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 "lisp.h"
  27 #include "systime.h" /* for Time */
  28
  29 struct glyph;
  30
  31 INLINE_HEADER_BEGIN
  32
  33 enum scroll_bar_part {
  34   scroll_bar_nowhere,
  35   scroll_bar_above_handle,
  36   scroll_bar_handle,
  37   scroll_bar_below_handle,
  38   scroll_bar_up_arrow,
  39   scroll_bar_down_arrow,
  40   scroll_bar_to_top,
  41   scroll_bar_to_bottom,
  42   scroll_bar_end_scroll,
  43   scroll_bar_move_ratio,
  44   scroll_bar_before_handle,
  45   scroll_bar_horizontal_handle,
  46   scroll_bar_after_handle,
  47   scroll_bar_left_arrow,
  48   scroll_bar_right_arrow,
  49   scroll_bar_to_leftmost,
  50   scroll_bar_to_rightmost
  51 };
  52
  53 /* Output method of a terminal (and frames on this terminal, respectively).  */
  54
  55 enum output_method
  56 {
  57   output_initial,
  58   output_termcap,
  59   output_x_window,
  60   output_msdos_raw,
  61   output_w32,
  62   output_ns
  63 };
  64
  65 /* Input queue declarations and hooks.  */
  66
  67 enum event_kind
  68 {
  69   NO_EVENT,                     /* nothing happened.  This should never
  70                                    actually appear in the event queue.  */
  71
  72   ASCII_KEYSTROKE_EVENT,        /* The ASCII code is in .code, perhaps
  73                                    with modifiers applied.
  74                                    .modifiers holds the state of the
  75                                    modifier keys.
  76                                    .frame_or_window is the frame in
  77                                    which the key was typed.
  78                                    .timestamp gives a timestamp (in
  79                                    milliseconds) for the keystroke.  */
  80   MULTIBYTE_CHAR_KEYSTROKE_EVENT,       /* The multibyte char code is in .code,
  81                                    perhaps with modifiers applied.
  82                                    The others are the same as
  83                                    ASCII_KEYSTROKE_EVENT.  */
  84   NON_ASCII_KEYSTROKE_EVENT,    /* .code is a number identifying the
  85                                    function key.  A code N represents
  86                                    a key whose name is
  87                                    function_key_names[N]; function_key_names
  88                                    is a table in keyboard.c to which you
  89                                    should feel free to add missing keys.
  90                                    .modifiers holds the state of the
  91                                    modifier keys.
  92                                    .frame_or_window is the frame in
  93                                    which the key was typed.
  94                                    .timestamp gives a timestamp (in
  95                                    milliseconds) for the keystroke.  */
  96   TIMER_EVENT,                  /* A timer fired.  */
  97   MOUSE_CLICK_EVENT,            /* The button number is in .code; it must
  98                                    be >= 0 and < NUM_MOUSE_BUTTONS, defined
  99                                    below.
 100                                    .modifiers holds the state of the
 101                                    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 mouse click occurred in.
 106                                    .timestamp gives a timestamp (in
 107                                    milliseconds) for the click.  */
 108   WHEEL_EVENT,                  /* A wheel event is generated by a
 109                                    wheel on a mouse (e.g., MS
 110                                    Intellimouse).
 111                                    .modifiers holds the rotate
 112                                    direction (up or down), and the
 113                                    state of the modifier keys.
 114                                    .x and .y give the mouse position,
 115                                    in characters, within the window.
 116                                    .frame_or_window gives the frame
 117                                    the wheel event occurred in.
 118                                    .timestamp gives a timestamp (in
 119                                    milliseconds) for the event.  */
 120   HORIZ_WHEEL_EVENT,            /* A wheel event generated by a second
 121                                    horizontal wheel that is present on some
 122                                    mice. See WHEEL_EVENT.  */
 123 #ifdef HAVE_NTGUI
 124   LANGUAGE_CHANGE_EVENT,        /* A LANGUAGE_CHANGE_EVENT is
 125                                    generated when HAVE_NTGUI or on Mac OS
 126                                    when the keyboard layout or input
 127                                    language is changed by the
 128                                    user.  */
 129 #endif
 130   SCROLL_BAR_CLICK_EVENT,       /* .code gives the number of the mouse button
 131                                    that was clicked.
