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1 /************************************************************
2  * Copyright (c) 1993 by Silicon Graphics Computer Systems, Inc.
3  *
4  * Permission to use, copy, modify, and distribute this
5  * software and its documentation for any purpose and without
6  * fee is hereby granted, provided that the above copyright
7  * notice appear in all copies and that both that copyright
8  * notice and this permission notice appear in supporting
9  * documentation, and that the name of Silicon Graphics not be
10  * used in advertising or publicity pertaining to distribution
11  * of the software without specific prior written permission.
12  * Silicon Graphics makes no representation about the suitability
13  * of this software for any purpose. It is provided "as is"
14  * without any express or implied warranty.
15  *
16  * SILICON GRAPHICS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
17  * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
18  * AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
19  * GRAPHICS BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
20  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
21  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
22  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION  WITH
23  * THE USE OR PERFORMANCE OF THIS SOFTWARE.
24  *
25  ********************************************************/
26 
27 /*
28  * Copyright © 2012 Intel Corporation
29  * Copyright © 2012 Ran Benita <ran234@gmail.com>
30  *
31  * Permission is hereby granted, free of charge, to any person obtaining a
32  * copy of this software and associated documentation files (the "Software"),
33  * to deal in the Software without restriction, including without limitation
34  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
35  * and/or sell copies of the Software, and to permit persons to whom the
36  * Software is furnished to do so, subject to the following conditions:
37  *
38  * The above copyright notice and this permission notice (including the next
39  * paragraph) shall be included in all copies or substantial portions of the
40  * Software.
41  *
42  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
43  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
44  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
45  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
46  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
47  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
48  * DEALINGS IN THE SOFTWARE.
49  *
50  * Author: Daniel Stone <daniel@fooishbar.org>
51  */
52 
53 /*
54  * This is a bastardised version of xkbActions.c from the X server which
55  * does not support, for the moment:
56  *   - AccessX sticky/debounce/etc (will come later)
57  *   - pointer keys (may come later)
58  *   - key redirects (unlikely)
59  *   - messages (very unlikely)
60  */
61 
62 #include "keymap.h"
63 #include "keysym.h"
64 #include "utf8.h"
65 
66 struct xkb_filter {
67     union xkb_action action;
68     const struct xkb_key *key;
69     uint32_t priv;
70     bool (*func)(struct xkb_state *state,
71                  struct xkb_filter *filter,
72                  const struct xkb_key *key,
73                  enum xkb_key_direction direction);
74     int refcnt;
75 };
76 
77 struct state_components {
78     /* These may be negative, because of -1 group actions. */
79     int32_t base_group; /**< depressed */
80     int32_t latched_group;
81     int32_t locked_group;
82     xkb_layout_index_t group; /**< effective */
83 
84     xkb_mod_mask_t base_mods; /**< depressed */
85     xkb_mod_mask_t latched_mods;
86     xkb_mod_mask_t locked_mods;
87     xkb_mod_mask_t mods; /**< effective */
88 
89     xkb_led_mask_t leds;
90 };
91 
92 struct xkb_state {
93     /*
94      * Before updating the state, we keep a copy of just this struct. This
95      * allows us to report which components of the state have changed.
96      */
97     struct state_components components;
98 
99     /*
100      * At each event, we accumulate all the needed modifications to the base
101      * modifiers, and apply them at the end. These keep track of this state.
102      */
103     xkb_mod_mask_t set_mods;
104     xkb_mod_mask_t clear_mods;
105 
106     /*
107      * We mustn't clear a base modifier if there's another depressed key
108      * which affects it, e.g. given this sequence
109      * < Left Shift down, Right Shift down, Left Shift Up >
110      * the modifier should still be set. This keeps the count.
111      */
112     int16_t mod_key_count[XKB_MAX_MODS];
113 
114     int refcnt;
115     darray(struct xkb_filter) filters;
116     struct xkb_keymap *keymap;
117 };
118 
119 static const struct xkb_key_type_entry *
get_entry_for_key_state(struct xkb_state * state,const struct xkb_key * key,xkb_layout_index_t group)120 get_entry_for_key_state(struct xkb_state *state, const struct xkb_key *key,
121                         xkb_layout_index_t group)
122 {
123     const struct xkb_key_type *type = key->groups[group].type;
124     xkb_mod_mask_t active_mods = state->components.mods & type->mods.mask;
125 
126     for (unsigned i = 0; i < type->num_entries; i++) {
127         /*
128          * If the virtual modifiers are not bound to anything, we're
129          * supposed to skip the entry (xserver does this with cached
130          * entry->active field).
131          */
132         if (type->entries[i].mods.mods != 0 && type->entries[i].mods.mask == 0)
133             continue;
134 
135         if (type->entries[i].mods.mask == active_mods)
136             return &type->entries[i];
137     }
138 
139     return NULL;
140 }
141 
142 /**
143  * Returns the level to use for the given key and state, or
144  * XKB_LEVEL_INVALID.
145  */
146 XKB_EXPORT xkb_level_index_t
xkb_state_key_get_level(struct xkb_state * state,xkb_keycode_t kc,xkb_layout_index_t layout)147 xkb_state_key_get_level(struct xkb_state *state, xkb_keycode_t kc,
148                         xkb_layout_index_t layout)
149 {
150     const struct xkb_key *key = XkbKey(state->keymap, kc);
151     const struct xkb_key_type_entry *entry;
152 
153     if (!key || layout >= key->num_groups)
154         return XKB_LEVEL_INVALID;
155 
156     /* If we don't find an explicit match the default is 0. */
157     entry = get_entry_for_key_state(state, key, layout);
158     if (!entry)
159         return 0;
160 
161     return entry->level;
162 }
163 
164 xkb_layout_index_t
XkbWrapGroupIntoRange(int32_t group,xkb_layout_index_t num_groups,enum xkb_range_exceed_type out_of_range_group_action,xkb_layout_index_t out_of_range_group_number)165 XkbWrapGroupIntoRange(int32_t group,
166                       xkb_layout_index_t num_groups,
167                       enum xkb_range_exceed_type out_of_range_group_action,
168                       xkb_layout_index_t out_of_range_group_number)
169 {
170     if (num_groups == 0)
171         return XKB_LAYOUT_INVALID;
172 
173     if (group >= 0 && (xkb_layout_index_t) group < num_groups)
174         return group;
175 
176     switch (out_of_range_group_action) {
177     case RANGE_REDIRECT:
178         if (out_of_range_group_number >= num_groups)
179             return 0;
180         return out_of_range_group_number;
181 
182     case RANGE_SATURATE:
183         if (group < 0)
184             return 0;
185         else
186             return num_groups - 1;
187 
188     case RANGE_WRAP:
189     default:
190         /*
191          * C99 says a negative dividend in a modulo operation always
192          * gives a negative result.
