE_CHANGE_EVENT,        /* A LANGUAGE_CHANGE_EVENT is
 113                                    generated when HAVE_NTGUI or on Mac OS
 114                                    when the keyboard layout or input
 115                                    language is changed by the
 116                                    user.  */
 117 #endif
 118   SCROLL_BAR_CLICK_EVENT,       /* .code gives the number of the mouse button
 119                                    that was clicked.
 120                                    .modifiers holds the state of the modifier
 121                                    keys.
 122                                    .part is a lisp symbol indicating which
 123                                    part of the scroll bar got clicked.
 124                                    .x gives the distance from the start of the
 125                                    scroll bar of the click; .y gives the total
 126                                    length of the scroll bar.
 127                                    .frame_or_window gives the window
 128                                    whose scroll bar was clicked in.
 129                                    .timestamp gives a timestamp (in
 130                                    milliseconds) for the click.  */
 131   SELECTION_REQUEST_EVENT,      /* Another X client wants a selection from us.
 132                                    See `struct selection_input_event'.  */
 133   SELECTION_CLEAR_EVENT,        /* Another X client cleared our selection.  */
 134   BUFFER_SWITCH_EVENT,          /* A process filter has switched buffers.  */
 135   DELETE_WINDOW_EVENT,          /* An X client said "delete this window".  */
 136   MENU_BAR_EVENT,               /* An event generated by the menu bar.
 137                                    The frame_or_window field's cdr holds the
 138                                    Lisp-level event value.
 139                                    (Only the toolkit version uses these.)  */
 140   ICONIFY_EVENT,                /* An X client iconified this window.  */
 141   DEICONIFY_EVENT,              /* An X client deiconified this window.  */
 142   MENU_BAR_ACTIVATE_EVENT,      /* A button press in the menu bar
 143                                    (toolkit version only).  */
 144   DRAG_N_DROP_EVENT,            /* A drag-n-drop event is generated when
 145                                    files selected outside of Emacs are dropped
 146                                    onto an Emacs window.
 147                                    .modifiers holds the state of the
 148                                    modifier keys.
 149                                    .x and .y give the mouse position,
 150                                    in characters, within the window.
 151                                    .frame_or_window is the frame in
 152                                    which the drop was made.
 153                                    .arg is a platform-dependent
 154                                    representation of the dropped items.
 155                                    .timestamp gives a timestamp (in
 156                                    milliseconds) for the click.  */
 157   USER_SIGNAL_EVENT,            /* A user signal.
 158                                    code is a number identifying it,
 159                                    index into lispy_user_signals.  */
 160
 161   /* Help events.  Member `frame_or_window' of the input_event is the
 162      frame on which the event occurred, and member `arg' contains
 163      the help to show.  */
 164   HELP_EVENT,
 165
 166   /* An event from a tool-bar.  Member `arg' of the input event
 167      contains the tool-bar item selected.  If `frame_or_window'
 168      and `arg' are equal, this is a prefix event.  */
 169   TOOL_BAR_EVENT,
 170
 171   /* Queued from XTread_socket on FocusIn events.  Translated into
 172      `switch-frame' events in kbd_buffer_get_event, if necessary.  */
 173   FOCUS_IN_EVENT,
 174
 175   FOCUS_OUT_EVENT,
 176
 177   /* Generated when mouse moves over window not currently selected.  */
 178   SELECT_WINDOW_EVENT,
 179
 180   /* Queued from XTread_socket when session manager sends
 181      save yourself before shutdown. */
 182   SAVE_SESSION_EVENT
 183
 184 #ifdef HAVE_GPM
 185   , GPM_CLICK_EVENT
 186 #endif
 187
 188 #ifdef HAVE_DBUS
 189   , DBUS_EVENT
 190 #endif
 191
 192   , CONFIG_CHANGED_EVENT
 193
 194 #ifdef HAVE_NTGUI
 195   /* Generated when an APPCOMMAND event is received, in response to
 196      Multimedia or Internet buttons on some keyboards.
 197      Such keys are available as normal function keys on X through the
 198      Xkeyboard extension.
 199      On Windows, some of them get mapped to normal function key events,
 200      but others need to be handled by APPCOMMAND. Handling them all as
 201      APPCOMMAND events means they can be disabled
 202      (w32-pass-multimedia-buttons-to-system), important on Windows since
 203      the system never sees these keys if Emacs claims to handle them.
