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 HAVE_XWIDGETS
 240   /* events generated by xwidgets*/
 241    , XWIDGET_EVENT
 242 #endif
 243 #ifdef USE_FILE_NOTIFY
 244   /* File or directory was changed.  */
 245   , FILE_NOTIFY_EVENT
 246 #endif
 247
 248 };
 249
 250 /* If a struct input_event has a kind which is SELECTION_REQUEST_EVENT
 251    or SELECTION_CLEAR_EVENT, then its contents are really described
 252    by `struct selection_input_event'; see xterm.h.  */
 253
 254 /* The keyboard input buffer is an array of these structures.  Each one
 255    represents some sort of input event - a keystroke, a mouse click, or
 256    a window system event.  These get turned into their lispy forms when
 257    they are removed from the event queue.  */
 258
 259 struct input_event
 260 {
 261   /* What kind of event was this?  */
 262   ENUM_BF (event_kind) kind : 16;
 263
 264   /* Used in scroll back click events.  */
 265   ENUM_BF (scroll_bar_part) part : 16;
 266
 267   /* For an ASCII_KEYSTROKE_EVENT and MULTIBYTE_CHAR_KEYSTROKE_EVENT,
 268      this is the character.
 269      For a NON_ASCII_KEYSTROKE_EVENT, this is the keysym code.
 270      For a mouse event, this is the button number.  */
 271   unsigned code;
 272
 273   /* See enum below for interpretation.  */
 274   unsigned modifiers;
 275
 276   /* One would prefer C integers, but HELP_EVENT uses these to
 277      record frame or window object and a help form, respectively.  */
 278   Lisp_Object x, y;
 279
 280   /* Usually a time as reported by window system-specific event loop.
 281      For a HELP_EVENT, this is the position within the object (stored
 282      in ARG below) where the help was found.  */
 283   Time timestamp;
 284
 285   /* This field is copied into a vector while the event is in
 286      the queue, so that garbage collections won't kill it.  */
 287   Lisp_Object frame_or_window;
 288
 289   /* This additional argument is used in attempt to avoid extra consing
 290      when building events.  Unfortunately some events have to pass much
 291      more data than it's reasonable to pack directly into this structure.  */
 292   Lisp_Object arg;
 293 };
 294
 295 #define EVENT_INIT(event) memset (&(event), 0, sizeof (struct input_event))
 296
 297 /* Bits in the modifiers member of the input_event structure.
 298    Note that reorder_modifiers assumes that the bits are in canonical
 299    order.
 300
 301    The modifiers applied to mouse clicks are rather ornate.  The
 302    window-system-specific code should store mouse clicks with
 303    up_modifier or down_modifier set.  Having an explicit down modifier
 304    simplifies some of window-system-independent code; without it, the
 305    code would have to recognize down events by checking if the event
 306    is a mouse click lacking the click and drag modifiers.
 307
 308    The window-system independent code turns all up_modifier events
 309    bits into drag_modifier, click_modifier, double_modifier, or
 310    triple_modifier events.  The click_modifier has no written
 311    representation in the names of the symbols used as event heads,
 312    but it does appear in the Qevent_symbol_components property of the
 313    event heads.  */
 314 enum {
 315   up_modifier   =   1,          /* Only used on mouse buttons - always
 316                                    turned into a click or a drag modifier
 317                                    before lisp code sees the event.  */
 318   down_modifier =   2,          /* Only used on mouse buttons.  */
 319   drag_modifier =   4,          /* This is never used in the event
 320                                    queue; it's only used internally by
 321                                    the window-system-independent code.  */
 322   click_modifier=   8,          /* See drag_modifier.  */
 323   double_modifier= 16,          /* See drag_modifier.  */
 324   triple_modifier= 32,          /* See drag_modifier.  */
 325
 326   /* The next four modifier bits are used also in keyboard events at
 327      the Lisp level.
 328
 329      It's probably not the greatest idea to use the 2^28 bit for any
 330      modifier.  It may or may not be the sign bit, depending on
 331      FIXNUM_BITS, so using it to represent a modifier key means that
 332      characters thus modified have different integer equivalents
 333      depending on the architecture they're running on.  Oh, and
 334      applying XINT to a character whose 2^28 bit is set might sign-extend
 335      it, so you get a bunch of bits in the mask you didn't want.
