src/termhooks.h

   1 /* Parameters and display hooks for terminal devices.
   2
   3 Copyright (C) 1985-1986, 1993-1994, 2001-2015 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 #ifndef EMACS_TERMHOOKS_H
  22 #define EMACS_TERMHOOKS_H
  23
  24 /* Miscellanea.   */
  25
  26 #include "systime.h" /* for Time */
  27
  28 INLINE_HEADER_BEGIN
  29
  30 enum scroll_bar_part {
  31   scroll_bar_nowhere,
  32   scroll_bar_above_handle,
  33   scroll_bar_handle,
  34   scroll_bar_below_handle,
  35   scroll_bar_up_arrow,
  36   scroll_bar_down_arrow,
  37   scroll_bar_to_top,
  38   scroll_bar_to_bottom,
  39   scroll_bar_end_scroll,
  40   scroll_bar_move_ratio,
  41   scroll_bar_before_handle,
  42   scroll_bar_horizontal_handle,
  43   scroll_bar_after_handle,
  44   scroll_bar_left_arrow,
  45   scroll_bar_right_arrow,
  46   scroll_bar_to_leftmost,
  47   scroll_bar_to_rightmost
  48 };
  49
  50 /* Output method of a terminal (and frames on this terminal, respectively).  */
  51
  52 enum output_method
  53 {
  54   output_initial,
  55   output_termcap,
  56   output_x_window,
  57   output_msdos_raw,
  58   output_w32,
  59   output_ns
  60 };
  61
  62 /* Input queue declarations and hooks.  */
  63
  64 enum event_kind
  65 {
  66   NO_EVENT,                     /* nothing happened.  This should never
  67                                    actually appear in the event queue.  */
  68
  69   ASCII_KEYSTROKE_EVENT,        /* The ASCII code is in .code, perhaps
  70                                    with modifiers applied.
  71                                    .modifiers holds the state of the
  72                                    modifier keys.
  73                                    .frame_or_window is the frame in
  74                                    which the key was typed.
  75                                    .timestamp gives a timestamp (in
  76                                    milliseconds) for the keystroke.  */
  77   MULTIBYTE_CHAR_KEYSTROKE_EVENT,       /* The multibyte char code is in .code,
  78                                    perhaps with modifiers applied.
  79                                    The others are the same as
  80                                    ASCII_KEYSTROKE_EVENT.  */
  81   NON_ASCII_KEYSTROKE_EVENT,    /* .code is a number identifying the
  82                                    function key.  A code N represents
  83                                    a key whose name is
  84                                    function_key_names[N]; function_key_names
  85                                    is a table in keyboard.c to which you
  86                                    should feel free to add missing keys.
  87                                    .modifiers holds the state of the
  88                                    modifier keys.
  89                                    .frame_or_window is the frame in
  90                                    which the key was typed.
  91                                    .timestamp gives a timestamp (in
  92                                    milliseconds) for the keystroke.  */
  93   TIMER_EVENT,                  /* A timer fired.  */
  94   MOUSE_CLICK_EVENT,            /* The button number is in .code; it must
  95                                    be >= 0 and < NUM_MOUSE_BUTTONS, defined
  96                                    below.
  97                                    .modifiers holds the state of the
  98                                    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 mouse click occurred in.
 103                                    .timestamp gives a timestamp (in
 104                                    milliseconds) for the click.  */
 105   WHEEL_EVENT,                  /* A wheel event is generated by a
 106                                    wheel on a mouse (e.g., MS
 107                                    Intellimouse).
 108                                    .modifiers holds the rotate
 109                                    direction (up or down), and the
 110                                    state of the modifier keys.
 111                                    .x and .y give the mouse position,
 112                                    in characters, within the window.
 113                                    .frame_or_window gives the frame
 114                                    the wheel event occurred in.