 132                                    .modifiers holds the state of the modifier
 133                                    keys.
 134                                    .part is a lisp symbol indicating which
 135                                    part of the scroll bar got clicked.
 136                                    .x gives the distance from the start of the
 137                                    scroll bar of the click; .y gives the total
 138                                    length of the scroll bar.
 139                                    .frame_or_window gives the window
 140                                    whose scroll bar was clicked in.
 141                                    .timestamp gives a timestamp (in
 142                                    milliseconds) for the click.  */
 143   HORIZONTAL_SCROLL_BAR_CLICK_EVENT,    /* .code gives the number of the mouse button
 144                                    that was clicked.
 145                                    .modifiers holds the state of the modifier
 146                                    keys.
 147                                    .part is a lisp symbol indicating which
 148                                    part of the scroll bar got clicked.
 149                                    .x gives the distance from the start of the
 150                                    scroll bar of the click; .y gives the total
 151                                    length of the scroll bar.
 152                                    .frame_or_window gives the window
 153                                    whose scroll bar was clicked in.
 154                                    .timestamp gives a timestamp (in
 155                                    milliseconds) for the click.  */
 156   SELECTION_REQUEST_EVENT,      /* Another X client wants a selection from us.
 157                                    See `struct selection_input_event'.  */
 158   SELECTION_CLEAR_EVENT,        /* Another X client cleared our selection.  */
 159   BUFFER_SWITCH_EVENT,          /* A process filter has switched buffers.  */
 160   DELETE_WINDOW_EVENT,          /* An X client said "delete this window".  */
 161   MENU_BAR_EVENT,               /* An event generated by the menu bar.
 162                                    The frame_or_window field's cdr holds the
 163                                    Lisp-level event value.
 164                                    (Only the toolkit version uses these.)  */
 165   ICONIFY_EVENT,                /* An X client iconified this window.  */
 166   DEICONIFY_EVENT,              /* An X client deiconified this window.  */
 167   MENU_BAR_ACTIVATE_EVENT,      /* A button press in the menu bar
 168                                    (toolkit version only).  */
 169   DRAG_N_DROP_EVENT,            /* A drag-n-drop event is generated when
 170                                    files selected outside of Emacs are dropped
 171                                    onto an Emacs window.
 172                                    .modifiers holds the state of the
 173                                    modifier keys.
 174                                    .x and .y give the mouse position,
 175                                    in characters, within the window.
 176                                    .frame_or_window is the frame in
 177                                    which the drop was made.
 178                                    .arg is a platform-dependent
 179                                    representation of the dropped items.
 180                                    .timestamp gives a timestamp (in
 181                                    milliseconds) for the click.  */
 182   USER_SIGNAL_EVENT,            /* A user signal.
 183                                    code is a number identifying it,
 184                                    index into lispy_user_signals.  */
 185
 186   /* Help events.  Member `frame_or_window' of the input_event is the
 187      frame on which the event occurred, and member `arg' contains
 188      the help to show.  */
 189   HELP_EVENT,
 190
 191   /* An event from a tool-bar.  Member `arg' of the input event
 192      contains the tool-bar item selected.  If `frame_or_window'
