Add GCC-style 'const' attribute to functions that can use it.
[bpt/emacs.git] / src / keyboard.h
1 /* Declarations useful when processing input.
2 Copyright (C) 1985-1987, 1993, 2001-2012 Free Software Foundation, Inc.
3
4 This file is part of GNU Emacs.
5
6 GNU Emacs is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
10
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
18
19 #include "systime.h" /* for EMACS_TIME, Time */
20 #include "coding.h" /* for ENCODE_UTF_8 and ENCODE_SYSTEM */
21
22 /* Lisp fields in struct keyboard are hidden from most code and accessed
23 via the KVAR macro, below. Only select pieces of code, like the GC,
24 are allowed to use KBOARD_INTERNAL_FIELD. */
25 #define KBOARD_INTERNAL_FIELD(field) field ## _
26
27 /* Most code should use this macro to access Lisp fields in struct
28 kboard. */
29 #define KVAR(kboard, field) ((kboard)->KBOARD_INTERNAL_FIELD (field))
30
31 /* Each KBOARD represents one logical input stream from which Emacs
32 gets input. If we are using ordinary terminals, it has one KBOARD
33 object for each terminal device.
34 Usually each X display screen has its own KBOARD,
35 but when two of them are on the same X server,
36 we assume they share a keyboard and give them one KBOARD in common.
37
38 Some Lisp variables are per-kboard; they are stored in the KBOARD structure
39 and accessed indirectly via a Lisp_Misc_Kboard_Objfwd object.
40
41 So that definition of keyboard macros, and reading of prefix arguments,
42 can happen in parallel on various KBOARDs at once,
43 the state information for those activities is stored in the KBOARD.
44
45 Emacs has two states for reading input:
46
47 ** Any kboard. Emacs can accept input from any KBOARD,
48 and as soon as any of them provides a complete command, Emacs can run it.
49
50 ** Single kboard. Then Emacs is running a command for one KBOARD
51 and can only read input from that KBOARD.
52
53 All input, from all KBOARDs, goes together in a single event queue
54 at interrupt level. read_char sees the events sequentially,
55 but deals with them in accord with the current input state.
56
57 In the any-kboard state, read_key_sequence processes input from any KBOARD
58 immediately. When a new event comes in from a particular KBOARD,
59 read_key_sequence switches to that KBOARD. As a result,
60 as soon as a complete key arrives from some KBOARD or other,
61 Emacs starts executing that key's binding. It switches to the
62 single-kboard state for the execution of that command,
63 so that that command can get input only from its own KBOARD.
64
65 While in the single-kboard state, read_char can consider input only
66 from the current KBOARD. If events come from other KBOARDs, they
67 are put aside for later in the KBOARDs' kbd_queue lists.
68 The flag kbd_queue_has_data in a KBOARD is 1 if this has happened.
69 When Emacs goes back to the any-kboard state, it looks at all the KBOARDs
70 to find those; and it tries processing their input right away. */
71
72 typedef struct kboard KBOARD;
73 struct kboard
74 {
75 KBOARD *next_kboard;
76
77 /* If non-nil, a keymap that overrides all others but applies only to
78 this KBOARD. Lisp code that uses this instead of calling read-char
79 can effectively wait for input in the any-kboard state, and hence
80 avoid blocking out the other KBOARDs. See universal-argument in
81 lisp/simple.el for an example. */
82 Lisp_Object KBOARD_INTERNAL_FIELD (Voverriding_terminal_local_map);
83
84 /* Last command executed by the editor command loop, not counting
85 commands that set the prefix argument. */
86 Lisp_Object KBOARD_INTERNAL_FIELD (Vlast_command);
87
88 /* Normally same as last-command, but never modified by other commands. */
89 Lisp_Object KBOARD_INTERNAL_FIELD (Vreal_last_command);
90
91 /* User-supplied table to translate input characters through. */
92 Lisp_Object KBOARD_INTERNAL_FIELD (Vkeyboard_translate_table);
93
94 /* Last command that may be repeated by `repeat'. */
95 Lisp_Object KBOARD_INTERNAL_FIELD (Vlast_repeatable_command);
96
97 /* The prefix argument for the next command, in raw form. */
98 Lisp_Object KBOARD_INTERNAL_FIELD (Vprefix_arg);
99
100 /* Saved prefix argument for the last command, in raw form. */
101 Lisp_Object KBOARD_INTERNAL_FIELD (Vlast_prefix_arg);
102
103 /* Unread events specific to this kboard. */
104 Lisp_Object KBOARD_INTERNAL_FIELD (kbd_queue);
105
106 /* Non-nil while a kbd macro is being defined. */
107 Lisp_Object KBOARD_INTERNAL_FIELD (defining_kbd_macro);
108
109 /* The start of storage for the current keyboard macro. */
110 Lisp_Object *kbd_macro_buffer;
111
112 /* Where to store the next keystroke of the macro. */
113 Lisp_Object *kbd_macro_ptr;
114
115 /* The finalized section of the macro starts at kbd_macro_buffer and
116 ends before this. This is not the same as kbd_macro_ptr, because
117 we advance this to kbd_macro_ptr when a key's command is complete.