 336
 337      The CHAR_ macros are defined in lisp.h.  */
 338   alt_modifier  =  CHAR_ALT,    /* Under X, the XK_Alt_[LR] keysyms.  */
 339   super_modifier=  CHAR_SUPER,  /* Under X, the XK_Super_[LR] keysyms.  */
 340   hyper_modifier=  CHAR_HYPER,  /* Under X, the XK_Hyper_[LR] keysyms.  */
 341   shift_modifier=  CHAR_SHIFT,
 342   ctrl_modifier =  CHAR_CTL,
 343   meta_modifier =  CHAR_META    /* Under X, the XK_Meta_[LR] keysyms.  */
 344 };
 345
 346 #ifdef HAVE_GPM
 347 #include <gpm.h>
 348 extern int handle_one_term_event (struct tty_display_info *, Gpm_Event *, struct input_event *);
 349 #ifndef HAVE_WINDOW_SYSTEM
 350 extern void term_mouse_moveto (int, int);
 351 #endif
 352
 353 /* The device for which we have enabled gpm support.  */
 354 extern struct tty_display_info *gpm_tty;
 355 #endif
 356
 357 /* Terminal-local parameters. */
 358 struct terminal
 359 {
 360   /* This is for Lisp; the terminal code does not refer to it.  */
 361   struct vectorlike_header header;
 362
 363   /* Parameter alist of this terminal.  */
 364   Lisp_Object param_alist;
 365
 366   /* List of charsets supported by the terminal.  It is set by
 367      Fset_terminal_coding_system_internal along with
 368      the member terminal_coding.  */
 369   Lisp_Object charset_list;
 370
 371   /* This is an association list containing the X selections that
 372      Emacs might own on this terminal.  Each element has the form
 373        (SELECTION-NAME SELECTION-VALUE SELECTION-TIMESTAMP FRAME)
 374      SELECTION-NAME is a lisp symbol, whose name is the name of an X Atom.
 375      SELECTION-VALUE is the value that emacs owns for that selection.
 376       It may be any kind of Lisp object.
 377      SELECTION-TIMESTAMP is the time at which emacs began owning this
 378       selection, as a cons of two 16-bit numbers (making a 32 bit
 379       time.)
 380      FRAME is the frame for which we made the selection.  If there is
 381       an entry in this alist, then it can be assumed that Emacs owns
 382       that selection.
 383      The only (eq) parts of this list that are visible from Lisp are
 384     the selection-values.  */
 385   Lisp_Object Vselection_alist;
 386
 387   /* All fields before `next_terminal' should be Lisp_Object and are traced
 388      by the GC.  All fields afterwards are ignored by the GC.  */
 389
 390   /* Chain of all terminal devices. */
 391   struct terminal *next_terminal;
 392
 393   /* Unique id for this terminal device. */
 394   int id;
 395
 396   /* The number of frames that are on this terminal. */
 397   int reference_count;
 398
 399   /* The type of the terminal device. */
 400   enum output_method type;
 401
 402   /* The name of the terminal device.  Do not use this to uniquely
 403      identify a terminal; the same device may be opened multiple
 404      times. */
 405   char *name;
 406
 407   /* The terminal's keyboard object. */
 408   struct kboard *kboard;
 409
 410 #ifdef HAVE_WINDOW_SYSTEM
 411   /* Cache of images.  */
 412   struct image_cache *image_cache;
 413 #endif /* HAVE_WINDOW_SYSTEM */
 414
 415   /* Device-type dependent data shared amongst all frames on this terminal.  */
 416   union display_info
 417   {
 418     struct tty_display_info *tty;     /* termchar.h */
 419     struct x_display_info *x;         /* xterm.h */
 420     struct w32_display_info *w32;     /* w32term.h */
 421     struct ns_display_info *ns;       /* nsterm.h */
 422   } display_info;
 423
 424 \f
 425   /* Coding-system to be used for encoding terminal output.  This
 426      structure contains information of a coding-system specified by
 427      the function `set-terminal-coding-system'.  Also see
 428      `safe_terminal_coding' in coding.h.  */
 429   struct coding_system *terminal_coding;
 430
 431   /* Coding-system of what is sent from terminal keyboard.  This
 432      structure contains information of a coding-system specified by
 433      the function `set-keyboard-coding-system'.  */
 434   struct coding_system *keyboard_coding;