 193      and `arg' are equal, this is a prefix event.  */
 194   TOOL_BAR_EVENT,
 195
 196   /* Queued from XTread_socket on FocusIn events.  Translated into
 197      `switch-frame' events in kbd_buffer_get_event, if necessary.  */
 198   FOCUS_IN_EVENT,
 199
 200   FOCUS_OUT_EVENT,
 201
 202   /* Generated when mouse moves over window not currently selected.  */
 203   SELECT_WINDOW_EVENT,
 204
 205   /* Queued from XTread_socket when session manager sends
 206      save yourself before shutdown. */
 207   SAVE_SESSION_EVENT
 208
 209 #ifdef HAVE_GPM
 210   , GPM_CLICK_EVENT
 211 #endif
 212
 213 #ifdef HAVE_DBUS
 214   , DBUS_EVENT
 215 #endif
 216
 217   , CONFIG_CHANGED_EVENT
 218
 219 #ifdef HAVE_NTGUI
 220   /* Generated when an APPCOMMAND event is received, in response to
 221      Multimedia or Internet buttons on some keyboards.
 222      Such keys are available as normal function keys on X through the
 223      Xkeyboard extension.
 224      On Windows, some of them get mapped to normal function key events,
 225      but others need to be handled by APPCOMMAND. Handling them all as
 226      APPCOMMAND events means they can be disabled
 227      (w32-pass-multimedia-buttons-to-system), important on Windows since
 228      the system never sees these keys if Emacs claims to handle them.
 229      On X, the window manager seems to grab the keys it wants
 230      first, so this is not a problem there.  */
 231   , MULTIMEDIA_KEY_EVENT
 232 #endif
 233
 234 #ifdef HAVE_NS
 235   /* Generated when native multi-keystroke input method is used to modify
 236      tentative or indicative text display. */
 237   , NS_TEXT_EVENT
 238   /* Non-key system events (e.g. application menu events) */
 239   , NS_NONKEY_EVENT
 240 #endif
 241
 242 #ifdef USE_FILE_NOTIFY
 243   /* File or directory was changed.  */
 244   , FILE_NOTIFY_EVENT
 245 #endif
 246
 247 };
 248
 249 /* Bit width of an enum event_kind tag at the start of structs and unions.  */
 250 enum { EVENT_KIND_WIDTH = 16 };
 251
 252 /* If a struct input_event has a kind which is SELECTION_REQUEST_EVENT
 253    or SELECTION_CLEAR_EVENT, then its contents are really described
 254    by `struct selection_input_event'; see xterm.h.  */
 255
 256 /* The keyboard input buffer is an array of these structures.  Each one
 257    represents some sort of input event - a keystroke, a mouse click, or
 258    a window system event.  These get turned into their lispy forms when
 259    they are removed from the event queue.  */
 260
 261 struct input_event
 262 {
 263   /* What kind of event was this?  */
 264   ENUM_BF (event_kind) kind : EVENT_KIND_WIDTH;
 265
 266   /* Used in scroll back click events.  */
 267   ENUM_BF (scroll_bar_part) part : 16;
 268
 269   /* For an ASCII_KEYSTROKE_EVENT and MULTIBYTE_CHAR_KEYSTROKE_EVENT,
 270      this is the character.
 271      For a NON_ASCII_KEYSTROKE_EVENT, this is the keysym code.
 272      For a mouse event, this is the button number.  */
 273   unsigned code;
 274
 275   /* See enum below for interpretation.  */
 276   unsigned modifiers;
 277
 278   /* One would prefer C integers, but HELP_EVENT uses these to
 279      record frame or window object and a help form, respectively.  */
 280   Lisp_Object x, y;
 281
 282   /* Usually a time as reported by window system-specific event loop.
 283      For a HELP_EVENT, this is the position within the object (stored
 284      in ARG below) where the help was found.  */
 285   Time timestamp;
 286
 287   /* This field is copied into a vector while the event is in
 288      the queue, so that garbage collections won't kill it.  */
 289   Lisp_Object frame_or_window;
 290
 291   /* This additional argument is used in attempt to avoid extra consing
 292      when building events.  Unfortunately some events have to pass much
 293      more data than it's reasonable to pack directly into this structure.  */
 294   Lisp_Object arg;
 295 };
 296
 297 #define EVENT_INIT(event) memset (&(event), 0, sizeof (struct input_event))
 298
 299 /* Bits in the modifiers member of the input_event structure.