193          */
194         if (group < 0)
195             return ((int) num_groups + (group % (int) num_groups));
196         else
197             return group % num_groups;
198     }
199 }
200 
201 /**
202  * Returns the layout to use for the given key and state, taking
203  * wrapping/clamping/etc into account, or XKB_LAYOUT_INVALID.
204  */
205 XKB_EXPORT xkb_layout_index_t
xkb_state_key_get_layout(struct xkb_state * state,xkb_keycode_t kc)206 xkb_state_key_get_layout(struct xkb_state *state, xkb_keycode_t kc)
207 {
208     const struct xkb_key *key = XkbKey(state->keymap, kc);
209 
210     if (!key)
211         return XKB_LAYOUT_INVALID;
212 
213     return XkbWrapGroupIntoRange(state->components.group, key->num_groups,
214                                  key->out_of_range_group_action,
215                                  key->out_of_range_group_number);
216 }
217 
218 static const union xkb_action fake = { .type = ACTION_TYPE_NONE };
219 
220 static const union xkb_action *
xkb_key_get_action(struct xkb_state * state,const struct xkb_key * key)221 xkb_key_get_action(struct xkb_state *state, const struct xkb_key *key)
222 {
223     xkb_layout_index_t layout;
224     xkb_level_index_t level;
225 
226     layout = xkb_state_key_get_layout(state, key->keycode);
227     if (layout == XKB_LAYOUT_INVALID)
228         return &fake;
229 
230     level = xkb_state_key_get_level(state, key->keycode, layout);
231     if (level == XKB_LEVEL_INVALID)
232         return &fake;
233 
234     return &key->groups[layout].levels[level].action;
235 }
236 
237 static struct xkb_filter *
xkb_filter_new(struct xkb_state * state)238 xkb_filter_new(struct xkb_state *state)
239 {
240     struct xkb_filter *filter = NULL, *iter;
241 
242     darray_foreach(iter, state->filters) {
243         if (iter->func)
244             continue;
245         filter = iter;
246         break;
247     }
248 
249     if (!filter) {
250         darray_resize0(state->filters, darray_size(state->filters) + 1);
251         filter = &darray_item(state->filters, darray_size(state->filters) -1);
252     }
253 
254     filter->refcnt = 1;
255     return filter;
256 }
257 
258 /***====================================================================***/
259 
260 static bool
xkb_filter_group_set_func(struct xkb_state * state,struct xkb_filter * filter,const struct xkb_key * key,enum xkb_key_direction direction)261 xkb_filter_group_set_func(struct xkb_state *state,
262                           struct xkb_filter *filter,
263                           const struct xkb_key *key,
264                           enum xkb_key_direction direction)
265 {
266     if (key != filter->key) {
267         filter->action.group.flags &= ~ACTION_LOCK_CLEAR;
268         return true;
269     }
270 
271     if (direction == XKB_KEY_DOWN) {
272         filter->refcnt++;
273         return false;
274     }
275     else if (--filter->refcnt > 0) {
276         return false;
277     }
278 
279     state->components.base_group = filter->priv;
280 
281     if (filter->action.group.flags & ACTION_LOCK_CLEAR)
282         state->components.locked_group = 0;
283 
284     filter->func = NULL;
285     return true;
286 }
287 
288 static void
xkb_filter_group_set_new(struct xkb_state * state,struct xkb_filter * filter)289 xkb_filter_group_set_new(struct xkb_state *state, struct xkb_filter *filter)
290 {
291     filter->priv = state->components.base_group;
292     if (filter->action.group.flags & ACTION_ABSOLUTE_SWITCH)
293         state->components.base_group = filter->action.group.group;
294     else
295         state->components.base_group += filter->action.group.group;
296 }
297 
298 static bool
xkb_filter_group_lock_func(struct xkb_state * state,struct xkb_filter * filter,const struct xkb_key * key,enum xkb_key_direction direction)299 xkb_filter_group_lock_func(struct xkb_state *state,
300                            struct xkb_filter *filter,
301                            const struct xkb_key *key,
302                            enum xkb_key_direction direction)
303 {
304     if (key != filter->key)
305         return true;
306 
307     if (direction == XKB_KEY_DOWN) {
308         filter->refcnt++;
309         return false;
310     }
311     if (--filter->refcnt > 0)
312         return false;
313 
314     filter->func = NULL;
315     return true;
316 }
317 
318 static void
xkb_filter_group_lock_new(struct xkb_state * state,struct xkb_filter * filter)319 xkb_filter_group_lock_new(struct xkb_state *state, struct xkb_filter *filter)
320 {
321     if (filter->action.group.flags & ACTION_ABSOLUTE_SWITCH)
322         state->components.locked_group = filter->action.group.group;
323     else
324         state->components.locked_group += filter->action.group.group;
325 }
326 
327 static bool
xkb_filter_mod_set_func(struct xkb_state * state,struct xkb_filter * filter,const struct xkb_key * key,enum xkb_key_direction direction)328 xkb_filter_mod_set_func(struct xkb_state *state,
329                         struct xkb_filter *filter,
330                         const struct xkb_key *key,
331                         enum xkb_key_direction direction)
332 {
333     if (key != filter->key) {
334         filter->action.mods.flags &= ~ACTION_LOCK_CLEAR;
335         return true;
336     }
337 
338     if (direction == XKB_KEY_DOWN) {
339         filter->refcnt++;
340         return false;
341     }
342     else if (--filter->refcnt > 0) {
343         return false;
344     }
345 
346     state->clear_mods = filter->action.mods.mods.mask;
347     if (filter->action.mods.flags & ACTION_LOCK_CLEAR)
348         state->components.locked_mods &= ~filter->action.mods.mods.mask;
349 
350     filter->func = NULL;
351     return true;
352 }
353 
354 static void
xkb_filter_mod_set_new(struct xkb_state * state,struct xkb_filter * filter)355 xkb_filter_mod_set_new(struct xkb_state *state, struct xkb_filter *filter)
356 {
357     state->set_mods = filter->action.mods.mods.mask;
358 }
359 
360 static bool
xkb_filter_mod_lock_func(struct xkb_state * state,struct xkb_filter * filter,const struct xkb_key * key,enum xkb_key_direction direction)361 xkb_filter_mod_lock_func(struct xkb_state *state,
362                          struct xkb_filter *filter,
363                          const struct xkb_key *key,
364                          enum xkb_key_direction direction)
365 {
366     if (key != filter->key)
367         return true;
368 
369     if (direction == XKB_KEY_DOWN) {
370         filter->refcnt++;
371         return false;
372     }
373     if (--filter->refcnt > 0)
374         return false;
375 
376     state->clear_mods |= filter->action.mods.mods.mask;
377     if (!(filter->action.mods.flags & ACTION_LOCK_NO_UNLOCK))
378         state->components.locked_mods &= ~filter->priv;
