1 /*
2 * Copyright © 2010 Codethink Limited
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General
15 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
16 *
17 * Authors: Ryan Lortie <desrt@desrt.ca>
18 */
19
20 #include "config.h"
21
22 #include "gsimpleaction.h"
23
24 #include "gaction.h"
25 #include "glibintl.h"
26
27 /**
28 * SECTION:gsimpleaction
29 * @title: GSimpleAction
30 * @short_description: A simple GAction implementation
31 * @include: gio/gio.h
32 *
33 * A #GSimpleAction is the obvious simple implementation of the #GAction
34 * interface. This is the easiest way to create an action for purposes of
35 * adding it to a #GSimpleActionGroup.
36 *
37 * See also #GtkAction.
38 */
39
40 /**
41 * GSimpleAction:
42 *
43 * #GSimpleAction is an opaque data structure and can only be accessed
44 * using the following functions.
45 **/
46
47 struct _GSimpleAction
48 {
49 GObject parent_instance;
50
51 gchar *name;
52 GVariantType *parameter_type;
53 gboolean enabled;
54 GVariant *state;
55 GVariant *state_hint;
56 gboolean state_set_already;
57 };
58
59 typedef GObjectClass GSimpleActionClass;
60
61 static void g_simple_action_iface_init (GActionInterface *iface);
62 G_DEFINE_TYPE_WITH_CODE (GSimpleAction, g_simple_action, G_TYPE_OBJECT,
63 G_IMPLEMENT_INTERFACE (G_TYPE_ACTION, g_simple_action_iface_init))
64
65 enum
66 {
67 PROP_NONE,
68 PROP_NAME,
69 PROP_PARAMETER_TYPE,
70 PROP_ENABLED,
71 PROP_STATE_TYPE,
72 PROP_STATE
73 };
74
75 enum
76 {
77 SIGNAL_CHANGE_STATE,
78 SIGNAL_ACTIVATE,
79 NR_SIGNALS
80 };
81
82 static guint g_simple_action_signals[NR_SIGNALS];
83
84 static const gchar *
g_simple_action_get_name(GAction * action)85 g_simple_action_get_name (GAction *action)
86 {
87 GSimpleAction *simple = G_SIMPLE_ACTION (action);
88
89 return simple->name;
90 }
91
92 static const GVariantType *
g_simple_action_get_parameter_type(GAction * action)93 g_simple_action_get_parameter_type (GAction *action)
94 {
95 GSimpleAction *simple = G_SIMPLE_ACTION (action);
96
97 return simple->parameter_type;
98 }
99
100 static const GVariantType *
g_simple_action_get_state_type(GAction * action)101 g_simple_action_get_state_type (GAction *action)
102 {
103 GSimpleAction *simple = G_SIMPLE_ACTION (action);
104
105 if (simple->state != NULL)
106 return g_variant_get_type (simple->state);
107 else
108 return NULL;
109 }
110
111 static GVariant *
g_simple_action_get_state_hint(GAction * action)112 g_simple_action_get_state_hint (GAction *action)
113 {
114 GSimpleAction *simple = G_SIMPLE_ACTION (action);
115
116 if (simple->state_hint != NULL)
117 return g_variant_ref (simple->state_hint);
118 else
119 return NULL;
120 }
121
122 static gboolean
g_simple_action_get_enabled(GAction * action)123 g_simple_action_get_enabled (GAction *action)
124 {
125 GSimpleAction *simple = G_SIMPLE_ACTION (action);
126
127 return simple->enabled;
128 }
129
130 static void
g_simple_action_change_state(GAction * action,GVariant * value)131 g_simple_action_change_state (GAction *action,
132 GVariant *value)
133 {
134 GSimpleAction *simple = G_SIMPLE_ACTION (action);
135
136 /* If the user connected a signal handler then they are responsible
137 * for handling state changes.
138 */
139 if (g_signal_has_handler_pending (action, g_simple_action_signals[SIGNAL_CHANGE_STATE], 0, TRUE))
140 g_signal_emit (action, g_simple_action_signals[SIGNAL_CHANGE_STATE], 0, value);
141
142 /* If not, then the default behaviour is to just set the state. */
143 else
144 g_simple_action_set_state (simple, value);
145 }
146
147 /**
148 * g_simple_action_set_state:
149 * @simple: a #GSimpleAction
150 * @value: the new #GVariant for the state
151 *
152 * Sets the state of the action.
153 *
154 * This directly updates the 'state' property to the given value.
155 *
156 * This should only be called by the implementor of the action. Users
157 * of the action should not attempt to directly modify the 'state'
158 * property. Instead, they should call g_action_change_state() to
159 * request the change.