 300    Note that reorder_modifiers assumes that the bits are in canonical
 301    order.
 302
 303    The modifiers applied to mouse clicks are rather ornate.  The
 304    window-system-specific code should store mouse clicks with
 305    up_modifier or down_modifier set.  Having an explicit down modifier
 306    simplifies some of window-system-independent code; without it, the
 307    code would have to recognize down events by checking if the event
 308    is a mouse click lacking the click and drag modifiers.
 309
 310    The window-system independent code turns all up_modifier events
 311    bits into drag_modifier, click_modifier, double_modifier, or
 312    triple_modifier events.  The click_modifier has no written
 313    representation in the names of the symbols used as event heads,
 314    but it does appear in the Qevent_symbol_components property of the
 315    event heads.  */
 316 enum {
 317   up_modifier   =   1,          /* Only used on mouse buttons - always
 318                                    turned into a click or a drag modifier
 319                                    before lisp code sees the event.  */
 320   down_modifier =   2,          /* Only used on mouse buttons.  */
 321   drag_modifier =   4,          /* This is never used in the event
 322                                    queue; it's only used internally by
 323                                    the window-system-independent code.  */
 324   click_modifier=   8,          /* See drag_modifier.  */
 325   double_modifier= 16,          /* See drag_modifier.  */
 326   triple_modifier= 32,          /* See drag_modifier.  */
 327
 328   /* The next four modifier bits are used also in keyboard events at
 329      the Lisp level.
 330
 331      It's probably not the greatest idea to use the 2^28 bit for any
 332      modifier.  It may or may not be the sign bit, depending on
 333      FIXNUM_BITS, so using it to represent a modifier key means that
 334      characters thus modified have different integer equivalents
 335      depending on the architecture they're running on.  Oh, and
 336      applying XINT to a character whose 2^28 bit is set might sign-extend
 337      it, so you get a bunch of bits in the mask you didn't want.
 338
 339      The CHAR_ macros are defined in lisp.h.  */
 340   alt_modifier  =  CHAR_ALT,    /* Under X, the XK_Alt_[LR] keysyms.  */
 341   super_modifier=  CHAR_SUPER,  /* Under X, the XK_Super_[LR] keysyms.  */
 342   hyper_modifier=  CHAR_HYPER,  /* Under X, the XK_Hyper_[LR] keysyms.  */
 343   shift_modifier=  CHAR_SHIFT,
 344   ctrl_modifier =  CHAR_CTL,
 345   meta_modifier =  CHAR_META    /* Under X, the XK_Meta_[LR] keysyms.  */
 346 };
 347
 348 #ifdef HAVE_GPM
 349 #include <gpm.h>
 350 extern int handle_one_term_event (struct tty_display_info *, Gpm_Event *, struct input_event *);
 351 #ifndef HAVE_WINDOW_SYSTEM
 352 extern void term_mouse_moveto (int, int);
 353 #endif
 354
 355 /* The device for which we have enabled gpm support.  */
 356 extern struct tty_display_info *gpm_tty;
 357 #endif
 358
 359 /* Terminal-local parameters. */
 360 struct terminal
 361 {
 362   /* This is for Lisp; the terminal code does not refer to it.  */
 363   struct vectorlike_header header;
 364
 365   /* Parameter alist of this terminal.  */
 366   Lisp_Object param_alist;
 367
 368   /* List of charsets supported by the terminal.  It is set by
 369      Fset_terminal_coding_system_internal along with
 370      the member terminal_coding.  */
 371   Lisp_Object charset_list;
 372
 373   /* This is an association list containing the X selections that
 374      Emacs might own on this terminal.  Each element has the form
 375        (SELECTION-NAME SELECTION-VALUE SELECTION-TIMESTAMP FRAME)
 376      SELECTION-NAME is a lisp symbol, whose name is the name of an X Atom.
 377      SELECTION-VALUE is the value that emacs owns for that selection.
 378       It may be any kind of Lisp object.
 379      SELECTION-TIMESTAMP is the time at which emacs began owning this
 380       selection, as a cons of two 16-bit numbers (making a 32 bit
 381       time.)