118 This way, the keystrokes for "end-kbd-macro" are not included in the
119 macro. This also allows us to throw away the events added to the
120 macro by the last command: all the events between kbd_macro_end and
121 kbd_macro_ptr belong to the last command; see
122 cancel-kbd-macro-events. */
123 Lisp_Object *kbd_macro_end;
124
125 /* Allocated size of kbd_macro_buffer. */
126 ptrdiff_t kbd_macro_bufsize;
127
128 /* Last anonymous kbd macro defined. */
129 Lisp_Object KBOARD_INTERNAL_FIELD (Vlast_kbd_macro);
130
131 /* Alist of system-specific X windows key symbols. */
132 Lisp_Object KBOARD_INTERNAL_FIELD (Vsystem_key_alist);
133
134 /* Cache for modify_event_symbol. */
135 Lisp_Object KBOARD_INTERNAL_FIELD (system_key_syms);
136
137 /* The kind of display: x, w32, ... */
138 Lisp_Object KBOARD_INTERNAL_FIELD (Vwindow_system);
139
140 /* Keymap mapping keys to alternative preferred forms.
141 See the DEFVAR for more documentation. */
142 Lisp_Object KBOARD_INTERNAL_FIELD (Vlocal_function_key_map);
143
144 /* Keymap mapping ASCII function key sequences onto their preferred
145 forms. Initialized by the terminal-specific lisp files. See the
146 DEFVAR for more documentation. */
147 Lisp_Object KBOARD_INTERNAL_FIELD (Vinput_decode_map);
148
149 /* Minibufferless frames on this display use this frame's minibuffer. */
150 Lisp_Object KBOARD_INTERNAL_FIELD (Vdefault_minibuffer_frame);
151
152 /* Number of displays using this KBOARD. Normally 1, but can be
153 larger when you have multiple screens on a single X display. */
154 int reference_count;
155
156 /* The text we're echoing in the modeline - partial key sequences,
157 usually. This is nil when not echoing. */
158 Lisp_Object KBOARD_INTERNAL_FIELD (echo_string);
159
160 /* This flag indicates that events were put into kbd_queue
161 while Emacs was running for some other KBOARD.
162 The flag means that, when Emacs goes into the any-kboard state again,
163 it should check this KBOARD to see if there is a complete command
164 waiting.
165
166 Note that the kbd_queue field can be non-nil even when
167 kbd_queue_has_data is 0. When we push back an incomplete
168 command, then this flag is 0, meaning we don't want to try
169 reading from this KBOARD again until more input arrives. */
170 char kbd_queue_has_data;
171
172 /* Nonzero means echo each character as typed. */
173 char immediate_echo;
174
175 /* If we have echoed a prompt string specified by the user,
176 this is its length in characters. Otherwise this is -1. */
177 char echo_after_prompt;
178 };
179
180 /* Temporarily used before a frame has been opened. */
181 extern KBOARD *initial_kboard;
182
183 /* In the single-kboard state, this is the kboard
184 from which input is accepted.
185
186 In the any-kboard state, this is the kboard from which we are
187 right now considering input. We can consider input from another
188 kboard, but doing so requires throwing to wrong_kboard_jmpbuf. */
189 extern KBOARD *current_kboard;
190
191 /* A list of all kboard objects, linked through next_kboard. */
192 extern KBOARD *all_kboards;
193 \f
194 /* Total number of times read_char has returned, modulo UINTMAX_MAX + 1. */
195 extern uintmax_t num_input_events;
196
197 /* Nonzero means polling for input is temporarily suppressed. */
198 extern int poll_suppress_count;
199
200 /* Vector holding the key sequence that invoked the current command.