379 
380     filter->func = NULL;
381     return true;
382 }
383 
384 static void
xkb_filter_mod_lock_new(struct xkb_state * state,struct xkb_filter * filter)385 xkb_filter_mod_lock_new(struct xkb_state *state, struct xkb_filter *filter)
386 {
387     filter->priv = (state->components.locked_mods &
388                     filter->action.mods.mods.mask);
389     state->set_mods |= filter->action.mods.mods.mask;
390     if (!(filter->action.mods.flags & ACTION_LOCK_NO_LOCK))
391         state->components.locked_mods |= filter->action.mods.mods.mask;
392 }
393 
394 enum xkb_key_latch_state {
395     NO_LATCH,
396     LATCH_KEY_DOWN,
397     LATCH_PENDING,
398 };
399 
400 static bool
xkb_action_breaks_latch(const union xkb_action * action)401 xkb_action_breaks_latch(const union xkb_action *action)
402 {
403     switch (action->type) {
404     case ACTION_TYPE_NONE:
405     case ACTION_TYPE_PTR_BUTTON:
406     case ACTION_TYPE_PTR_LOCK:
407     case ACTION_TYPE_CTRL_SET:
408     case ACTION_TYPE_CTRL_LOCK:
409     case ACTION_TYPE_SWITCH_VT:
410     case ACTION_TYPE_TERMINATE:
411         return true;
412     default:
413         return false;
414     }
415 }
416 
417 static bool
xkb_filter_mod_latch_func(struct xkb_state * state,struct xkb_filter * filter,const struct xkb_key * key,enum xkb_key_direction direction)418 xkb_filter_mod_latch_func(struct xkb_state *state,
419                           struct xkb_filter *filter,
420                           const struct xkb_key *key,
421                           enum xkb_key_direction direction)
422 {
423     enum xkb_key_latch_state latch = filter->priv;
424 
425     if (direction == XKB_KEY_DOWN && latch == LATCH_PENDING) {
426         /* If this is a new keypress and we're awaiting our single latched
427          * keypress, then either break the latch if any random key is pressed,
428          * or promote it to a lock or plain base set if it's the same
429          * modifier. */
430         const union xkb_action *action = xkb_key_get_action(state, key);
431         if (action->type == ACTION_TYPE_MOD_LATCH &&
432             action->mods.flags == filter->action.mods.flags &&
433             action->mods.mods.mask == filter->action.mods.mods.mask) {
434             filter->action = *action;
435             if (filter->action.mods.flags & ACTION_LATCH_TO_LOCK) {
436                 filter->action.type = ACTION_TYPE_MOD_LOCK;
437                 filter->func = xkb_filter_mod_lock_func;
438                 state->components.locked_mods |= filter->action.mods.mods.mask;
439             }
440             else {
441                 filter->action.type = ACTION_TYPE_MOD_SET;
442                 filter->func = xkb_filter_mod_set_func;
443                 state->set_mods = filter->action.mods.mods.mask;
444             }
445             filter->key = key;
446             state->components.latched_mods &= ~filter->action.mods.mods.mask;
447             /* XXX beep beep! */
448             return false;
449         }
450         else if (xkb_action_breaks_latch(action)) {
451             /* XXX: This may be totally broken, we might need to break the
452              *      latch in the next run after this press? */
453             state->components.latched_mods &= ~filter->action.mods.mods.mask;
454             filter->func = NULL;
455             return true;
456         }
457     }
458     else if (direction == XKB_KEY_UP && key == filter->key) {
459         /* Our key got released.  If we've set it to clear locks, and we
460          * currently have the same modifiers locked, then release them and
461          * don't actually latch.  Else we've actually hit the latching
462          * stage, so set PENDING and move our modifier from base to
463          * latched. */
464         if (latch == NO_LATCH ||
465             ((filter->action.mods.flags & ACTION_LOCK_CLEAR) &&
466              (state->components.locked_mods & filter->action.mods.mods.mask) ==
467              filter->action.mods.mods.mask)) {
468             /* XXX: We might be a bit overenthusiastic about clearing
469              *      mods other filters have set here? */
470             if (latch == LATCH_PENDING)
471                 state->components.latched_mods &=
472                     ~filter->action.mods.mods.mask;
473             else
474                 state->clear_mods = filter->action.mods.mods.mask;
475             state->components.locked_mods &= ~filter->action.mods.mods.mask;
476             filter->func = NULL;
477         }
478         else {
479             latch = LATCH_PENDING;
480             state->clear_mods = filter->action.mods.mods.mask;
481             state->components.latched_mods |= filter->action.mods.mods.mask;
482             /* XXX beep beep! */
483         }
484     }
485     else if (direction == XKB_KEY_DOWN && latch == LATCH_KEY_DOWN) {
486         /* Someone's pressed another key while we've still got the latching
487          * key held down, so keep the base modifier state active (from
488          * xkb_filter_mod_latch_new), but don't trip the latch, just clear
489          * it as soon as the modifier gets released. */
490         latch = NO_LATCH;
491     }
492 
493     filter->priv = latch;
494 
495     return true;
496 }
497 
498 static void
xkb_filter_mod_latch_new(struct xkb_state * state,struct xkb_filter * filter)499 xkb_filter_mod_latch_new(struct xkb_state *state, struct xkb_filter *filter)
500 {
501     filter->priv = LATCH_KEY_DOWN;
502     state->set_mods = filter->action.mods.mods.mask;
503 }
504 
505 static const struct {
506     void (*new)(struct xkb_state *state, struct xkb_filter *filter);
507     bool (*func)(struct xkb_state *state, struct xkb_filter *filter,
508                  const struct xkb_key *key, enum xkb_key_direction direction);
509 } filter_action_funcs[_ACTION_TYPE_NUM_ENTRIES] = {
510     [ACTION_TYPE_MOD_SET]    = { xkb_filter_mod_set_new,
511                                  xkb_filter_mod_set_func },
512     [ACTION_TYPE_MOD_LATCH]  = { xkb_filter_mod_latch_new,
513                                  xkb_filter_mod_latch_func },
514     [ACTION_TYPE_MOD_LOCK]   = { xkb_filter_mod_lock_new,
515                                  xkb_filter_mod_lock_func },
516     [ACTION_TYPE_GROUP_SET]  = { xkb_filter_group_set_new,
517                                  xkb_filter_group_set_func },
518     [ACTION_TYPE_GROUP_LOCK] = { xkb_filter_group_lock_new,
519                                  xkb_filter_group_lock_func },
520 };
521 
522 /**
523  * Applies any relevant filters to the key, first from the list of filters
524  * that are currently active, then if no filter has claimed the key, possibly
525  * apply a new filter from the key action.