 382      FRAME is the frame for which we made the selection.  If there is
 383       an entry in this alist, then it can be assumed that Emacs owns
 384       that selection.
 385      The only (eq) parts of this list that are visible from Lisp are
 386     the selection-values.  */
 387   Lisp_Object Vselection_alist;
 388
 389   /* If a char-table, this maps characters to terminal glyph codes.
 390      If t, the mapping is not available.  If nil, it is not known
 391      whether the mapping is available.  */
 392   Lisp_Object glyph_code_table;
 393
 394   /* All fields before `next_terminal' should be Lisp_Object and are traced
 395      by the GC.  All fields afterwards are ignored by the GC.  */
 396
 397   /* Chain of all terminal devices. */
 398   struct terminal *next_terminal;
 399
 400   /* Unique id for this terminal device. */
 401   int id;
 402
 403   /* The number of frames that are on this terminal. */
 404   int reference_count;
 405
 406   /* The type of the terminal device. */
 407   enum output_method type;
 408
 409   /* The name of the terminal device.  Do not use this to uniquely
 410      identify a terminal; the same device may be opened multiple
 411      times. */
 412   char *name;
 413
 414   /* The terminal's keyboard object. */
 415   struct kboard *kboard;
 416
 417 #ifdef HAVE_WINDOW_SYSTEM
 418   /* Cache of images.  */
 419   struct image_cache *image_cache;
 420 #endif /* HAVE_WINDOW_SYSTEM */
 421
 422   /* Device-type dependent data shared amongst all frames on this terminal.  */
 423   union display_info
 424   {
 425     struct tty_display_info *tty;     /* termchar.h */
 426     struct x_display_info *x;         /* xterm.h */
 427     struct w32_display_info *w32;     /* w32term.h */
 428     struct ns_display_info *ns;       /* nsterm.h */
 429   } display_info;
 430
 431 \f
 432   /* Coding-system to be used for encoding terminal output.  This
 433      structure contains information of a coding-system specified by
 434      the function `set-terminal-coding-system'.  Also see
 435      `safe_terminal_coding' in coding.h.  */
 436   struct coding_system *terminal_coding;
 437
 438   /* Coding-system of what is sent from terminal keyboard.  This
 439      structure contains information of a coding-system specified by
 440      the function `set-keyboard-coding-system'.  */
 441   struct coding_system *keyboard_coding;
 442
 443   /* Window-based redisplay interface for this device (0 for tty
 444      devices). */
 445   struct redisplay_interface *rif;
 446
 447   /* Frame-based redisplay interface. */
 448
 449   /* Text display hooks.  */
 450
 451   void (*cursor_to_hook) (struct frame *f, int vpos, int hpos);
 452   void (*raw_cursor_to_hook) (struct frame *, int, int);
 453
 454   void (*clear_to_end_hook) (struct frame *);
 455   void (*clear_frame_hook) (struct frame *);
 456   void (*clear_end_of_line_hook) (struct frame *, int);
 457
 458   void (*ins_del_lines_hook) (struct frame *f, int, int);
 459
 460   void (*insert_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 461   void (*write_glyphs_hook) (struct frame *f, struct glyph *s, int n);
 462   void (*delete_glyphs_hook) (struct frame *, int);
 463
 464   void (*ring_bell_hook) (struct frame *f);
 465   void (*toggle_invisible_pointer_hook) (struct frame *f, bool invisible);
 466
 467   void (*reset_terminal_modes_hook) (struct terminal *);
 468   void (*set_terminal_modes_hook) (struct terminal *);
 469
 470   void (*update_begin_hook) (struct frame *);
 471   void (*update_end_hook) (struct frame *);
 472   void (*set_terminal_window_hook) (struct frame *, int);
 473
 474   /* Multi-frame and mouse support hooks.  */
 475
 476   /* Return the current position of the mouse.