 204      On X, the window manager seems to grab the keys it wants
 205      first, so this is not a problem there.  */
 206   , MULTIMEDIA_KEY_EVENT
 207 #endif
 208
 209 #ifdef HAVE_NS
 210   /* Generated when native multi-keystroke input method is used to modify
 211      tentative or indicative text display. */
 212   , NS_TEXT_EVENT
 213   /* Non-key system events (e.g. application menu events) */
 214   , NS_NONKEY_EVENT
 215 #endif
 216
 217 #ifdef USE_FILE_NOTIFY
 218   /* File or directory was changed.  */
 219   , FILE_NOTIFY_EVENT
 220 #endif
 221
 222 };
 223
 224 /* If a struct input_event has a kind which is SELECTION_REQUEST_EVENT
 225    or SELECTION_CLEAR_EVENT, then its contents are really described
 226    by `struct selection_input_event'; see xterm.h.  */
 227
 228 /* The keyboard input buffer is an array of these structures.  Each one
 229    represents some sort of input event - a keystroke, a mouse click, or
 230    a window system event.  These get turned into their lispy forms when
 231    they are removed from the event queue.  */
 232
 233 struct input_event
 234 {
 235   /* What kind of event was this?  */
 236   enum event_kind kind;
 237
 238   /* For an ASCII_KEYSTROKE_EVENT and MULTIBYTE_CHAR_KEYSTROKE_EVENT,
 239      this is the character.
 240      For a NON_ASCII_KEYSTROKE_EVENT, this is the keysym code.
 241      For a mouse event, this is the button number.
 242      For a HELP_EVENT, this is the position within the object
 243       (stored in ARG below) where the help was found.  */
 244   /* In WindowsNT, for a mouse wheel event, this is the delta.  */
 245   ptrdiff_t code;
 246   enum scroll_bar_part part;
 247
 248   int modifiers;                /* See enum below for interpretation.  */
 249
 250   Lisp_Object x, y;
 251   Time timestamp;
 252
 253   /* This field is copied into a vector while the event is in
 254      the queue, so that garbage collections won't kill it.  */
 255   Lisp_Object frame_or_window;
 256
 257   /* Additional event argument.  This is used for TOOL_BAR_EVENTs and
 258      HELP_EVENTs and avoids calling Fcons during signal handling.  */
 259   Lisp_Object arg;
 260 };
 261
 262 #define EVENT_INIT(event) memset (&(event), 0, sizeof (struct input_event))
 263
 264 /* Bits in the modifiers member of the input_event structure.
 265    Note that reorder_modifiers assumes that the bits are in canonical
 266    order.
 267
 268    The modifiers applied to mouse clicks are rather ornate.  The
 269    window-system-specific code should store mouse clicks with
 270    up_modifier or down_modifier set.  Having an explicit down modifier
 271    simplifies some of window-system-independent code; without it, the
 272    code would have to recognize down events by checking if the event
 273    is a mouse click lacking the click and drag modifiers.
 274
 275    The window-system independent code turns all up_modifier events
 276    bits into drag_modifier, click_modifier, double_modifier, or
 277    triple_modifier events.  The click_modifier has no written
 278    representation in the names of the symbols used as event heads,
 279    but it does appear in the Qevent_symbol_components property of the
 280    event heads.  */
 281 enum {
 282   up_modifier   =   1,          /* Only used on mouse buttons - always
 283                                    turned into a click or a drag modifier
 284                                    before lisp code sees the event.  */
 285   down_modifier =   2,          /* Only used on mouse buttons.  */
 286   drag_modifier =   4,          /* This is never used in the event
 287                                    queue; it's only used internally by
 288                                    the window-system-independent code.  */
 289   click_modifier=   8,          /* See drag_modifier.  */
 290   double_modifier= 16,          /* See drag_modifier.  */
 291   triple_modifier= 32,          /* See drag_modifier.  */
 292
 293   /* The next four modifier bits are used also in keyboard events at
 294      the Lisp level.