201 It is reused for each command, and it may be longer than the current
202 sequence; this_command_key_count indicates how many elements
203 actually mean something. */
204 extern Lisp_Object this_command_keys;
205 extern ptrdiff_t this_command_key_count;
206
207 /* The frame in which the last input event occurred, or Qmacro if the
208 last event came from a macro. We use this to determine when to
209 generate switch-frame events. This may be cleared by functions
210 like Fselect_frame, to make sure that a switch-frame event is
211 generated by the next character. */
212 extern Lisp_Object internal_last_event_frame;
213 \f
214 extern Lisp_Object Qrecompute_lucid_menubar, Qactivate_menubar_hook;
215
216 /* This holds a Lisp vector that holds the properties of a single
217 menu item while decoding it in parse_menu_item.
218 Using a Lisp vector to hold this information while we decode it
219 takes care of protecting all the data from GC. */
220 extern Lisp_Object item_properties;
221
222 /* This describes the elements of item_properties.
223 The first element is not a property, it is a pointer to the item properties
224 that is saved for GC protection. */
225 #define ITEM_PROPERTY_ITEM 0
226 /* The item string. */
227 #define ITEM_PROPERTY_NAME 1
228 /* Start of initialize to nil */
229 /* The binding: nil, a command or a keymap. */
230 #define ITEM_PROPERTY_DEF 2
231 /* The keymap if the binding is a keymap, otherwise nil. */
232 #define ITEM_PROPERTY_MAP 3
233 /* Nil, :radio or :toggle. */
234 #define ITEM_PROPERTY_TYPE 4
235 /* Nil or a string describing an equivalent key binding. */
236 #define ITEM_PROPERTY_KEYEQ 5
237 /* Not nil if a selected toggle box or radio button, otherwise nil. */
238 #define ITEM_PROPERTY_SELECTED 6
239 /* Place for a help string. Not yet used. */
240 #define ITEM_PROPERTY_HELP 7
241 /* Start of initialize to t */
242 /* Last property. */
243 /* Not nil if item is enabled. */
244 #define ITEM_PROPERTY_ENABLE 8
245
246 /* This holds a Lisp vector that holds the results of decoding
247 the keymaps or alist-of-alists that specify a menu.
248
249 It describes the panes and items within the panes.
250
251 Each pane is described by 3 elements in the vector:
252 t, the pane name, the pane's prefix key.
253 Then follow the pane's items, with 5 elements per item:
254 the item string, the enable flag, the item's value,
255 the definition, and the equivalent keyboard key's description string.
256
257 In some cases, multiple levels of menus may be described.
258 A single vector slot containing nil indicates the start of a submenu.
259 A single vector slot containing lambda indicates the end of a submenu.
260 The submenu follows a menu item which is the way to reach the submenu.
261
262 A single vector slot containing quote indicates that the
263 following items should appear on the right of a dialog box.
264
265 Using a Lisp vector to hold this information while we decode it
266 takes care of protecting all the data from GC. */
267 extern Lisp_Object menu_items;
268
269 /* If non-nil, means that the global vars defined here are already in use.
270 Used to detect cases where we try to re-enter this non-reentrant code. */
271 #if defined USE_GTK || defined USE_MOTIF
272 extern Lisp_Object menu_items_inuse;
273 #endif
274
275 /* Number of slots currently allocated in menu_items. */
276 extern int menu_items_allocated;
277
278 /* This is the index in menu_items of the first empty slot. */
279 extern int menu_items_used;
280
281 /* The number of panes currently recorded in menu_items,
282 excluding those within submenus. */
283 extern int menu_items_n_panes;
284
285 #define MENU_ITEMS_PANE_NAME 1