 477
 478      Set *f to the frame the mouse is in, or zero if the mouse is in no
 479      Emacs frame.  If it is set to zero, all the other arguments are
 480      garbage.
 481
 482      If the motion started in a scroll bar, set *bar_window to the
 483      scroll bar's window, *part to the part the mouse is currently over,
 484      *x to the position of the mouse along the scroll bar, and *y to the
 485      overall length of the scroll bar.
 486
 487      Otherwise, set *bar_window to Qnil, and *x and *y to the column and
 488      row of the character cell the mouse is over.
 489
 490      Set *time to the time the mouse was at the returned position.  */
 491   void (*mouse_position_hook) (struct frame **f, int,
 492                                Lisp_Object *bar_window,
 493                                enum scroll_bar_part *part,
 494                                Lisp_Object *x,
 495                                Lisp_Object *y,
 496                                Time *);
 497
 498   /* When a frame's focus redirection is changed, this hook tells the
 499      window system code to re-decide where to put the highlight.  Under
 500      X, this means that Emacs lies about where the focus is.  */
 501   void (*frame_rehighlight_hook) (struct frame *);
 502
 503   /* If we're displaying frames using a window system that can stack
 504      frames on top of each other, this hook allows you to bring a frame
 505      to the front, or bury it behind all the other windows.  If this
 506      hook is zero, that means the terminal we're displaying on doesn't
 507      support overlapping frames, so there's no need to raise or lower
 508      anything.
 509
 510      If RAISE_FLAG, F is brought to the front, before all other
 511      windows.  If !RAISE_FLAG, F is sent to the back, behind all other
 512      windows.  */
 513   void (*frame_raise_lower_hook) (struct frame *f, bool raise_flag);
 514
 515   /* If the value of the frame parameter changed, this hook is called.
 516      For example, if going from fullscreen to not fullscreen this hook
 517      may do something OS dependent, like extended window manager hints on X11.  */
 518   void (*fullscreen_hook) (struct frame *f);
 519
 520   /* This hook is called to display menus.  */
 521   Lisp_Object (*menu_show_hook) (struct frame *f, int x, int y, int menuflags,
 522                                  Lisp_Object title, const char **error_name);
 523
 524   /* This hook is called to display popup dialog.  */
 525   Lisp_Object (*popup_dialog_hook) (struct frame *f, Lisp_Object header,
 526                                     Lisp_Object contents);
 527
 528   /* Scroll bar hooks.  */
 529
 530   /* The representation of scroll bars is determined by the code which
 531      implements them, except for one thing: they must be represented by
 532      lisp objects.  This allows us to place references to them in
 533      Lisp_Windows without worrying about those references becoming
 534      dangling references when the scroll bar is destroyed.
 535
 536      The window-system-independent portion of Emacs just refers to
 537      scroll bars via their windows, and never looks inside the scroll bar
 538      representation; it always uses hook functions to do all the
 539      scroll bar manipulation it needs.
 540
 541      The `vertical_scroll_bar' field of a Lisp_Window refers to that
 542      window's scroll bar, or is nil if the window doesn't have a
 543      scroll bar.
 544
 545      The `scroll_bars' and `condemned_scroll_bars' fields of a Lisp_Frame
 546      are free for use by the scroll bar implementation in any way it sees
 547      fit.  They are marked by the garbage collector.  */
 548
 549
 550   /* Set the vertical scroll bar for WINDOW to have its upper left corner
 551      at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 552      indicate that we are displaying PORTION characters out of a total
 553      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 554      have a scroll bar, create one for it.  */
 555   void (*set_vertical_scroll_bar_hook) (struct window *window,
 556                                         int portion, int whole,
 557                                         int position);
 558
 559
 560   /* Set the horizontal scroll bar for WINDOW to have its upper left
 561      corner at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
 562      indicate that we are displaying PORTION characters out of a total
 563      of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
 564      have a scroll bar, create one for it.  */
 565   void (*set_horizontal_scroll_bar_hook) (struct window *window,
 566                                           int portion, int whole,
 567                                           int position);
 568
 569
 570   /* The following three hooks are used when we're doing a thorough
 571      redisplay of the frame.  We don't explicitly know which scroll bars
 572      are going to be deleted, because keeping track of when windows go
 573      away is a real pain - can you say set-window-configuration?