 295
 296      It's probably not the greatest idea to use the 2^28 bit for any
 297      modifier.  It may or may not be the sign bit, depending on
 298      FIXNUM_BITS, so using it to represent a modifier key means that
 299      characters thus modified have different integer equivalents
 300      depending on the architecture they're running on.  Oh, and
 301      applying XINT to a character whose 2^28 bit is set might sign-extend
 302      it, so you get a bunch of bits in the mask you didn't want.
 303
 304      The CHAR_ macros are defined in lisp.h.  */
 305   alt_modifier  =  CHAR_ALT,    /* Under X, the XK_Alt_[LR] keysyms.  */
 306   super_modifier=  CHAR_SUPER,  /* Under X, the XK_Super_[LR] keysyms.  */
 307   hyper_modifier=  CHAR_HYPER,  /* Under X, the XK_Hyper_[LR] keysyms.  */
 308   shift_modifier=  CHAR_SHIFT,
 309   ctrl_modifier =  CHAR_CTL,
 310   meta_modifier =  CHAR_META    /* Under X, the XK_Meta_[LR] keysyms.  */
 311 };
 312
 313 #ifdef HAVE_GPM
 314 #include <gpm.h>
 315 extern int handle_one_term_event (struct tty_display_info *, Gpm_Event *, struct input_event *);
 316 #ifndef HAVE_WINDOW_SYSTEM
 317 extern void term_mouse_moveto (int, int);
 318 #endif
 319
 320 /* The device for which we have enabled gpm support.  */
 321 extern struct tty_display_info *gpm_tty;
 322 #endif
 323
 324 \f
 325 struct ns_display_info;
 326 struct x_display_info;
 327 struct w32_display_info;
 328
 329 /* Terminal-local parameters. */
 330 struct terminal
 331 {
 332   /* This is for Lisp; the terminal code does not refer to it.  */
 333   struct vectorlike_header header;
 334
 335   /* Parameter alist of this terminal.  */
 336   Lisp_Object param_alist;
 337
 338   /* List of charsets supported by the terminal.  It is set by
 339      Fset_terminal_coding_system_internal along with
 340      the member terminal_coding.  */
 341   Lisp_Object charset_list;
 342
 343   /* This is an association list containing the X selections that
 344      Emacs might own on this terminal.  Each element has the form
 345        (SELECTION-NAME SELECTION-VALUE SELECTION-TIMESTAMP FRAME)
 346      SELECTION-NAME is a lisp symbol, whose name is the name of an X Atom.
 347      SELECTION-VALUE is the value that emacs owns for that selection.
 348       It may be any kind of Lisp object.
 349      SELECTION-TIMESTAMP is the time at which emacs began owning this
 350       selection, as a cons of two 16-bit numbers (making a 32 bit
 351       time.)
 352      FRAME is the frame for which we made the selection.  If there is
 353       an entry in this alist, then it can be assumed that Emacs owns
 354       that selection.