 435
 436   /* Window-based redisplay interface for this device (0 for tty
 437      devices). */
 438   struct redisplay_interface *rif;
 439
 440   /* Frame-based redisplay interface. */
 441
 442   /* Text display hooks.  */
 443
 444   void (*cursor_to_hook) (struct frame *f, int vpos, int hpos);
 445   void (*raw_cursor_to_hook) (struct frame *, int, int);
 446
 447   void (*clear_to_end_hook) (struct frame *);
 448   void (*clear_frame_hook) (struct frame *);
 449   void (*clear_end_of_line_hook) (struct frame *, int);
 450
 451   void (*ins_del_lines_hook) (struct frame *f, int, int);
 452
 453   void (*insert_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 454   void (*write_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 455   void (*delete_glyphs_hook) (struct frame *, int);
 456
 457   void (*ring_bell_hook) (struct frame *f);
 458   void (*toggle_invisible_pointer_hook) (struct frame *f, bool invisible);
 459
 460   void (*reset_terminal_modes_hook) (struct terminal *);
 461   void (*set_terminal_modes_hook) (struct terminal *);
 462
 463   void (*update_begin_hook) (struct frame *);
 464   void (*update_end_hook) (struct frame *);
 465   void (*set_terminal_window_hook) (struct frame *, int);
 466
 467   /* Multi-frame and mouse support hooks.  */
 468
 469   /* Return the current position of the mouse.
 470
 471      Set *f to the frame the mouse is in, or zero if the mouse is in no
 472      Emacs frame.  If it is set to zero, all the other arguments are
 473      garbage.
 474
 475      If the motion started in a scroll bar, set *bar_window to the
 476      scroll bar's window, *part to the part the mouse is currently over,
 477      *x to the position of the mouse along the scroll bar, and *y to the
 478      overall length of the scroll bar.
 479
 480      Otherwise, set *bar_window to Qnil, and *x and *y to the column and
 481      row of the character cell the mouse is over.
 482
 483      Set *time to the time the mouse was at the returned position.  */
 484   void (*mouse_position_hook) (struct frame **f, int,
 485                                Lisp_Object *bar_window,
 486                                enum scroll_bar_part *part,
 487                                Lisp_Object *x,
 488                                Lisp_Object *y,
 489                                Time *);
 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, F is brought to the front, before all other
 504      windows.  If !RAISE_FLAG, F is sent to the back, behind all other
 505      windows.  */
 506   void (*frame_raise_lower_hook) (struct frame *f, bool raise_flag);
 507
 508   /* If the value of the frame parameter changed, this 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   /* This hook is called to display menus.  */
 514   Lisp_Object (*menu_show_hook) (struct frame *f, int x, int y, int menuflags,
 515                                  Lisp_Object title, const char **error_name);
 516
 517   /* This hook is called to display popup dialog.  */
 518   Lisp_Object (*popup_dialog_hook) (struct frame *f, Lisp_Object header,
 519                                     Lisp_Object contents);
 520
 521   /* Scroll bar hooks.  */
 522
 523   /* The representation of scroll bars is determined by the code which
 524      implements them, except for one thing: they must be represented by
 525      lisp objects.  This allows us to place references to them in
 526      Lisp_Windows without worrying about those references becoming
 527      dangling references when the scroll bar is destroyed.
 528
 529      The window-system-independent portion of Emacs just refers to
 530      scroll bars via their windows, and never looks inside the scroll bar
 531      representation; it always uses hook functions to do all the
 532      scroll bar manipulation it needs.
 533
 534      The `vertical_scroll_bar' field of a Lisp_Window refers to that
 535      window's scroll bar, or is nil if the window doesn't have a
 536      scroll bar.