526  */
527 static void
xkb_filter_apply_all(struct xkb_state * state,const struct xkb_key * key,enum xkb_key_direction direction)528 xkb_filter_apply_all(struct xkb_state *state,
529                      const struct xkb_key *key,
530                      enum xkb_key_direction direction)
531 {
532     struct xkb_filter *filter;
533     const union xkb_action *action;
534     bool send = true;
535 
536     /* First run through all the currently active filters and see if any of
537      * them have claimed this event. */
538     darray_foreach(filter, state->filters) {
539         if (!filter->func)
540             continue;
541         send = filter->func(state, filter, key, direction) && send;
542     }
543 
544     if (!send || direction == XKB_KEY_UP)
545         return;
546 
547     action = xkb_key_get_action(state, key);
548 
549     /*
550      * It's possible for the keymap to set action->type explicitly, like so:
551      *     interpret XF86_Next_VMode {
552      *         action = Private(type=0x86, data="+VMode");
553      *     };
554      * We don't handle those.
555      */
556     if (action->type >= _ACTION_TYPE_NUM_ENTRIES)
557         return;
558 
559     if (!filter_action_funcs[action->type].new)
560         return;
561 
562     filter = xkb_filter_new(state);
563     if (!filter)
564         return; /* WSGO */
565 
566     filter->key = key;
567     filter->func = filter_action_funcs[action->type].func;
568     filter->action = *action;
569     filter_action_funcs[action->type].new(state, filter);
570 }
571 
572 XKB_EXPORT struct xkb_state *
xkb_state_new(struct xkb_keymap * keymap)573 xkb_state_new(struct xkb_keymap *keymap)
574 {
575     struct xkb_state *ret;
576 
577     ret = calloc(sizeof(*ret), 1);
578     if (!ret)
579         return NULL;
580 
581     ret->refcnt = 1;
582     ret->keymap = xkb_keymap_ref(keymap);
583 
584     return ret;
585 }
586 
587 XKB_EXPORT struct xkb_state *
xkb_state_ref(struct xkb_state * state)588 xkb_state_ref(struct xkb_state *state)
589 {
590     state->refcnt++;
591     return state;
592 }
593 
594 XKB_EXPORT void
xkb_state_unref(struct xkb_state * state)595 xkb_state_unref(struct xkb_state *state)
596 {
597     if (!state || --state->refcnt > 0)
598         return;
599 
600     xkb_keymap_unref(state->keymap);
601     darray_free(state->filters);
602     free(state);
603 }
604 
605 XKB_EXPORT struct xkb_keymap *
xkb_state_get_keymap(struct xkb_state * state)606 xkb_state_get_keymap(struct xkb_state *state)
607 {
608     return state->keymap;
609 }
610 
611 /**
612  * Update the LED state to match the rest of the xkb_state.
613  */
614 static void
xkb_state_led_update_all(struct xkb_state * state)615 xkb_state_led_update_all(struct xkb_state *state)
616 {
617     xkb_led_index_t idx;
618     const struct xkb_led *led;
619 
620     state->components.leds = 0;
621 
622     xkb_leds_enumerate(idx, led, state->keymap) {
623         xkb_mod_mask_t mod_mask = 0;
624         xkb_layout_mask_t group_mask = 0;
625 
626         if (led->which_mods != 0 && led->mods.mask != 0) {
627             if (led->which_mods & XKB_STATE_MODS_EFFECTIVE)
628                 mod_mask |= state->components.mods;
629             if (led->which_mods & XKB_STATE_MODS_DEPRESSED)
630                 mod_mask |= state->components.base_mods;
631             if (led->which_mods & XKB_STATE_MODS_LATCHED)
632                 mod_mask |= state->components.latched_mods;
633             if (led->which_mods & XKB_STATE_MODS_LOCKED)
634                 mod_mask |= state->components.locked_mods;
635 
636             if (led->mods.mask & mod_mask) {
637                 state->components.leds |= (1u << idx);
638                 continue;
639             }
640         }
641 
642         if (led->which_groups != 0 && led->groups != 0) {
643             if (led->which_groups & XKB_STATE_LAYOUT_EFFECTIVE)
644                 group_mask |= (1u << state->components.group);
645             if (led->which_groups & XKB_STATE_LAYOUT_DEPRESSED)
646                 group_mask |= (1u << state->components.base_group);
647             if (led->which_groups & XKB_STATE_LAYOUT_LATCHED)
648                 group_mask |= (1u << state->components.latched_group);
649             if (led->which_groups & XKB_STATE_LAYOUT_LOCKED)
650                 group_mask |= (1u << state->components.locked_group);
651 
652             if (led->groups & group_mask) {
653                 state->components.leds |= (1u << idx);
654                 continue;
655             }
656         }
657 
658         if (led->ctrls & state->keymap->enabled_ctrls) {
659             state->components.leds |= (1u << idx);
660             continue;
661         }
662     }
663 }
664 
665 /**
666  * Calculates the derived state (effective mods/group and LEDs) from an
667  * up-to-date xkb_state.
668  */
669 static void
xkb_state_update_derived(struct xkb_state * state)670 xkb_state_update_derived(struct xkb_state *state)
671 {
672     xkb_layout_index_t wrapped;
673 
674     state->components.mods = (state->components.base_mods |
675                               state->components.latched_mods |
676                               state->components.locked_mods);
677 
678     /* TODO: Use groups_wrap control instead of always RANGE_WRAP. */
679 
680     wrapped = XkbWrapGroupIntoRange(state->components.locked_group,
681                                     state->keymap->num_groups,
682                                     RANGE_WRAP, 0);
683     state->components.locked_group =
684         (wrapped == XKB_LAYOUT_INVALID ? 0 : wrapped);
685 
686     wrapped = XkbWrapGroupIntoRange(state->components.base_group +
687                                     state->components.latched_group +
688                                     state->components.locked_group,
689                                     state->keymap->num_groups,
690                                     RANGE_WRAP, 0);
691     state->components.group =
692         (wrapped == XKB_LAYOUT_INVALID ? 0 : wrapped);
693 
694     xkb_state_led_update_all(state);
695 }
696 
697 static enum xkb_state_component
get_state_component_changes(const struct state_components * a,const struct state_components * b)698 get_state_component_changes(const struct state_components *a,
699                             const struct state_components *b)
700 {
701     xkb_mod_mask_t mask = 0;
702 
703     if (a->group != b->group)
704         mask |= XKB_STATE_LAYOUT_EFFECTIVE;
705     if (a->base_group != b->base_group)
706         mask |= XKB_STATE_LAYOUT_DEPRESSED;
707     if (a->latched_group != b->latched_group)
708         mask |= XKB_STATE_LAYOUT_LATCHED;
709     if (a->locked_group != b->locked_group)
710         mask |= XKB_STATE_LAYOUT_LOCKED;
711     if (a->mods != b->mods)
712         mask |= XKB_STATE_MODS_EFFECTIVE;
713     if (a->base_mods != b->base_mods)
714         mask |= XKB_STATE_MODS_DEPRESSED;
715     if (a->latched_mods != b->latched_mods)
716         mask |= XKB_STATE_MODS_LATCHED;
717     if (a->locked_mods != b->locked_mods)
718         mask |= XKB_STATE_MODS_LOCKED;
719     if (a->leds != b->leds)
720         mask |= XKB_STATE_LEDS;
721 
722     return mask;
723 }
724 
725 /**
726  * Given a particular key event, updates the state structure to reflect the
727  * new modifiers.