 115                                    .timestamp gives a timestamp (in
 116                                    milliseconds) for the event.  */
 117   HORIZ_WHEEL_EVENT,            /* A wheel event generated by a second
 118                                    horizontal wheel that is present on some
 119                                    mice. See WHEEL_EVENT.  */
 120 #ifdef HAVE_NTGUI
 121   LANGUAGE_CHANGE_EVENT,        /* A LANGUAGE_CHANGE_EVENT is
 122                                    generated when HAVE_NTGUI or on Mac OS
 123                                    when the keyboard layout or input
 124                                    language is changed by the
 125                                    user.  */
 126 #endif
 127   SCROLL_BAR_CLICK_EVENT,       /* .code gives the number of the mouse button
 128                                    that was clicked.
 129                                    .modifiers holds the state of the modifier
 130                                    keys.
 131                                    .part is a lisp symbol indicating which
 132                                    part of the scroll bar got clicked.
 133                                    .x gives the distance from the start of the
 134                                    scroll bar of the click; .y gives the total
 135                                    length of the scroll bar.
 136                                    .frame_or_window gives the window
 137                                    whose scroll bar was clicked in.
 138                                    .timestamp gives a timestamp (in
 139                                    milliseconds) for the click.  */
 140   HORIZONTAL_SCROLL_BAR_CLICK_EVENT,    /* .code gives the number of the mouse button
 141                                    that was clicked.
 142                                    .modifiers holds the state of the modifier
 143                                    keys.
 144                                    .part is a lisp symbol indicating which
 145                                    part of the scroll bar got clicked.
 146                                    .x gives the distance from the start of the
 147                                    scroll bar of the click; .y gives the total
 148                                    length of the scroll bar.
 149                                    .frame_or_window gives the window
 150                                    whose scroll bar was clicked in.
 151                                    .timestamp gives a timestamp (in
 152                                    milliseconds) for the click.  */
 153   SELECTION_REQUEST_EVENT,      /* Another X client wants a selection from us.
 154                                    See `struct selection_input_event'.  */
 155   SELECTION_CLEAR_EVENT,        /* Another X client cleared our selection.  */
 156   BUFFER_SWITCH_EVENT,          /* A process filter has switched buffers.  */
 157   DELETE_WINDOW_EVENT,          /* An X client said "delete this window".  */
 158   MENU_BAR_EVENT,               /* An event generated by the menu bar.
 159                                    The frame_or_window field's cdr holds the
 160                                    Lisp-level event value.
 161                                    (Only the toolkit version uses these.)  */
 162   ICONIFY_EVENT,                /* An X client iconified this window.  */
 163   DEICONIFY_EVENT,              /* An X client deiconified this window.  */
 164   MENU_BAR_ACTIVATE_EVENT,      /* A button press in the menu bar
 165                                    (toolkit version only).  */
 166   DRAG_N_DROP_EVENT,            /* A drag-n-drop event is generated when
 167                                    files selected outside of Emacs are dropped
 168                                    onto an Emacs window.
 169                                    .modifiers holds the state of the
 170                                    modifier keys.
 171                                    .x and .y give the mouse position,
 172                                    in characters, within the window.
 173                                    .frame_or_window is the frame in
 174                                    which the drop was made.
 175                                    .arg is a platform-dependent
 176                                    representation of the dropped items.