 537
 538      The `scroll_bars' and `condemned_scroll_bars' fields of a Lisp_Frame
 539      are free for use by the scroll bar implementation in any way it sees
 540      fit.  They are marked by the garbage collector.  */
 541
 542
 543   /* Set the vertical scroll bar for WINDOW to have its upper left corner
 544      at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 545      indicate that we are displaying PORTION characters out of a total
 546      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 547      have a scroll bar, create one for it.  */
 548   void (*set_vertical_scroll_bar_hook) (struct window *window,
 549                                         int portion, int whole,
 550                                         int position);
 551
 552
 553   /* Set the horizontal scroll bar for WINDOW to have its upper left
 554      corner at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 555      indicate that we are displaying PORTION characters out of a total
 556      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 557      have a scroll bar, create one for it.  */
 558   void (*set_horizontal_scroll_bar_hook) (struct window *window,
 559                                           int portion, int whole,
 560                                           int position);
 561
 562
 563   /* The following three hooks are used when we're doing a thorough
 564      redisplay of the frame.  We don't explicitly know which scroll bars
 565      are going to be deleted, because keeping track of when windows go
 566      away is a real pain - can you say set-window-configuration?
 567      Instead, we just assert at the beginning of redisplay that *all*
 568      scroll bars are to be removed, and then save scroll bars from the
 569      fiery pit when we actually redisplay their window.  */
 570
 571   /* Arrange for all scroll bars on FRAME to be removed at the next call
 572      to `*judge_scroll_bars_hook'.  A scroll bar may be spared if
 573      `*redeem_scroll_bar_hook' is applied to its window before the judgment.
 574
 575      This should be applied to each frame each time its window tree is
 576      redisplayed, even if it is not displaying scroll bars at the moment;
 577      if the HAS_SCROLL_BARS flag has just been turned off, only calling
 578      this and the judge_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 (*condemn_scroll_bars_hook) (struct frame *frame);
 584
 585   /* Unmark WINDOW's scroll bar for deletion in this judgment cycle.
 586      Note that it's okay to redeem a scroll bar that is not condemned.  */
 587   void (*redeem_scroll_bar_hook) (struct window *window);
 588
 589   /* Remove all scroll bars on FRAME that haven't been saved since the
 590      last call to `*condemn_scroll_bars_hook'.
 591
 592      This should be applied to each frame after each time its window
 593      tree is redisplayed, even if it is not displaying scroll bars at the
 594      moment; if the HAS_SCROLL_BARS flag has just been turned off, only
 595      calling this and condemn_scroll_bars_hook will get rid of them.
 596
 597      If non-zero, this hook should be safe to apply to any frame,
 598      whether or not it can support scroll bars, and whether or not it is
 599      currently displaying them.  */
 600   void (*judge_scroll_bars_hook) (struct frame *FRAME);
 601
 602 \f
 603   /* Called to read input events.
 604
 605      TERMINAL indicates which terminal device to read from.  Input
 606      events should be read into HOLD_QUIT.
 607
 608      A positive return value indicates that that many input events
 609      were read into BUF.
 610      Zero means no events were immediately available.
 611      A value of -1 means a transient read error, while -2 indicates
 612      that the device was closed (hangup), and it should be deleted.  */
 613   int (*read_socket_hook) (struct terminal *terminal,
 614                            struct input_event *hold_quit);
 615
 616   /* Called when a frame's display becomes entirely up to date.  */
 617   void (*frame_up_to_date_hook) (struct frame *);
 618
 619 \f
 620   /* Called to delete the device-specific portions of a frame that is
 621      on this terminal device. */
 622   void (*delete_frame_hook) (struct frame *);
 623
 624   /* Called after the last frame on this terminal is deleted, or when
 625      the display device was closed (hangup).
 626
 627      If this is NULL, then the generic delete_terminal is called
 628      instead.  Otherwise the hook must call delete_terminal itself.