 574      Instead, we just assert at the beginning of redisplay that *all*
 575      scroll bars are to be removed, and then save scroll bars from the
 576      fiery pit when we actually redisplay their window.  */
 577
 578   /* Arrange for all scroll bars on FRAME to be removed at the next call
 579      to `*judge_scroll_bars_hook'.  A scroll bar may be spared if
 580      `*redeem_scroll_bar_hook' is applied to its window before the judgment.
 581
 582      This should be applied to each frame each time its window tree is
 583      redisplayed, even if it is not displaying scroll bars at the moment;
 584      if the HAS_SCROLL_BARS flag has just been turned off, only calling
 585      this and the judge_scroll_bars_hook will get rid of them.
 586
 587      If non-zero, this hook should be safe to apply to any frame,
 588      whether or not it can support scroll bars, and whether or not it is
 589      currently displaying them.  */
 590   void (*condemn_scroll_bars_hook) (struct frame *frame);
 591
 592   /* Unmark WINDOW's scroll bar for deletion in this judgment cycle.
 593      Note that it's okay to redeem a scroll bar that is not condemned.  */
 594   void (*redeem_scroll_bar_hook) (struct window *window);
 595
 596   /* Remove all scroll bars on FRAME that haven't been saved since the
 597      last call to `*condemn_scroll_bars_hook'.
 598
 599      This should be applied to each frame after each time its window
 600      tree is redisplayed, even if it is not displaying scroll bars at the
 601      moment; if the HAS_SCROLL_BARS flag has just been turned off, only
 602      calling this and condemn_scroll_bars_hook will get rid of them.
 603
 604      If non-zero, this hook should be safe to apply to any frame,
 605      whether or not it can support scroll bars, and whether or not it is
 606      currently displaying them.  */
 607   void (*judge_scroll_bars_hook) (struct frame *FRAME);
 608
 609 \f
 610   /* Called to read input events.
 611
 612      TERMINAL indicates which terminal device to read from.  Input
 613      events should be read into HOLD_QUIT.
 614
 615      A positive return value indicates that that many input events
 616      were read into BUF.
 617      Zero means no events were immediately available.
 618      A value of -1 means a transient read error, while -2 indicates
 619      that the device was closed (hangup), and it should be deleted.  */
 620   int (*read_socket_hook) (struct terminal *terminal,
 621                            struct input_event *hold_quit);
 622
 623   /* Called when a frame's display becomes entirely up to date.  */
 624   void (*frame_up_to_date_hook) (struct frame *);
 625
 626 \f
 627   /* Called to delete the device-specific portions of a frame that is
 628      on this terminal device. */
 629   void (*delete_frame_hook) (struct frame *);
 630
 631   /* Called after the last frame on this terminal is deleted, or when
 632      the display device was closed (hangup).
 633
 634      If this is NULL, then the generic delete_terminal is called
 635      instead.  Otherwise the hook must call delete_terminal itself.