 177                                    .timestamp gives a timestamp (in
 178                                    milliseconds) for the click.  */
 179   USER_SIGNAL_EVENT,            /* A user signal.
 180                                    code is a number identifying it,
 181                                    index into lispy_user_signals.  */
 182
 183   /* Help events.  Member `frame_or_window' of the input_event is the
 184      frame on which the event occurred, and member `arg' contains
 185      the help to show.  */
 186   HELP_EVENT,
 187
 188   /* An event from a tool-bar.  Member `arg' of the input event
 189      contains the tool-bar item selected.  If `frame_or_window'
 190      and `arg' are equal, this is a prefix event.  */
 191   TOOL_BAR_EVENT,
 192
 193   /* Queued from XTread_socket on FocusIn events.  Translated into
 194      `switch-frame' events in kbd_buffer_get_event, if necessary.  */
 195   FOCUS_IN_EVENT,
 196
 197   FOCUS_OUT_EVENT,
 198
 199   /* Generated when mouse moves over window not currently selected.  */
 200   SELECT_WINDOW_EVENT,
 201
 202   /* Queued from XTread_socket when session manager sends
 203      save yourself before shutdown. */
 204   SAVE_SESSION_EVENT
 205
 206 #ifdef HAVE_GPM
 207   , GPM_CLICK_EVENT
 208 #endif
 209
 210 #ifdef HAVE_DBUS
 211   , DBUS_EVENT
 212 #endif
 213
 214   , CONFIG_CHANGED_EVENT
 215
 216 #ifdef HAVE_NTGUI
 217   /* Generated when an APPCOMMAND event is received, in response to
 218      Multimedia or Internet buttons on some keyboards.
 219      Such keys are available as normal function keys on X through the
 220      Xkeyboard extension.
 221      On Windows, some of them get mapped to normal function key events,
 222      but others need to be handled by APPCOMMAND. Handling them all as
 223      APPCOMMAND events means they can be disabled
 224      (w32-pass-multimedia-buttons-to-system), important on Windows since
 225      the system never sees these keys if Emacs claims to handle them.
 226      On X, the window manager seems to grab the keys it wants
 227      first, so this is not a problem there.  */
 228   , MULTIMEDIA_KEY_EVENT
 229 #endif
 230
 231 #ifdef HAVE_NS
 232   /* Generated when native multi-keystroke input method is used to modify
 233      tentative or indicative text display. */
 234   , NS_TEXT_EVENT
 235   /* Non-key system events (e.g. application menu events) */
 236   , NS_NONKEY_EVENT
 237 #endif
 238
 239 #ifdef USE_FILE_NOTIFY
 240   /* File or directory was changed.  */
 241   , FILE_NOTIFY_EVENT
 242 #endif
 243
 244 };
 245
 246 /* If a struct input_event has a kind which is SELECTION_REQUEST_EVENT
 247    or SELECTION_CLEAR_EVENT, then its contents are really described
 248    by `struct selection_input_event'; see xterm.h.  */
 249
 250 /* The keyboard input buffer is an array of these structures.  Each one
 251    represents some sort of input event - a keystroke, a mouse click, or
 252    a window system event.  These get turned into their lispy forms when
 253    they are removed from the event queue.  */
 254
 255 struct input_event
 256 {
 257   /* What kind of event was this?  */
 258   ENUM_BF (event_kind) kind : 16;
 259
 260   /* Used in scroll back click events.  */
 261   ENUM_BF (scroll_bar_part) part : 16;
 262
 263   /* For an ASCII_KEYSTROKE_EVENT and MULTIBYTE_CHAR_KEYSTROKE_EVENT,
 264      this is the character.
 265      For a NON_ASCII_KEYSTROKE_EVENT, this is the keysym code.
 266      For a mouse event, this is the button number.  */
 267   unsigned code;
 268
 269   /* See enum below for interpretation.  */
 270   unsigned modifiers;
 271
 272   /* One would prefer C integers, but HELP_EVENT uses these to
 273      record frame or window object and a help form, respectively.  */
 274   Lisp_Object x, y;
 275
 276   /* Usually a time as reported by window system-specific event loop.
 277      For a HELP_EVENT, this is the position within the object (stored
 278      in ARG below) where the help was found.  */
 279   Time timestamp;
 280
 281   /* This field is copied into a vector while the event is in
 282      the queue, so that garbage collections won't kill it.  */
 283   Lisp_Object frame_or_window;
 284
 285   /* This additional argument is used in attempt to avoid extra consing
 286      when building events.  Unfortunately some events have to pass much
 287      more data than it's reasonable to pack directly into this structure.  */
 288   Lisp_Object arg;
 289 };
 290
 291 #define EVENT_INIT(event) memset (&(event), 0, sizeof (struct input_event))
 292
 293 /* Bits in the modifiers member of the input_event structure.