 355      The only (eq) parts of this list that are visible from Lisp are
 356     the selection-values.  */
 357   Lisp_Object Vselection_alist;
 358
 359   /* All fields before `next_terminal' should be Lisp_Object and are traced
 360      by the GC.  All fields afterwards are ignored by the GC.  */
 361
 362   /* Chain of all terminal devices. */
 363   struct terminal *next_terminal;
 364
 365   /* Unique id for this terminal device. */
 366   int id;
 367
 368   /* The number of frames that are on this terminal. */
 369   int reference_count;
 370
 371   /* The type of the terminal device. */
 372   enum output_method type;
 373
 374   /* The name of the terminal device.  Do not use this to uniquely
 375      identify a terminal; the same device may be opened multiple
 376      times. */
 377   char *name;
 378
 379   /* The terminal's keyboard object. */
 380   struct kboard *kboard;
 381
 382 #ifdef HAVE_WINDOW_SYSTEM
 383   /* Cache of images.  */
 384   struct image_cache *image_cache;
 385 #endif /* HAVE_WINDOW_SYSTEM */
 386
 387   /* Device-type dependent data shared amongst all frames on this terminal.  */
 388   union display_info
 389   {
 390     struct tty_display_info *tty;     /* termchar.h */
 391     struct x_display_info *x;         /* xterm.h */
 392     struct w32_display_info *w32;     /* w32term.h */
 393     struct ns_display_info *ns;       /* nsterm.h */
 394   } display_info;
 395
 396 \f
 397   /* Coding-system to be used for encoding terminal output.  This
 398      structure contains information of a coding-system specified by
 399      the function `set-terminal-coding-system'.  Also see
 400      `safe_terminal_coding' in coding.h.  */
 401   struct coding_system *terminal_coding;
 402
 403   /* Coding-system of what is sent from terminal keyboard.  This
 404      structure contains information of a coding-system specified by
 405      the function `set-keyboard-coding-system'.  */
 406   struct coding_system *keyboard_coding;
 407
 408   /* Terminal characteristics.  */
 409   /* XXX Are these really used on non-termcap displays?  */
 410
 411   int must_write_spaces;        /* Nonzero means spaces in the text must
 412                                    actually be output; can't just skip over
 413                                    some columns to leave them blank.  */
 414   int fast_clear_end_of_line;   /* Nonzero means terminal has a `ce' string.  */
 415
 416   int line_ins_del_ok;          /* Terminal can insert and delete lines.  */
 417   int char_ins_del_ok;          /* Terminal can insert and delete chars.  */
 418   int scroll_region_ok;         /* Terminal supports setting the scroll
 419                                    window.  */
 420   int scroll_region_cost;       /* Cost of setting the scroll window,
 421                                    measured in characters.  */
 422   int memory_below_frame;       /* Terminal remembers lines scrolled
 423                                    off bottom.  */
 424
 425   /* Window-based redisplay interface for this device (0 for tty
 426      devices). */
 427   struct redisplay_interface *rif;
 428
 429   /* Frame-based redisplay interface. */
 430
 431   /* Text display hooks.  */
 432
 433   void (*cursor_to_hook) (struct frame *f, int vpos, int hpos);
 434   void (*raw_cursor_to_hook) (struct frame *, int, int);
 435
 436   void (*clear_to_end_hook) (struct frame *);
 437   void (*clear_frame_hook) (struct frame *);
 438   void (*clear_end_of_line_hook) (struct frame *, int);
 439
 440   void (*ins_del_lines_hook) (struct frame *f, int, int);
 441
 442   void (*insert_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 443   void (*write_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 444   void (*delete_glyphs_hook) (struct frame *, int);
 445
 446   void (*ring_bell_hook) (struct frame *f);
 447   void (*toggle_invisible_pointer_hook) (struct frame *f, int invisible);
 448
 449   void (*reset_terminal_modes_hook) (struct terminal *);
 450   void (*set_terminal_modes_hook) (struct terminal *);
 451
 452   void (*update_begin_hook) (struct frame *);
 453   void (*update_end_hook) (struct frame *);
 454   void (*set_terminal_window_hook) (struct frame *, int);
 455
 456   /* Multi-frame and mouse support hooks.  */
 457
 458   /* Return the current position of the mouse.
 459
 460      Set *f to the frame the mouse is in, or zero if the mouse is in no
 461      Emacs frame.  If it is set to zero, all the other arguments are
 462      garbage.
 463
 464      If the motion started in a scroll bar, set *bar_window to the
 465      scroll bar's window, *part to the part the mouse is currently over,
 466      *x to the position of the mouse along the scroll bar, and *y to the
 467      overall length of the scroll bar.
 468
 469      Otherwise, set *bar_window to Qnil, and *x and *y to the column and
 470      row of the character cell the mouse is over.
 471
 472      Set *time to the time the mouse was at the returned position.  */
 473   void (*mouse_position_hook) (struct frame **f, int,
 474                                Lisp_Object *bar_window,
 475                                enum scroll_bar_part *part,
 476                                Lisp_Object *x,
 477                                Lisp_Object *y,
 478                                Time *);
 479
 480   /* When a frame's focus redirection is changed, this hook tells the
 481      window system code to re-decide where to put the highlight.  Under
 482      X, this means that Emacs lies about where the focus is.  */
 483   void (*frame_rehighlight_hook) (struct frame *);
 484
 485   /* If we're displaying frames using a window system that can stack
 486      frames on top of each other, this hook allows you to bring a frame
 487      to the front, or bury it behind all the other windows.  If this
 488      hook is zero, that means the terminal we're displaying on doesn't
 489      support overlapping frames, so there's no need to raise or lower
 490      anything.