728  */
729 XKB_EXPORT enum xkb_state_component
xkb_state_update_key(struct xkb_state * state,xkb_keycode_t kc,enum xkb_key_direction direction)730 xkb_state_update_key(struct xkb_state *state, xkb_keycode_t kc,
731                      enum xkb_key_direction direction)
732 {
733     xkb_mod_index_t i;
734     xkb_mod_mask_t bit;
735     struct state_components prev_components;
736     const struct xkb_key *key = XkbKey(state->keymap, kc);
737 
738     if (!key)
739         return 0;
740 
741     prev_components = state->components;
742 
743     state->set_mods = 0;
744     state->clear_mods = 0;
745 
746     xkb_filter_apply_all(state, key, direction);
747 
748     for (i = 0, bit = 1; state->set_mods; i++, bit <<= 1) {
749         if (state->set_mods & bit) {
750             state->mod_key_count[i]++;
751             state->components.base_mods |= bit;
752             state->set_mods &= ~bit;
753         }
754     }
755 
756     for (i = 0, bit = 1; state->clear_mods; i++, bit <<= 1) {
757         if (state->clear_mods & bit) {
758             state->mod_key_count[i]--;
759             if (state->mod_key_count[i] <= 0) {
760                 state->components.base_mods &= ~bit;
761                 state->mod_key_count[i] = 0;
762             }
763             state->clear_mods &= ~bit;
764         }
765     }
766 
767     xkb_state_update_derived(state);
768 
769     return get_state_component_changes(&prev_components, &state->components);
770 }
771 
772 /**
773  * Updates the state from a set of explicit masks as gained from
774  * xkb_state_serialize_mods and xkb_state_serialize_groups.  As noted in the
775  * documentation for these functions in xkbcommon.h, this round-trip is
776  * lossy, and should only be used to update a slave state mirroring the
777  * master, e.g. in a client/server window system.
778  */
779 XKB_EXPORT enum xkb_state_component
xkb_state_update_mask(struct xkb_state * state,xkb_mod_mask_t base_mods,xkb_mod_mask_t latched_mods,xkb_mod_mask_t locked_mods,xkb_layout_index_t base_group,xkb_layout_index_t latched_group,xkb_layout_index_t locked_group)780 xkb_state_update_mask(struct xkb_state *state,
781                       xkb_mod_mask_t base_mods,
782                       xkb_mod_mask_t latched_mods,
783                       xkb_mod_mask_t locked_mods,
784                       xkb_layout_index_t base_group,
785                       xkb_layout_index_t latched_group,
786                       xkb_layout_index_t locked_group)
787 {
788     struct state_components prev_components;
789     xkb_mod_mask_t mask;
790 
791     prev_components = state->components;
792 
793     /* Only include modifiers which exist in the keymap. */
794     mask = (xkb_mod_mask_t) ((1ull << xkb_keymap_num_mods(state->keymap)) - 1u);
795 
796     state->components.base_mods = base_mods & mask;
797     state->components.latched_mods = latched_mods & mask;
798     state->components.locked_mods = locked_mods & mask;
799 
800     /* Make sure the mods are fully resolved - since we get arbitrary
801      * input, they might not be.
802      *
803      * It might seem more reasonable to do this only for components.mods
804      * in xkb_state_update_derived(), rather than for each component
805      * seperately.  That would allow to distinguish between "really"
806      * depressed mods (would be in MODS_DEPRESSED) and indirectly
807      * depressed to to a mapping (would only be in MODS_EFFECTIVE).
808      * However, the traditional behavior of xkb_state_update_key() is that
809      * if a vmod is depressed, its mappings are depressed with it; so we're
810      * expected to do the same here.  Also, LEDs (usually) look if a real
811      * mod is locked, not just effective; otherwise it won't be lit.
812      *
813      * We OR here because mod_mask_get_effective() drops vmods. */
814     state->components.base_mods |=
815         mod_mask_get_effective(state->keymap, state->components.base_mods);
816     state->components.latched_mods |=
817         mod_mask_get_effective(state->keymap, state->components.latched_mods);
818     state->components.locked_mods |=
819         mod_mask_get_effective(state->keymap, state->components.locked_mods);
820 
821     state->components.base_group = base_group;
822     state->components.latched_group = latched_group;
823     state->components.locked_group = locked_group;
824 
825     xkb_state_update_derived(state);
826 
827     return get_state_component_changes(&prev_components, &state->components);
828 }
829 
830 /**
831  * Provides the symbols to use for the given key and state.  Returns the
832  * number of symbols pointed to in syms_out.
833  */
834 XKB_EXPORT int
xkb_state_key_get_syms(struct xkb_state * state,xkb_keycode_t kc,const xkb_keysym_t ** syms_out)835 xkb_state_key_get_syms(struct xkb_state *state, xkb_keycode_t kc,
836                        const xkb_keysym_t **syms_out)
837 {
838     xkb_layout_index_t layout;
839     xkb_level_index_t level;
840 
841     layout = xkb_state_key_get_layout(state, kc);
842     if (layout == XKB_LAYOUT_INVALID)
843         goto err;
844 
845     level = xkb_state_key_get_level(state, kc, layout);
846     if (level == XKB_LEVEL_INVALID)
847         goto err;
848 
849     return xkb_keymap_key_get_syms_by_level(state->keymap, kc, layout, level,
850                                             syms_out);
851 
852 err:
853     *syms_out = NULL;
854     return 0;
855 }
856 
857 /*
858  * http://www.x.org/releases/current/doc/kbproto/xkbproto.html#Interpreting_the_Lock_Modifier
859  */
860 static bool
should_do_caps_transformation(struct xkb_state * state,xkb_keycode_t kc)861 should_do_caps_transformation(struct xkb_state *state, xkb_keycode_t kc)
862 {
863     xkb_mod_index_t caps =
864         xkb_keymap_mod_get_index(state->keymap, XKB_MOD_NAME_CAPS);
865 
866     return
867         xkb_state_mod_index_is_active(state, caps, XKB_STATE_MODS_EFFECTIVE) > 0 &&
868         xkb_state_mod_index_is_consumed(state, kc, caps) == 0;
869 }
870 
871 /*
872  * http://www.x.org/releases/current/doc/kbproto/xkbproto.html#Interpreting_the_Control_Modifier
873  */
874 static bool
should_do_ctrl_transformation(struct xkb_state * state,xkb_keycode_t kc)875 should_do_ctrl_transformation(struct xkb_state *state, xkb_keycode_t kc)
876 {
877     xkb_mod_index_t ctrl =
878         xkb_keymap_mod_get_index(state->keymap, XKB_MOD_NAME_CTRL);
879 
880     return
881         xkb_state_mod_index_is_active(state, ctrl, XKB_STATE_MODS_EFFECTIVE) > 0 &&
882         xkb_state_mod_index_is_consumed(state, kc, ctrl) == 0;
883 }
884 
885 /* Verbatim from libX11:src/xkb/XKBBind.c */
886 static char
XkbToControl(char ch)887 XkbToControl(char ch)
888 {
889     char c = ch;
890 
891     if ((c >= '@' && c < '\177') || c == ' ')
892         c &= 0x1F;
893     else if (c == '2')
894         c = '\000';
895     else if (c >= '3' && c <= '7')
896         c -= ('3' - '\033');
897     else if (c == '8')
898         c = '\177';
899     else if (c == '/')
900         c = '_' & 0x1F;
901     return c;
902 }
903 
904 /**
905  * Provides either exactly one symbol, or XKB_KEY_NoSymbol.