 294    Note that reorder_modifiers assumes that the bits are in canonical
 295    order.
 296
 297    The modifiers applied to mouse clicks are rather ornate.  The
 298    window-system-specific code should store mouse clicks with
 299    up_modifier or down_modifier set.  Having an explicit down modifier
 300    simplifies some of window-system-independent code; without it, the
 301    code would have to recognize down events by checking if the event
 302    is a mouse click lacking the click and drag modifiers.
 303
 304    The window-system independent code turns all up_modifier events
 305    bits into drag_modifier, click_modifier, double_modifier, or
 306    triple_modifier events.  The click_modifier has no written
 307    representation in the names of the symbols used as event heads,
 308    but it does appear in the Qevent_symbol_components property of the
 309    event heads.  */
 310 enum {
 311   up_modifier   =   1,          /* Only used on mouse buttons - always
 312                                    turned into a click or a drag modifier
 313                                    before lisp code sees the event.  */
 314   down_modifier =   2,          /* Only used on mouse buttons.  */
 315   drag_modifier =   4,          /* This is never used in the event
 316                                    queue; it's only used internally by
 317                                    the window-system-independent code.  */
 318   click_modifier=   8,          /* See drag_modifier.  */
 319   double_modifier= 16,          /* See drag_modifier.  */
 320   triple_modifier= 32,          /* See drag_modifier.  */
 321
 322   /* The next four modifier bits are used also in keyboard events at
 323      the Lisp level.
 324
 325      It's probably not the greatest idea to use the 2^28 bit for any
 326      modifier.  It may or may not be the sign bit, depending on
 327      FIXNUM_BITS, so using it to represent a modifier key means that
 328      characters thus modified have different integer equivalents
 329      depending on the architecture they're running on.  Oh, and
 330      applying XINT to a character whose 2^28 bit is set might sign-extend
 331      it, so you get a bunch of bits in the mask you didn't want.
 332
 333      The CHAR_ macros are defined in lisp.h.  */
 334   alt_modifier  =  CHAR_ALT,    /* Under X, the XK_Alt_[LR] keysyms.  */
 335   super_modifier=  CHAR_SUPER,  /* Under X, the XK_Super_[LR] keysyms.  */
 336   hyper_modifier=  CHAR_HYPER,  /* Under X, the XK_Hyper_[LR] keysyms.  */
 337   shift_modifier=  CHAR_SHIFT,
 338   ctrl_modifier =  CHAR_CTL,
 339   meta_modifier =  CHAR_META    /* Under X, the XK_Meta_[LR] keysyms.  */
 340 };
 341
 342 #ifdef HAVE_GPM
 343 #include <gpm.h>
 344 extern int handle_one_term_event (struct tty_display_info *, Gpm_Event *, struct input_event *);
 345 #ifndef HAVE_WINDOW_SYSTEM
 346 extern void term_mouse_moveto (int, int);
 347 #endif
 348
 349 /* The device for which we have enabled gpm support.  */
 350 extern struct tty_display_info *gpm_tty;
 351 #endif
 352
 353 /* Terminal-local parameters. */
 354 struct terminal
 355 {
 356   /* This is for Lisp; the terminal code does not refer to it.  */
 357   struct vectorlike_header header;
 358
 359   /* Parameter alist of this terminal.  */
 360   Lisp_Object param_alist;
 361
 362   /* List of charsets supported by the terminal.  It is set by
 363      Fset_terminal_coding_system_internal along with
 364      the member terminal_coding.  */
 365   Lisp_Object charset_list;
 366
 367   /* This is an association list containing the X selections that
 368      Emacs might own on this terminal.  Each element has the form
 369        (SELECTION-NAME SELECTION-VALUE SELECTION-TIMESTAMP FRAME)
 370      SELECTION-NAME is a lisp symbol, whose name is the name of an X Atom.
 371      SELECTION-VALUE is the value that emacs owns for that selection.
 372       It may be any kind of Lisp object.
 373      SELECTION-TIMESTAMP is the time at which emacs began owning this
 374       selection, as a cons of two 16-bit numbers (making a 32 bit
 375       time.)