 491
 492      If RAISE_FLAG is non-zero, F is brought to the front, before all other
 493      windows.  If RAISE_FLAG is zero, F is sent to the back, behind all other
 494      windows.  */
 495   void (*frame_raise_lower_hook) (struct frame *f, int raise_flag);
 496
 497   /* If the value of the frame parameter changed, whis hook is called.
 498      For example, if going from fullscreen to not fullscreen this hook
 499      may do something OS dependent, like extended window manager hints on X11.  */
 500   void (*fullscreen_hook) (struct frame *f);
 501
 502   \f
 503   /* Scroll bar hooks.  */
 504
 505   /* The representation of scroll bars is determined by the code which
 506      implements them, except for one thing: they must be represented by
 507      lisp objects.  This allows us to place references to them in
 508      Lisp_Windows without worrying about those references becoming
 509      dangling references when the scroll bar is destroyed.
 510
 511      The window-system-independent portion of Emacs just refers to
 512      scroll bars via their windows, and never looks inside the scroll bar
 513      representation; it always uses hook functions to do all the
 514      scroll bar manipulation it needs.
 515
 516      The `vertical_scroll_bar' field of a Lisp_Window refers to that
 517      window's scroll bar, or is nil if the window doesn't have a
 518      scroll bar.
 519
 520      The `scroll_bars' and `condemned_scroll_bars' fields of a Lisp_Frame
 521      are free for use by the scroll bar implementation in any way it sees
 522      fit.  They are marked by the garbage collector.  */
 523
 524
 525   /* Set the vertical scroll bar for WINDOW to have its upper left corner
 526      at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 527      indicate that we are displaying PORTION characters out of a total
 528      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 529      have a scroll bar, create one for it.  */
 530   void (*set_vertical_scroll_bar_hook) (struct window *window,
 531                                         int portion, int whole,
 532                                         int position);
 533
 534
 535   /* The following three hooks are used when we're doing a thorough
 536      redisplay of the frame.  We don't explicitly know which scroll bars
 537      are going to be deleted, because keeping track of when windows go
 538      away is a real pain - can you say set-window-configuration?
 539      Instead, we just assert at the beginning of redisplay that *all*
 540      scroll bars are to be removed, and then save scroll bars from the
 541      fiery pit when we actually redisplay their window.  */
 542
 543   /* Arrange for all scroll bars on FRAME to be removed at the next call
 544      to `*judge_scroll_bars_hook'.  A scroll bar may be spared if
 545      `*redeem_scroll_bar_hook' is applied to its window before the judgment.
 546
 547      This should be applied to each frame each time its window tree is
 548      redisplayed, even if it is not displaying scroll bars at the moment;
 549      if the HAS_SCROLL_BARS flag has just been turned off, only calling
 550      this and the judge_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 (*condemn_scroll_bars_hook) (struct frame *frame);
 556
 557   /* Unmark WINDOW's scroll bar for deletion in this judgment cycle.
 558      Note that it's okay to redeem a scroll bar that is not condemned.  */
 559   void (*redeem_scroll_bar_hook) (struct window *window);
 560
 561   /* Remove all scroll bars on FRAME that haven't been saved since the
 562      last call to `*condemn_scroll_bars_hook'.
 563
 564      This should be applied to each frame after each time its window
 565      tree is redisplayed, even if it is not displaying scroll bars at the
 566      moment; if the HAS_SCROLL_BARS flag has just been turned off, only
 567      calling this and condemn_scroll_bars_hook will get rid of them.
 568
 569      If non-zero, this hook should be safe to apply to any frame,
 570      whether or not it can support scroll bars, and whether or not it is
 571      currently displaying them.  */
 572   void (*judge_scroll_bars_hook) (struct frame *FRAME);
 573
 574 \f
 575   /* Called to read input events.