906  */
907 XKB_EXPORT xkb_keysym_t
xkb_state_key_get_one_sym(struct xkb_state * state,xkb_keycode_t kc)908 xkb_state_key_get_one_sym(struct xkb_state *state, xkb_keycode_t kc)
909 {
910     const xkb_keysym_t *syms;
911     xkb_keysym_t sym;
912     int num_syms;
913 
914     num_syms = xkb_state_key_get_syms(state, kc, &syms);
915     if (num_syms != 1)
916         return XKB_KEY_NoSymbol;
917 
918     sym = syms[0];
919 
920     if (should_do_caps_transformation(state, kc))
921         sym = xkb_keysym_to_upper(sym);
922 
923     return sym;
924 }
925 
926 /*
927  * The caps and ctrl transformations require some special handling,
928  * so we cannot simply use xkb_state_get_one_sym() for them.
929  * In particular, if Control is set, we must try very hard to find
930  * some layout in which the keysym is ASCII and thus can be (maybe)
931  * converted to a control character. libX11 allows to disable this
932  * behavior with the XkbLC_ControlFallback (see XkbSetXlibControls(3)),
933  * but it is enabled by default, yippee.
934  */
935 static xkb_keysym_t
get_one_sym_for_string(struct xkb_state * state,xkb_keycode_t kc)936 get_one_sym_for_string(struct xkb_state *state, xkb_keycode_t kc)
937 {
938     xkb_level_index_t level;
939     xkb_layout_index_t layout, num_layouts;
940     const xkb_keysym_t *syms;
941     int nsyms;
942     xkb_keysym_t sym;
943 
944     layout = xkb_state_key_get_layout(state, kc);
945     num_layouts = xkb_keymap_num_layouts_for_key(state->keymap, kc);
946     level = xkb_state_key_get_level(state, kc, layout);
947     if (layout == XKB_LAYOUT_INVALID || num_layouts == 0 ||
948         level == XKB_LEVEL_INVALID)
949         return XKB_KEY_NoSymbol;
950 
951     nsyms = xkb_keymap_key_get_syms_by_level(state->keymap, kc,
952                                              layout, level, &syms);
953     if (nsyms != 1)
954         return XKB_KEY_NoSymbol;
955     sym = syms[0];
956 
957     if (should_do_ctrl_transformation(state, kc) && sym > 127u) {
958         for (xkb_layout_index_t i = 0; i < num_layouts; i++) {
959             level = xkb_state_key_get_level(state, kc, i);
960             if (level == XKB_LEVEL_INVALID)
961                 continue;
962 
963             nsyms = xkb_keymap_key_get_syms_by_level(state->keymap, kc,
964                                                      i, level, &syms);
965             if (nsyms == 1 && syms[0] <= 127u) {
966                 sym = syms[0];
967                 break;
968             }
969         }
970     }
971 
972     if (should_do_caps_transformation(state, kc)) {
973         sym = xkb_keysym_to_upper(sym);
974     }
975 
976     return sym;
977 }
978 
979 XKB_EXPORT int
xkb_state_key_get_utf8(struct xkb_state * state,xkb_keycode_t kc,char * buffer,size_t size)980 xkb_state_key_get_utf8(struct xkb_state *state, xkb_keycode_t kc,
981                        char *buffer, size_t size)
982 {
983     xkb_keysym_t sym;
984     const xkb_keysym_t *syms;
985     int nsyms;
986     int offset;
987     char tmp[7];
988 
989     sym = get_one_sym_for_string(state, kc);
990     if (sym != XKB_KEY_NoSymbol) {
991         nsyms = 1; syms = &sym;
992     }
993     else {
994         nsyms = xkb_state_key_get_syms(state, kc, &syms);
995     }
996 
997     /* Make sure not to truncate in the middle of a UTF-8 sequence. */
998     offset = 0;
999     for (int i = 0; i < nsyms; i++) {
1000         int ret = xkb_keysym_to_utf8(syms[i], tmp, sizeof(tmp));
1001         if (ret <= 0)
1002             goto err_bad;
1003 
1004         ret--;
1005         if ((size_t) (offset + ret) <= size)
1006             memcpy(buffer + offset, tmp, ret);
1007         offset += ret;
1008     }
1009 
1010     if ((size_t) offset >= size)
1011         goto err_trunc;
1012     buffer[offset] = '\0';
1013 
1014     if (!is_valid_utf8(buffer, offset))
1015         goto err_bad;
1016 
1017     if (offset == 1 && (unsigned int) buffer[0] <= 127u &&
1018         should_do_ctrl_transformation(state, kc))
1019         buffer[0] = XkbToControl(buffer[0]);
1020 
1021     return offset;
1022 
1023 err_trunc:
1024     if (size > 0)
1025         buffer[size - 1] = '\0';
1026     return offset;
1027 
1028 err_bad:
1029     if (size > 0)
1030         buffer[0] = '\0';
1031     return 0;
1032 }
1033 
1034 XKB_EXPORT uint32_t
xkb_state_key_get_utf32(struct xkb_state * state,xkb_keycode_t kc)1035 xkb_state_key_get_utf32(struct xkb_state *state, xkb_keycode_t kc)
1036 {
1037     xkb_keysym_t sym;
1038     uint32_t cp;
1039 
1040     sym = get_one_sym_for_string(state, kc);
1041     cp = xkb_keysym_to_utf32(sym);
1042 
1043     if (cp <= 127u && should_do_ctrl_transformation(state, kc))
1044         cp = (uint32_t) XkbToControl((char) cp);
1045 
1046     return cp;
1047 }
1048 
1049 /**
1050  * Serialises the requested modifier state into an xkb_mod_mask_t, with all
1051  * the same disclaimers as in xkb_state_update_mask.