 376      FRAME is the frame for which we made the selection.  If there is
 377       an entry in this alist, then it can be assumed that Emacs owns
 378       that selection.
 379      The only (eq) parts of this list that are visible from Lisp are
 380     the selection-values.  */
 381   Lisp_Object Vselection_alist;
 382
 383   /* All fields before `next_terminal' should be Lisp_Object and are traced
 384      by the GC.  All fields afterwards are ignored by the GC.  */
 385
 386   /* Chain of all terminal devices. */
 387   struct terminal *next_terminal;
 388
 389   /* Unique id for this terminal device. */
 390   int id;
 391
 392   /* The number of frames that are on this terminal. */
 393   int reference_count;
 394
 395   /* The type of the terminal device. */
 396   enum output_method type;
 397
 398   /* The name of the terminal device.  Do not use this to uniquely
 399      identify a terminal; the same device may be opened multiple
 400      times. */
 401   char *name;
 402
 403   /* The terminal's keyboard object. */
 404   struct kboard *kboard;
 405
 406 #ifdef HAVE_WINDOW_SYSTEM
 407   /* Cache of images.  */
 408   struct image_cache *image_cache;
 409 #endif /* HAVE_WINDOW_SYSTEM */
 410
 411   /* Device-type dependent data shared amongst all frames on this terminal.  */
 412   union display_info
 413   {
 414     struct tty_display_info *tty;     /* termchar.h */
 415     struct x_display_info *x;         /* xterm.h */
 416     struct w32_display_info *w32;     /* w32term.h */
 417     struct ns_display_info *ns;       /* nsterm.h */
 418   } display_info;
 419
 420 \f
 421   /* Coding-system to be used for encoding terminal output.  This
 422      structure contains information of a coding-system specified by
 423      the function `set-terminal-coding-system'.  Also see
 424      `safe_terminal_coding' in coding.h.  */
 425   struct coding_system *terminal_coding;
 426
 427   /* Coding-system of what is sent from terminal keyboard.  This
 428      structure contains information of a coding-system specified by
 429      the function `set-keyboard-coding-system'.  */
 430   struct coding_system *keyboard_coding;
 431
 432   /* Window-based redisplay interface for this device (0 for tty
 433      devices). */
 434   struct redisplay_interface *rif;
 435
 436   /* Frame-based redisplay interface. */
 437
 438   /* Text display hooks.  */
 439
 440   void (*cursor_to_hook) (struct frame *f, int vpos, int hpos);
 441   void (*raw_cursor_to_hook) (struct frame *, int, int);
 442
 443   void (*clear_to_end_hook) (struct frame *);
 444   void (*clear_frame_hook) (struct frame *);
 445   void (*clear_end_of_line_hook) (struct frame *, int);
 446
 447   void (*ins_del_lines_hook) (struct frame *f, int, int);
 448
 449   void (*insert_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 450   void (*write_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 451   void (*delete_glyphs_hook) (struct frame *, int);
 452
 453   void (*ring_bell_hook) (struct frame *f);
 454   void (*toggle_invisible_pointer_hook) (struct frame *f, bool invisible);
 455
 456   void (*reset_terminal_modes_hook) (struct terminal *);
 457   void (*set_terminal_modes_hook) (struct terminal *);
 458
 459   void (*update_begin_hook) (struct frame *);
 460   void (*update_end_hook) (struct frame *);
 461   void (*set_terminal_window_hook) (struct frame *, int);
 462
 463   /* Multi-frame and mouse support hooks.  */
 464
 465   /* Return the current position of the mouse.