 636
 637      The hook must check for and close any live frames that are still
 638      on the terminal.  delete_frame ensures that there are no live
 639      frames on the terminal when it calls this hook, so infinite
 640      recursion is prevented.  */
 641   void (*delete_terminal_hook) (struct terminal *);
 642 };
 643
 644 /* Most code should use these functions to set Lisp fields in struct
 645    terminal.  */
 646 INLINE void
 647 tset_charset_list (struct terminal *t, Lisp_Object val)
 648 {
 649   t->charset_list = val;
 650 }
 651 INLINE void
 652 tset_selection_alist (struct terminal *t, Lisp_Object val)
 653 {
 654   t->Vselection_alist = val;
 655 }
 656
 657 /* Chain of all terminal devices currently in use.  */
 658 extern struct terminal *terminal_list;
 659
 660 #define FRAME_MUST_WRITE_SPACES(f) (FRAME_TTY (f)->must_write_spaces)
 661 #define FRAME_LINE_INS_DEL_OK(f) (FRAME_TTY (f)->line_ins_del_ok)
 662 #define FRAME_CHAR_INS_DEL_OK(f) (FRAME_TTY (f)->char_ins_del_ok)
 663 #define FRAME_SCROLL_REGION_OK(f) (FRAME_TTY (f)->scroll_region_ok)
 664 #define FRAME_SCROLL_REGION_COST(f) (FRAME_TTY (f)->scroll_region_cost)
 665 #define FRAME_MEMORY_BELOW_FRAME(f) (FRAME_TTY (f)->memory_below_frame)
 666
 667 #define FRAME_TERMINAL_CODING(f) ((f)->terminal->terminal_coding)
 668 #define FRAME_KEYBOARD_CODING(f) ((f)->terminal->keyboard_coding)
 669
 670 #define TERMINAL_TERMINAL_CODING(d) ((d)->terminal_coding)
 671 #define TERMINAL_KEYBOARD_CODING(d) ((d)->keyboard_coding)
 672
 673 #define FRAME_RIF(f) ((f)->terminal->rif)
 674
 675 #define FRAME_TERMINAL(f) ((f)->terminal)
 676
 677 /* Return true if the terminal device is not suspended.  */
 678 #define TERMINAL_ACTIVE_P(d)                                            \
 679   (((d)->type != output_termcap && (d)->type != output_msdos_raw)       \
 680    || (d)->display_info.tty->input)
 681
 682 /* Return font cache data for the specified terminal.  The historical
 683    name is grossly misleading, actually it is (NAME . FONT-LIST-CACHE).  */
 684 #if defined (HAVE_X_WINDOWS)
 685 #define TERMINAL_FONT_CACHE(t)                                          \
 686   (t->type == output_x_window ? t->display_info.x->name_list_element : Qnil)
 687 #elif defined (HAVE_NTGUI)
 688 #define TERMINAL_FONT_CACHE(t)                                          \
 689   (t->type == output_w32 ? t->display_info.w32->name_list_element : Qnil)
 690 #elif defined (HAVE_NS)
 691 #define TERMINAL_FONT_CACHE(t)                                          \
 692   (t->type == output_ns ? t->display_info.ns->name_list_element : Qnil)
 693 #endif
 694
 695 extern struct terminal *decode_live_terminal (Lisp_Object);
 696 extern struct terminal *decode_tty_terminal (Lisp_Object);
 697 extern struct terminal *get_named_terminal (const char *);
 698 extern struct terminal *create_terminal (enum output_method,
 699                                          struct redisplay_interface *);
 700 extern void delete_terminal (struct terminal *);
 701 extern Lisp_Object terminal_glyph_code (struct terminal *, int);
 702
 703 /* The initial terminal device, created by initial_term_init.  */
 704 extern struct terminal *initial_terminal;
 705
 706 extern unsigned char *encode_terminal_code (struct glyph *, int,
 707                                             struct coding_system *);
 708
 709 #ifdef HAVE_GPM
 710 extern void close_gpm (int gpm_fd);
 711 #endif
 712
 713 #ifdef WINDOWSNT
 714 extern int cursorX (struct tty_display_info *);
 715 extern int cursorY (struct tty_display_info *);
 716 #else
 717 #define cursorX(t)  curX(t)
 718 #define cursorY(t)  curY(t)
 719 #endif
 720
 721 INLINE_HEADER_END
 722
 723 #endif /* EMACS_TERMHOOKS_H */