 629
 630      The hook must check for and close any live frames that are still
 631      on the terminal.  delete_frame ensures that there are no live
 632      frames on the terminal when it calls this hook, so infinite
 633      recursion is prevented.  */
 634   void (*delete_terminal_hook) (struct terminal *);
 635 };
 636
 637 /* Most code should use these functions to set Lisp fields in struct
 638    terminal.  */
 639 INLINE void
 640 tset_charset_list (struct terminal *t, Lisp_Object val)
 641 {
 642   t->charset_list = val;
 643 }
 644 INLINE void
 645 tset_selection_alist (struct terminal *t, Lisp_Object val)
 646 {
 647   t->Vselection_alist = val;
 648 }
 649
 650 /* Chain of all terminal devices currently in use.  */
 651 extern struct terminal *terminal_list;
 652
 653 #define FRAME_MUST_WRITE_SPACES(f) (FRAME_TTY (f)->must_write_spaces)
 654 #define FRAME_LINE_INS_DEL_OK(f) (FRAME_TTY (f)->line_ins_del_ok)
 655 #define FRAME_CHAR_INS_DEL_OK(f) (FRAME_TTY (f)->char_ins_del_ok)
 656 #define FRAME_SCROLL_REGION_OK(f) (FRAME_TTY (f)->scroll_region_ok)
 657 #define FRAME_SCROLL_REGION_COST(f) (FRAME_TTY (f)->scroll_region_cost)
 658 #define FRAME_MEMORY_BELOW_FRAME(f) (FRAME_TTY (f)->memory_below_frame)
 659
 660 #define FRAME_TERMINAL_CODING(f) ((f)->terminal->terminal_coding)
 661 #define FRAME_KEYBOARD_CODING(f) ((f)->terminal->keyboard_coding)
 662
 663 #define TERMINAL_TERMINAL_CODING(d) ((d)->terminal_coding)
 664 #define TERMINAL_KEYBOARD_CODING(d) ((d)->keyboard_coding)
 665
 666 #define FRAME_RIF(f) ((f)->terminal->rif)
 667
 668 #define FRAME_TERMINAL(f) ((f)->terminal)
 669
 670 /* Return true if the terminal device is not suspended.  */
 671 #define TERMINAL_ACTIVE_P(d)                                            \
 672   (((d)->type != output_termcap && (d)->type != output_msdos_raw)       \
 673    || (d)->display_info.tty->input)
 674
 675 /* Return font cache data for the specified terminal.  The historical
 676    name is grossly misleading, actually it is (NAME . FONT-LIST-CACHE).  */
 677 #if defined (HAVE_X_WINDOWS)
 678 #define TERMINAL_FONT_CACHE(t)                                          \
 679   (t->type == output_x_window ? t->display_info.x->name_list_element : Qnil)
 680 #elif defined (HAVE_NTGUI)
 681 #define TERMINAL_FONT_CACHE(t)                                          \
 682   (t->type == output_w32 ? t->display_info.w32->name_list_element : Qnil)
 683 #elif defined (HAVE_NS)
 684 #define TERMINAL_FONT_CACHE(t)                                          \
 685   (t->type == output_ns ? t->display_info.ns->name_list_element : Qnil)
 686 #endif
 687
 688 extern struct terminal *decode_live_terminal (Lisp_Object);
 689 extern struct terminal *decode_tty_terminal (Lisp_Object);
 690 extern struct terminal *get_named_terminal (const char *);
 691 extern struct terminal *create_terminal (enum output_method,
 692                                          struct redisplay_interface *);
 693 extern void delete_terminal (struct terminal *);
 694
 695 /* The initial terminal device, created by initial_term_init.  */
 696 extern struct terminal *initial_terminal;
 697
 698 extern unsigned char *encode_terminal_code (struct glyph *, int,
 699                                             struct coding_system *);
 700
 701 #ifdef HAVE_GPM
 702 extern void close_gpm (int gpm_fd);
 703 #endif
 704
 705 #ifdef WINDOWSNT
 706 extern int cursorX (struct tty_display_info *);
 707 extern int cursorY (struct tty_display_info *);
 708 #else
 709 #define cursorX(t)  curX(t)
 710 #define cursorY(t)  curY(t)
 711 #endif
 712
 713 INLINE_HEADER_END
 714
 715 #endif /* EMACS_TERMHOOKS_H */