 466
 467      Set *f to the frame the mouse is in, or zero if the mouse is in no
 468      Emacs frame.  If it is set to zero, all the other arguments are
 469      garbage.
 470
 471      If the motion started in a scroll bar, set *bar_window to the
 472      scroll bar's window, *part to the part the mouse is currently over,
 473      *x to the position of the mouse along the scroll bar, and *y to the
 474      overall length of the scroll bar.
 475
 476      Otherwise, set *bar_window to Qnil, and *x and *y to the column and
 477      row of the character cell the mouse is over.
 478
 479      Set *time to the time the mouse was at the returned position.  */
 480   void (*mouse_position_hook) (struct frame **f, int,
 481                                Lisp_Object *bar_window,
 482                                enum scroll_bar_part *part,
 483                                Lisp_Object *x,
 484                                Lisp_Object *y,
 485                                Time *);
 486
 487   /* When a frame's focus redirection is changed, this hook tells the
 488      window system code to re-decide where to put the highlight.  Under
 489      X, this means that Emacs lies about where the focus is.  */
 490   void (*frame_rehighlight_hook) (struct frame *);
 491
 492   /* If we're displaying frames using a window system that can stack
 493      frames on top of each other, this hook allows you to bring a frame
 494      to the front, or bury it behind all the other windows.  If this
 495      hook is zero, that means the terminal we're displaying on doesn't
 496      support overlapping frames, so there's no need to raise or lower
 497      anything.
 498
 499      If RAISE_FLAG, F is brought to the front, before all other
 500      windows.  If !RAISE_FLAG, F is sent to the back, behind all other
 501      windows.  */
 502   void (*frame_raise_lower_hook) (struct frame *f, bool raise_flag);
 503
 504   /* If the value of the frame parameter changed, this hook is called.
 505      For example, if going from fullscreen to not fullscreen this hook
 506      may do something OS dependent, like extended window manager hints on X11.  */
 507   void (*fullscreen_hook) (struct frame *f);
 508
 509   /* This hook is called to display menus.  */
 510   Lisp_Object (*menu_show_hook) (struct frame *f, int x, int y, int menuflags,
 511                                  Lisp_Object title, const char **error_name);
 512
 513   /* This hook is called to display popup dialog.  */
 514   Lisp_Object (*popup_dialog_hook) (struct frame *f, Lisp_Object header,
 515                                     Lisp_Object contents);
 516
 517   /* Scroll bar hooks.  */
 518
 519   /* The representation of scroll bars is determined by the code which
 520      implements them, except for one thing: they must be represented by
 521      lisp objects.  This allows us to place references to them in
 522      Lisp_Windows without worrying about those references becoming
 523      dangling references when the scroll bar is destroyed.
 524
 525      The window-system-independent portion of Emacs just refers to
 526      scroll bars via their windows, and never looks inside the scroll bar
 527      representation; it always uses hook functions to do all the
 528      scroll bar manipulation it needs.
 529
 530      The `vertical_scroll_bar' field of a Lisp_Window refers to that
 531      window's scroll bar, or is nil if the window doesn't have a
 532      scroll bar.
 533
 534      The `scroll_bars' and `condemned_scroll_bars' fields of a Lisp_Frame
 535      are free for use by the scroll bar implementation in any way it sees
 536      fit.  They are marked by the garbage collector.  */
 537
 538
 539   /* Set the vertical scroll bar for WINDOW to have its upper left corner
 540      at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 541      indicate that we are displaying PORTION characters out of a total
 542      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 543      have a scroll bar, create one for it.  */
 544   void (*set_vertical_scroll_bar_hook) (struct window *window,
 545                                         int portion, int whole,
 546                                         int position);
 547
 548
 549   /* Set the horizontal scroll bar for WINDOW to have its upper left
 550      corner at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 551      indicate that we are displaying PORTION characters out of a total
 552      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 553      have a scroll bar, create one for it.  */
 554   void (*set_horizontal_scroll_bar_hook) (struct window *window,
 555                                           int portion, int whole,
 556                                           int position);
 557
 558
 559   /* The following three hooks are used when we're doing a thorough
 560      redisplay of the frame.  We don't explicitly know which scroll bars
 561      are going to be deleted, because keeping track of when windows go
 562      away is a real pain - can you say set-window-configuration?