286 #define MENU_ITEMS_PANE_PREFIX 2
287 #define MENU_ITEMS_PANE_LENGTH 3
288
289 enum menu_item_idx
290 {
291 MENU_ITEMS_ITEM_NAME = 0,
292 MENU_ITEMS_ITEM_ENABLE,
293 MENU_ITEMS_ITEM_VALUE,
294 MENU_ITEMS_ITEM_EQUIV_KEY,
295 MENU_ITEMS_ITEM_DEFINITION,
296 MENU_ITEMS_ITEM_TYPE,
297 MENU_ITEMS_ITEM_SELECTED,
298 MENU_ITEMS_ITEM_HELP,
299 MENU_ITEMS_ITEM_LENGTH
300 };
301
302 extern Lisp_Object unuse_menu_items (Lisp_Object dummy);
303
304 /* This is how to deal with multibyte text if HAVE_MULTILINGUAL_MENU
305 isn't defined. The use of HAVE_MULTILINGUAL_MENU could probably be
306 confined to an extended version of this with sections of code below
307 using it unconditionally. */
308 #ifndef HAVE_NTGUI
309 #if defined (USE_GTK) || defined (HAVE_NS)
310 # define ENCODE_MENU_STRING(str) ENCODE_UTF_8 (str)
311 #elif defined HAVE_X_I18N
312 #define ENCODE_MENU_STRING(str) ENCODE_SYSTEM (str)
313 #else
314 #define ENCODE_MENU_STRING(str) string_make_unibyte (str)
315 #endif /* USE_GTK */
316 #else /* HAVE_NTGUI */
317 #define ENCODE_MENU_STRING(str) (str)
318 #endif
319
320 #if defined (HAVE_NS) || defined (HAVE_NTGUI) || defined (USE_GTK)
321
322 /* Definitions copied from lwlib.h */
323
324 enum button_type
325 {
326 BUTTON_TYPE_NONE,
327 BUTTON_TYPE_TOGGLE,
328 BUTTON_TYPE_RADIO
329 };
330
331 /* This structure is based on the one in ../lwlib/lwlib.h, with unused portions
332 removed. No term uses these. */
333 typedef struct _widget_value
334 {
335 /* name of widget */
336 Lisp_Object lname;
337 const char* name;
338 /* value (meaning depend on widget type) */
339 const char* value;
340 /* keyboard equivalent. no implications for XtTranslations */
341 Lisp_Object lkey;
342 const char* key;
343 /* Help string or nil if none.
344 GC finds this string through the frame's menu_bar_vector
345 or through menu_items. */
346 Lisp_Object help;
347 /* true if enabled */
348 unsigned char enabled;
349 /* true if selected */
350 unsigned char selected;
351 /* The type of a button. */
352 enum button_type button_type;
353 #if defined (HAVE_NTGUI)
354 /* true if menu title */
355 unsigned char title;
356 #endif
357 /* Contents of the sub-widgets, also selected slot for checkbox */
358 struct _widget_value* contents;
359 /* data passed to callback */
360 void *call_data;
361 /* next one in the list */
362 struct _widget_value* next;
363 #ifdef USE_GTK
364 struct _widget_value *free_list;
365 #endif
366 } widget_value;
367
368 #endif /* HAVE_NS || HAVE_NTGUI */
369
370 \f
371 /* Macros for dealing with lispy events. */
372
373 /* True if EVENT has data fields describing it (i.e. a mouse click). */
374 #define EVENT_HAS_PARAMETERS(event) (CONSP (event))
375
376 /* Extract the head from an event.
377 This works on composite and simple events. */
378 #define EVENT_HEAD(event) \
379 (EVENT_HAS_PARAMETERS (event) ? XCAR (event) : (event))
380
381 /* Extract the starting and ending positions from a composite event. */
382 #define EVENT_START(event) (XCAR (XCDR (event)))
383 #define EVENT_END(event) (XCAR (XCDR (XCDR (event))))
384
385 /* Extract the click count from a multi-click event. */
386 #define EVENT_CLICK_COUNT(event) (Fnth (make_number (2), (event)))
387
388 /* Extract the fields of a position. */
389 #define POSN_WINDOW(posn) (XCAR (posn))
390 #define POSN_POSN(posn) (XCAR (XCDR (posn)))
391 #define POSN_SET_POSN(posn,x) (XSETCAR (XCDR (posn), (x)))
392 #define POSN_WINDOW_POSN(posn) (XCAR (XCDR (XCDR (posn))))
393 #define POSN_TIMESTAMP(posn) (XCAR (XCDR (XCDR (XCDR (posn)))))
394 #define POSN_SCROLLBAR_PART(posn) (Fnth (make_number (4), (posn)))
395
396 /* A cons (STRING . STRING-CHARPOS), or nil in mouse-click events.