1052  */
1053 XKB_EXPORT xkb_mod_mask_t
xkb_state_serialize_mods(struct xkb_state * state,enum xkb_state_component type)1054 xkb_state_serialize_mods(struct xkb_state *state,
1055                          enum xkb_state_component type)
1056 {
1057     xkb_mod_mask_t ret = 0;
1058 
1059     if (type & XKB_STATE_MODS_EFFECTIVE)
1060         return state->components.mods;
1061 
1062     if (type & XKB_STATE_MODS_DEPRESSED)
1063         ret |= state->components.base_mods;
1064     if (type & XKB_STATE_MODS_LATCHED)
1065         ret |= state->components.latched_mods;
1066     if (type & XKB_STATE_MODS_LOCKED)
1067         ret |= state->components.locked_mods;
1068 
1069     return ret;
1070 }
1071 
1072 /**
1073  * Serialises the requested group state, with all the same disclaimers as
1074  * in xkb_state_update_mask.
1075  */
1076 XKB_EXPORT xkb_layout_index_t
xkb_state_serialize_layout(struct xkb_state * state,enum xkb_state_component type)1077 xkb_state_serialize_layout(struct xkb_state *state,
1078                            enum xkb_state_component type)
1079 {
1080     xkb_layout_index_t ret = 0;
1081 
1082     if (type & XKB_STATE_LAYOUT_EFFECTIVE)
1083         return state->components.group;
1084 
1085     if (type & XKB_STATE_LAYOUT_DEPRESSED)
1086         ret += state->components.base_group;
1087     if (type & XKB_STATE_LAYOUT_LATCHED)
1088         ret += state->components.latched_group;
1089     if (type & XKB_STATE_LAYOUT_LOCKED)
1090         ret += state->components.locked_group;
1091 
1092     return ret;
1093 }
1094 
1095 /**
1096  * Gets a modifier mask and returns the resolved effective mask; this
1097  * is needed because some modifiers can also map to other modifiers, e.g.
1098  * the "NumLock" modifier usually also sets the "Mod2" modifier.
1099  */
1100 xkb_mod_mask_t
mod_mask_get_effective(struct xkb_keymap * keymap,xkb_mod_mask_t mods)1101 mod_mask_get_effective(struct xkb_keymap *keymap, xkb_mod_mask_t mods)
1102 {
1103     const struct xkb_mod *mod;
1104     xkb_mod_index_t i;
1105     xkb_mod_mask_t mask;
1106 
1107     /* The effective mask is only real mods for now. */
1108     mask = mods & MOD_REAL_MASK_ALL;
1109 
1110     xkb_mods_enumerate(i, mod, &keymap->mods)
1111         if (mods & (1u << i))
1112             mask |= mod->mapping;
1113 
1114     return mask;
1115 }
1116 
1117 /**
1118  * Returns 1 if the given modifier is active with the specified type(s), 0 if
1119  * not, or -1 if the modifier is invalid.
1120  */
1121 XKB_EXPORT int
xkb_state_mod_index_is_active(struct xkb_state * state,xkb_mod_index_t idx,enum xkb_state_component type)1122 xkb_state_mod_index_is_active(struct xkb_state *state,
1123                               xkb_mod_index_t idx,
1124                               enum xkb_state_component type)
1125 {
1126     if (idx >= xkb_keymap_num_mods(state->keymap))
1127         return -1;
1128 
1129     return !!(xkb_state_serialize_mods(state, type) & (1u << idx));
1130 }
1131 
1132 /**
1133  * Helper function for xkb_state_mod_indices_are_active and
1134  * xkb_state_mod_names_are_active.
1135  */
1136 static int
match_mod_masks(struct xkb_state * state,enum xkb_state_component type,enum xkb_state_match match,xkb_mod_mask_t wanted)1137 match_mod_masks(struct xkb_state *state,
1138                 enum xkb_state_component type,
1139                 enum xkb_state_match match,
1140                 xkb_mod_mask_t wanted)
1141 {
1142     xkb_mod_mask_t active = xkb_state_serialize_mods(state, type);
1143 
1144     if (!(match & XKB_STATE_MATCH_NON_EXCLUSIVE) && (active & ~wanted))
1145         return 0;
1146 
1147     if (match & XKB_STATE_MATCH_ANY)
1148         return !!(active & wanted);
1149     else
1150         return (active & wanted) == wanted;
1151 
1152     return 0;
1153 }
1154 
1155 /**
1156  * Returns 1 if the modifiers are active with the specified type(s), 0 if
1157  * not, or -1 if any of the modifiers are invalid.
1158  */
1159 XKB_EXPORT int
xkb_state_mod_indices_are_active(struct xkb_state * state,enum xkb_state_component type,enum xkb_state_match match,...)1160 xkb_state_mod_indices_are_active(struct xkb_state *state,
1161                                  enum xkb_state_component type,
1162                                  enum xkb_state_match match,
1163                                  ...)
1164 {
1165     va_list ap;
1166     xkb_mod_index_t idx = 0;
1167     xkb_mod_mask_t wanted = 0;
1168     int ret = 0;
1169     xkb_mod_index_t num_mods = xkb_keymap_num_mods(state->keymap);
1170 
1171     va_start(ap, match);
1172     while (1) {
1173         idx = va_arg(ap, xkb_mod_index_t);
1174         if (idx == XKB_MOD_INVALID)
1175             break;
1176         if (idx >= num_mods) {
1177             ret = -1;
1178             break;
1179         }
1180         wanted |= (1u << idx);
1181     }
1182     va_end(ap);
1183 
1184     if (ret == -1)
1185         return ret;
1186 
1187     return match_mod_masks(state, type, match, wanted);
1188 }
1189 
1190 /**
1191  * Returns 1 if the given modifier is active with the specified type(s), 0 if
1192  * not, or -1 if the modifier is invalid.
1193  */
1194 XKB_EXPORT int
xkb_state_mod_name_is_active(struct xkb_state * state,const char * name,enum xkb_state_component type)1195 xkb_state_mod_name_is_active(struct xkb_state *state, const char *name,
1196                              enum xkb_state_component type)
1197 {
1198     xkb_mod_index_t idx = xkb_keymap_mod_get_index(state->keymap, name);
1199 
1200     if (idx == XKB_MOD_INVALID)
1201         return -1;
1202 
1203     return xkb_state_mod_index_is_active(state, idx, type);
1204 }
1205 
1206 /**
1207  * Returns 1 if the modifiers are active with the specified type(s), 0 if
1208  * not, or -1 if any of the modifiers are invalid.
1209  */
1210 XKB_EXPORT ATTR_NULL_SENTINEL int
xkb_state_mod_names_are_active(struct xkb_state * state,enum xkb_state_component type,enum xkb_state_match match,...)1211 xkb_state_mod_names_are_active(struct xkb_state *state,
1212                                enum xkb_state_component type,
1213                                enum xkb_state_match match,
1214                                ...)