 563      Instead, we just assert at the beginning of redisplay that *all*
 564      scroll bars are to be removed, and then save scroll bars from the
 565      fiery pit when we actually redisplay their window.  */
 566
 567   /* Arrange for all scroll bars on FRAME to be removed at the next call
 568      to `*judge_scroll_bars_hook'.  A scroll bar may be spared if
 569      `*redeem_scroll_bar_hook' is applied to its window before the judgment.
 570
 571      This should be applied to each frame each time its window tree is
 572      redisplayed, even if it is not displaying scroll bars at the moment;
 573      if the HAS_SCROLL_BARS flag has just been turned off, only calling
 574      this and the judge_scroll_bars_hook will get rid of them.
 575
 576      If non-zero, this hook should be safe to apply to any frame,
 577      whether or not it can support scroll bars, and whether or not it is
 578      currently displaying them.  */
 579   void (*condemn_scroll_bars_hook) (struct frame *frame);
 580
 581   /* Unmark WINDOW's scroll bar for deletion in this judgment cycle.
 582      Note that it's okay to redeem a scroll bar that is not condemned.  */
 583   void (*redeem_scroll_bar_hook) (struct window *window);
 584
 585   /* Remove all scroll bars on FRAME that haven't been saved since the
 586      last call to `*condemn_scroll_bars_hook'.
 587
 588      This should be applied to each frame after each time its window
 589      tree is redisplayed, even if it is not displaying scroll bars at the
 590      moment; if the HAS_SCROLL_BARS flag has just been turned off, only
 591      calling this and condemn_scroll_bars_hook will get rid of them.
 592
 593      If non-zero, this hook should be safe to apply to any frame,
 594      whether or not it can support scroll bars, and whether or not it is
 595      currently displaying them.  */
 596   void (*judge_scroll_bars_hook) (struct frame *FRAME);
 597
 598 \f
 599   /* Called to read input events.
 600
 601      TERMINAL indicates which terminal device to read from.  Input
 602      events should be read into HOLD_QUIT.
 603
 604      A positive return value indicates that that many input events
 605      were read into BUF.
 606      Zero means no events were immediately available.
 607      A value of -1 means a transient read error, while -2 indicates
 608      that the device was closed (hangup), and it should be deleted.  */
 609   int (*read_socket_hook) (struct terminal *terminal,
 610                            struct input_event *hold_quit);
 611
 612   /* Called when a frame's display becomes entirely up to date.  */
 613   void (*frame_up_to_date_hook) (struct frame *);
 614
 615 \f
 616   /* Called to delete the device-specific portions of a frame that is
 617      on this terminal device. */
 618   void (*delete_frame_hook) (struct frame *);
 619
 620   /* Called after the last frame on this terminal is deleted, or when
 621      the display device was closed (hangup).
 622
 623      If this is NULL, then the generic delete_terminal is called
 624      instead.  Otherwise the hook must call delete_terminal itself.