397 It's a cons if the click is over a string in the mode line. */
398
399 #define POSN_STRING(posn) (Fnth (make_number (4), (posn)))
400
401 /* If POSN_STRING is nil, event refers to buffer location. */
402
403 #define POSN_INBUFFER_P(posn) (NILP (POSN_STRING (posn)))
404 #define POSN_BUFFER_POSN(posn) (Fnth (make_number (5), (posn)))
405
406 /* Some of the event heads. */
407 extern Lisp_Object Qswitch_frame;
408
409 /* Properties on event heads. */
410 extern Lisp_Object Qevent_kind;
411
412 /* The values of Qevent_kind properties. */
413 extern Lisp_Object Qmouse_click;
414
415 extern Lisp_Object Qhelp_echo;
416
417 /* Getting the kind of an event head. */
418 #define EVENT_HEAD_KIND(event_head) \
419 (Fget ((event_head), Qevent_kind))
420
421 /* Symbols to use for non-text mouse positions. */
422 extern Lisp_Object Qmode_line, Qvertical_line, Qheader_line;
423
424 /* True while doing kbd input. */
425 extern int waiting_for_input;
426
427 /* Address (if not 0) of EMACS_TIME to zero out if a SIGIO interrupt
428 happens. */
429 extern EMACS_TIME *input_available_clear_time;
430
431 #if defined HAVE_WINDOW_SYSTEM && !defined USE_GTK && !defined HAVE_NS
432 extern int ignore_mouse_drag_p;
433 #endif
434
435 /* The primary selection. */
436 extern Lisp_Object QPRIMARY;
437
438 /* Forward declaration for prototypes. */
439 struct input_event;
440
441 extern Lisp_Object parse_modifiers (Lisp_Object);
442 extern Lisp_Object reorder_modifiers (Lisp_Object);
443 extern Lisp_Object read_char (int, ptrdiff_t, Lisp_Object *, Lisp_Object,
444 int *, EMACS_TIME *);
445 extern int parse_solitary_modifier (Lisp_Object symbol);
446
447
448 /* This is like Vthis_command, except that commands never set it. */
449 extern Lisp_Object real_this_command;
450
451 /* Non-nil disable property on a command means
452 do not execute it; call disabled-command-function's value instead. */
453 extern Lisp_Object QCtoggle, QCradio;
454
455 /* An event header symbol HEAD may have a property named
456 Qevent_symbol_element_mask, which is of the form (BASE MODIFIERS);
457 BASE is the base, unmodified version of HEAD, and MODIFIERS is the
458 mask of modifiers applied to it. If present, this is used to help
459 speed up parse_modifiers. */
460 extern Lisp_Object Qevent_symbol_element_mask;
461
462 /* The timestamp of the last input event we received from the X server.
463 X Windows wants this for selection ownership. */
464 extern Time last_event_timestamp;
465
466 extern int quit_char;
467
468 extern int timers_run;
469
470 extern int menu_separator_name_p (const char *);
471 extern int parse_menu_item (Lisp_Object, int);
472
473 extern void init_kboard (KBOARD *);
474 extern void delete_kboard (KBOARD *);
475 extern void not_single_kboard_state (KBOARD *);
476 extern void push_kboard (struct kboard *);
477 extern void push_frame_kboard (struct frame *);
478 extern void pop_kboard (void);
479 extern void temporarily_switch_to_single_kboard (struct frame *);
480 extern void record_asynch_buffer_change (void);
481 extern void input_poll_signal (int);
482 extern void start_polling (void);
483 extern void stop_polling (void);
484 extern void set_poll_suppress_count (int);
485 extern void gobble_input (int);
486 extern int input_polling_used (void);
487 extern void clear_input_pending (void);
488 extern int requeued_events_pending_p (void);
489 extern void bind_polling_period (int);
490 extern int make_ctrl_char (int) ATTRIBUTE_CONST;
491 extern void stuff_buffered_input (Lisp_Object);
492 extern void clear_waiting_for_input (void);
493 extern void swallow_events (int);
494 extern int lucid_event_type_list_p (Lisp_Object);
495 extern void kbd_buffer_store_event (struct input_event *);
496 extern void kbd_buffer_store_event_hold (struct input_event *,
497 struct input_event *);
498 extern void kbd_buffer_unget_event (struct input_event *);
499 extern void poll_for_input_1 (void);
500 extern void show_help_echo (Lisp_Object, Lisp_Object, Lisp_Object,
501 Lisp_Object);
502 extern void gen_help_event (Lisp_Object, Lisp_Object, Lisp_Object,
503 Lisp_Object, ptrdiff_t);
504 extern void kbd_buffer_store_help_event (Lisp_Object, Lisp_Object);
505 extern Lisp_Object menu_item_eval_property (Lisp_Object);
506 extern int kbd_buffer_events_waiting (int);
507 extern void add_user_signal (int, const char *);
508
509 extern int tty_read_avail_input (struct terminal *, int,
510 struct input_event *);
511 extern EMACS_TIME timer_check (void);
512 extern void mark_kboards (void);
513
514 #ifdef WINDOWSNT
515 extern const char *const lispy_function_keys[];
516 #endif