1215 {
1216     va_list ap;
1217     xkb_mod_index_t idx = 0;
1218     xkb_mod_mask_t wanted = 0;
1219     int ret = 0;
1220 
1221     va_start(ap, match);
1222     while (1) {
1223         const char *str = va_arg(ap, const char *);
1224         if (str == NULL)
1225             break;
1226         idx = xkb_keymap_mod_get_index(state->keymap, str);
1227         if (idx == XKB_MOD_INVALID) {
1228             ret = -1;
1229             break;
1230         }
1231         wanted |= (1u << idx);
1232     }
1233     va_end(ap);
1234 
1235     if (ret == -1)
1236         return ret;
1237 
1238     return match_mod_masks(state, type, match, wanted);
1239 }
1240 
1241 /**
1242  * Returns 1 if the given group is active with the specified type(s), 0 if
1243  * not, or -1 if the group is invalid.
1244  */
1245 XKB_EXPORT int
xkb_state_layout_index_is_active(struct xkb_state * state,xkb_layout_index_t idx,enum xkb_state_component type)1246 xkb_state_layout_index_is_active(struct xkb_state *state,
1247                                 xkb_layout_index_t idx,
1248                                 enum xkb_state_component type)
1249 {
1250     int ret = 0;
1251 
1252     if (idx >= state->keymap->num_groups)
1253         return -1;
1254 
1255     if (type & XKB_STATE_LAYOUT_EFFECTIVE)
1256         ret |= (state->components.group == idx);
1257     if (type & XKB_STATE_LAYOUT_DEPRESSED)
1258         ret |= (state->components.base_group == (int32_t) idx);
1259     if (type & XKB_STATE_LAYOUT_LATCHED)
1260         ret |= (state->components.latched_group == (int32_t) idx);
1261     if (type & XKB_STATE_LAYOUT_LOCKED)
1262         ret |= (state->components.locked_group == (int32_t) idx);
1263 
1264     return ret;
1265 }
1266 
1267 /**
1268  * Returns 1 if the given modifier is active with the specified type(s), 0 if
1269  * not, or -1 if the modifier is invalid.
1270  */
1271 XKB_EXPORT int
xkb_state_layout_name_is_active(struct xkb_state * state,const char * name,enum xkb_state_component type)1272 xkb_state_layout_name_is_active(struct xkb_state *state, const char *name,
1273                                 enum xkb_state_component type)
1274 {
1275     xkb_layout_index_t idx = xkb_keymap_layout_get_index(state->keymap, name);
1276 
1277     if (idx == XKB_LAYOUT_INVALID)
1278         return -1;
1279 
1280     return xkb_state_layout_index_is_active(state, idx, type);
1281 }
1282 
1283 /**
1284  * Returns 1 if the given LED is active, 0 if not, or -1 if the LED is invalid.
1285  */
1286 XKB_EXPORT int
xkb_state_led_index_is_active(struct xkb_state * state,xkb_led_index_t idx)1287 xkb_state_led_index_is_active(struct xkb_state *state, xkb_led_index_t idx)
1288 {
1289     if (idx >= state->keymap->num_leds ||
1290         state->keymap->leds[idx].name == XKB_ATOM_NONE)
1291         return -1;
1292 
1293     return !!(state->components.leds & (1u << idx));
1294 }
1295 
1296 /**
1297  * Returns 1 if the given LED is active, 0 if not, or -1 if the LED is invalid.
1298  */
1299 XKB_EXPORT int
xkb_state_led_name_is_active(struct xkb_state * state,const char * name)1300 xkb_state_led_name_is_active(struct xkb_state *state, const char *name)
1301 {
1302     xkb_led_index_t idx = xkb_keymap_led_get_index(state->keymap, name);
1303 
1304     if (idx == XKB_LED_INVALID)
1305         return -1;
1306 
1307     return xkb_state_led_index_is_active(state, idx);
1308 }
1309 
1310 static xkb_mod_mask_t
key_get_consumed(struct xkb_state * state,const struct xkb_key * key)1311 key_get_consumed(struct xkb_state *state, const struct xkb_key *key)
1312 {
1313     const struct xkb_key_type *type;
1314     const struct xkb_key_type_entry *entry;
1315     xkb_mod_mask_t preserve;
1316     xkb_layout_index_t group;
1317 
1318     group = xkb_state_key_get_layout(state, key->keycode);
1319     if (group == XKB_LAYOUT_INVALID)
1320         return 0;
1321 
1322     type = key->groups[group].type;
1323 
1324     entry = get_entry_for_key_state(state, key, group);
1325     if (entry)
1326         preserve = entry->preserve.mask;
1327     else
1328         preserve = 0;
1329 
1330     return type->mods.mask & ~preserve;
1331 }
1332 
1333 /**
1334  * Tests to see if a modifier is used up by our translation of a
1335  * keycode to keysyms, taking note of the current modifier state and
1336  * the appropriate key type's preserve information, if any. This allows
1337  * the user to mask out the modifier in later processing of the
1338  * modifiers, e.g. when implementing hot keys or accelerators.
1339  *
1340  * See also, for example:
1341  * - XkbTranslateKeyCode(3), mod_rtrn return value, from libX11.
1342  * - gdk_keymap_translate_keyboard_state, consumed_modifiers return value,
1343  *   from gtk+.
1344  */
1345 XKB_EXPORT int
xkb_state_mod_index_is_consumed(struct xkb_state * state,xkb_keycode_t kc,xkb_mod_index_t idx)1346 xkb_state_mod_index_is_consumed(struct xkb_state *state, xkb_keycode_t kc,
1347                                 xkb_mod_index_t idx)
1348 {
1349     const struct xkb_key *key = XkbKey(state->keymap, kc);
1350 
1351     if (!key || idx >= xkb_keymap_num_mods(state->keymap))
1352         return -1;
1353 
1354     return !!((1u << idx) & key_get_consumed(state, key));
1355 }
1356 
1357 /**
1358  * Calculates which modifiers should be consumed during key processing,
1359  * and returns the mask with all these modifiers removed.  e.g. if
1360  * given a state of Alt and Shift active for a two-level alphabetic
1361  * key containing plus and equal on the first and second level
1362  * respectively, will return a mask of only Alt, as Shift has been
1363  * consumed by the type handling.
1364  */
1365 XKB_EXPORT xkb_mod_mask_t
xkb_state_mod_mask_remove_consumed(struct xkb_state * state,xkb_keycode_t kc,xkb_mod_mask_t mask)1366 xkb_state_mod_mask_remove_consumed(struct xkb_state *state, xkb_keycode_t kc,
1367                                    xkb_mod_mask_t mask)
1368 {
1369     const struct xkb_key *key = XkbKey(state->keymap, kc);
1370 
1371     if (!key)
1372         return 0;
1373 
1374     return mask & ~key_get_consumed(state, key);
1375 }
1376 
1377 XKB_EXPORT xkb_mod_mask_t
xkb_state_key_get_consumed_mods(struct xkb_state * state,xkb_keycode_t kc)1378 xkb_state_key_get_consumed_mods(struct xkb_state *state, xkb_keycode_t kc)
1379 {
1380     const struct xkb_key *key = XkbKey(state->keymap, kc);
1381 
1382     if (!key)
1383         return 0;
1384 
1385     return key_get_consumed(state, key);
1386 }
1387