 576
 577      TERMINAL indicates which terminal device to read from.  Input
 578      events should be read into HOLD_QUIT.
 579
 580      A positive return value indicates that that many input events
 581      were read into BUF.
 582      Zero means no events were immediately available.
 583      A value of -1 means a transient read error, while -2 indicates
 584      that the device was closed (hangup), and it should be deleted.  */
 585   int (*read_socket_hook) (struct terminal *terminal,
 586                            struct input_event *hold_quit);
 587
 588   /* Called when a frame's display becomes entirely up to date.  */
 589   void (*frame_up_to_date_hook) (struct frame *);
 590
 591 \f
 592   /* Called to delete the device-specific portions of a frame that is
 593      on this terminal device. */
 594   void (*delete_frame_hook) (struct frame *);
 595
 596   /* Called after the last frame on this terminal is deleted, or when
 597      the display device was closed (hangup).
 598
 599      If this is NULL, then the generic delete_terminal is called
 600      instead.  Otherwise the hook must call delete_terminal itself.
 601
 602      The hook must check for and close any live frames that are still
 603      on the terminal.  delete_frame ensures that there are no live
 604      frames on the terminal when it calls this hook, so infinite
 605      recursion is prevented.  */
 606   void (*delete_terminal_hook) (struct terminal *);
 607 };
 608
 609 /* Most code should use these functions to set Lisp fields in struct
 610    terminal.  */
 611 TERMHOOKS_INLINE void
 612 tset_charset_list (struct terminal *t, Lisp_Object val)
 613 {
 614   t->charset_list = val;
 615 }
 616 TERMHOOKS_INLINE void
 617 tset_selection_alist (struct terminal *t, Lisp_Object val)
 618 {
 619   t->Vselection_alist = val;
 620 }
 621
 622 /* Chain of all terminal devices currently in use.  */
 623 extern struct terminal *terminal_list;
 624
 625 #define FRAME_MUST_WRITE_SPACES(f) ((f)->terminal->must_write_spaces)
 626 #define FRAME_FAST_CLEAR_END_OF_LINE(f) ((f)->terminal->fast_clear_end_of_line)
 627 #define FRAME_LINE_INS_DEL_OK(f) ((f)->terminal->line_ins_del_ok)
 628 #define FRAME_CHAR_INS_DEL_OK(f) ((f)->terminal->char_ins_del_ok)
 629 #define FRAME_SCROLL_REGION_OK(f) ((f)->terminal->scroll_region_ok)
 630 #define FRAME_SCROLL_REGION_COST(f) ((f)->terminal->scroll_region_cost)
 631 #define FRAME_MEMORY_BELOW_FRAME(f) ((f)->terminal->memory_below_frame)
 632
 633 #define FRAME_TERMINAL_CODING(f) ((f)->terminal->terminal_coding)
 634 #define FRAME_KEYBOARD_CODING(f) ((f)->terminal->keyboard_coding)
 635
 636 #define TERMINAL_TERMINAL_CODING(d) ((d)->terminal_coding)
 637 #define TERMINAL_KEYBOARD_CODING(d) ((d)->keyboard_coding)
 638
 639 #define FRAME_RIF(f) ((f)->terminal->rif)
 640
 641 #define FRAME_TERMINAL(f) ((f)->terminal)
 642
 643 /* Return true if the terminal device is not suspended.  */
 644 #define TERMINAL_ACTIVE_P(d)                                            \
 645   (((d)->type != output_termcap && (d)->type != output_msdos_raw)       \
 646    || (d)->display_info.tty->input)
 647
 648 extern struct terminal *get_terminal (Lisp_Object terminal, bool);
 649 extern struct terminal *create_terminal (void);
 650 extern void delete_terminal (struct terminal *);
 651
 652 /* The initial terminal device, created by initial_term_init.  */
 653 extern struct terminal *initial_terminal;
 654
 655 extern unsigned char *encode_terminal_code (struct glyph *, int,
 656                                             struct coding_system *);
 657
 658 #ifdef HAVE_GPM
 659 extern void close_gpm (int gpm_fd);
 660 #endif
 661
 662 INLINE_HEADER_END