 625
 626      The hook must check for and close any live frames that are still
 627      on the terminal.  delete_frame ensures that there are no live
 628      frames on the terminal when it calls this hook, so infinite
 629      recursion is prevented.  */
 630   void (*delete_terminal_hook) (struct terminal *);
 631 };
 632
 633 /* Most code should use these functions to set Lisp fields in struct
 634    terminal.  */
 635 INLINE void
 636 tset_charset_list (struct terminal *t, Lisp_Object val)
 637 {
 638   t->charset_list = val;
 639 }
 640 INLINE void
 641 tset_selection_alist (struct terminal *t, Lisp_Object val)
 642 {
 643   t->Vselection_alist = val;
 644 }
 645
 646 /* Chain of all terminal devices currently in use.  */
 647 extern struct terminal *terminal_list;
 648
 649 #define FRAME_MUST_WRITE_SPACES(f) (FRAME_TTY (f)->must_write_spaces)
 650 #define FRAME_LINE_INS_DEL_OK(f) (FRAME_TTY (f)->line_ins_del_ok)
 651 #define FRAME_CHAR_INS_DEL_OK(f) (FRAME_TTY (f)->char_ins_del_ok)
 652 #define FRAME_SCROLL_REGION_OK(f) (FRAME_TTY (f)->scroll_region_ok)
 653 #define FRAME_SCROLL_REGION_COST(f) (FRAME_TTY (f)->scroll_region_cost)
 654 #define FRAME_MEMORY_BELOW_FRAME(f) (FRAME_TTY (f)->memory_below_frame)
 655
 656 #define FRAME_TERMINAL_CODING(f) ((f)->terminal->terminal_coding)
 657 #define FRAME_KEYBOARD_CODING(f) ((f)->terminal->keyboard_coding)
 658
 659 #define TERMINAL_TERMINAL_CODING(d) ((d)->terminal_coding)
 660 #define TERMINAL_KEYBOARD_CODING(d) ((d)->keyboard_coding)
 661
 662 #define FRAME_RIF(f) ((f)->terminal->rif)
 663
 664 #define FRAME_TERMINAL(f) ((f)->terminal)
 665
 666 /* Return true if the terminal device is not suspended.  */
 667 #define TERMINAL_ACTIVE_P(d)                                            \
 668   (((d)->type != output_termcap && (d)->type != output_msdos_raw)       \
 669    || (d)->display_info.tty->input)
 670
 671 /* Return font cache data for the specified terminal.  The historical
 672    name is grossly misleading, actually it is (NAME . FONT-LIST-CACHE).  */
 673 #if defined (HAVE_X_WINDOWS)
 674 #define TERMINAL_FONT_CACHE(t)                                          \
 675   (t->type == output_x_window ? t->display_info.x->name_list_element : Qnil)
 676 #elif defined (HAVE_NTGUI)
 677 #define TERMINAL_FONT_CACHE(t)                                          \
 678   (t->type == output_w32 ? t->display_info.w32->name_list_element : Qnil)
 679 #elif defined (HAVE_NS)
 680 #define TERMINAL_FONT_CACHE(t)                                          \
 681   (t->type == output_ns ? t->display_info.ns->name_list_element : Qnil)
 682 #endif
 683
 684 extern struct terminal *decode_live_terminal (Lisp_Object);
 685 extern struct terminal *decode_tty_terminal (Lisp_Object);
 686 extern struct terminal *get_named_terminal (const char *);
 687 extern struct terminal *create_terminal (enum output_method,
 688                                          struct redisplay_interface *);
 689 extern void delete_terminal (struct terminal *);
 690
 691 /* The initial terminal device, created by initial_term_init.  */
 692 extern struct terminal *initial_terminal;
 693
 694 extern unsigned char *encode_terminal_code (struct glyph *, int,
 695                                             struct coding_system *);
 696
 697 #ifdef HAVE_GPM
 698 extern void close_gpm (int gpm_fd);
 699 #endif
 700
 701 #ifdef WINDOWSNT
 702 extern int cursorX (struct tty_display_info *);
 703 extern int cursorY (struct tty_display_info *);
 704 #else
 705 #define cursorX(t)  curX(t)
 706 #define cursorY(t)  curY(t)
 707 #endif
 708
 709 INLINE_HEADER_END
 710
 711 #endif /* EMACS_TERMHOOKS_H */