160 *
161 * If the @value GVariant is floating, it is consumed.
162 *
163 * Since: 2.30
164 **/
165 void
g_simple_action_set_state(GSimpleAction * simple,GVariant * value)166 g_simple_action_set_state (GSimpleAction *simple,
167 GVariant *value)
168 {
169 g_return_if_fail (G_IS_SIMPLE_ACTION (simple));
170 g_return_if_fail (value != NULL);
171
172 {
173 const GVariantType *state_type;
174
175 state_type = simple->state ?
176 g_variant_get_type (simple->state) : NULL;
177 g_return_if_fail (state_type != NULL);
178 g_return_if_fail (g_variant_is_of_type (value, state_type));
179 }
180
181 g_variant_ref_sink (value);
182
183 if (!simple->state || !g_variant_equal (simple->state, value))
184 {
185 if (simple->state)
186 g_variant_unref (simple->state);
187
188 simple->state = g_variant_ref (value);
189
190 g_object_notify (G_OBJECT (simple), "state");
191 }
192
193 g_variant_unref (value);
194 }
195
196 static GVariant *
g_simple_action_get_state(GAction * action)197 g_simple_action_get_state (GAction *action)
198 {
199 GSimpleAction *simple = G_SIMPLE_ACTION (action);
200
201 return simple->state ? g_variant_ref (simple->state) : NULL;
202 }
203
204 static void
g_simple_action_activate(GAction * action,GVariant * parameter)205 g_simple_action_activate (GAction *action,
206 GVariant *parameter)
207 {
208 GSimpleAction *simple = G_SIMPLE_ACTION (action);
209
210 g_return_if_fail (simple->parameter_type == NULL ?
211 parameter == NULL :
212 (parameter != NULL &&
213 g_variant_is_of_type (parameter,
214 simple->parameter_type)));
215
216 if (parameter != NULL)
217 g_variant_ref_sink (parameter);
218
219 if (simple->enabled)
220 {
221 /* If the user connected a signal handler then they are responsible
222 * for handling activation.
223 */
224 if (g_signal_has_handler_pending (action, g_simple_action_signals[SIGNAL_ACTIVATE], 0, TRUE))
225 g_signal_emit (action, g_simple_action_signals[SIGNAL_ACTIVATE], 0, parameter);
226
227 /* If not, do some reasonable defaults for stateful actions. */
228 else if (simple->state)
229 {
230 /* If we have no parameter and this is a boolean action, toggle. */
231 if (parameter == NULL && g_variant_is_of_type (simple->state, G_VARIANT_TYPE_BOOLEAN))
232 {
233 gboolean was_enabled = g_variant_get_boolean (simple->state);
234 g_simple_action_change_state (action, g_variant_new_boolean (!was_enabled));
235 }
236
237 /* else, if the parameter and state type are the same, do a change-state */
238 else if (g_variant_is_of_type (simple->state, g_variant_get_type (parameter)))
239 g_simple_action_change_state (action, parameter);
240 }
241 }
242
243 if (parameter != NULL)
244 g_variant_unref (parameter);
245 }
246
247 static void
g_simple_action_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)248 g_simple_action_set_property (GObject *object,
249 guint prop_id,
250 const GValue *value,
251 GParamSpec *pspec)
252 {
253 GSimpleAction *action = G_SIMPLE_ACTION (object);
254
255 switch (prop_id)
256 {
257 case PROP_NAME:
258 action->name = g_strdup (g_value_get_string (value));
259 break;
260
261 case PROP_PARAMETER_TYPE:
262 action->parameter_type = g_value_dup_boxed (value);
263 break;
264
265 case PROP_ENABLED:
266 action->enabled = g_value_get_boolean (value);
267 break;
268
269 case PROP_STATE:
270 /* The first time we see this (during construct) we should just
271 * take the state as it was handed to us.
272 *
273 * After that, we should make sure we go through the same checks
274 * as the C API.
275 */
276 if (!action->state_set_already)
277 {
278 action->state = g_value_dup_variant (value);
279 action->state_set_already = TRUE;
280 }
281 else
282 g_simple_action_set_state (action, g_value_get_variant (value));
283
284 break;
285
286 default:
287 g_assert_not_reached ();
288 }
289 }
290
291 static void
g_simple_action_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)292 g_simple_action_get_property (GObject *object,
293 guint prop_id,
294 GValue *value,
295 GParamSpec *pspec)
296 {
297 GAction *action = G_ACTION (object);
298
299 switch (prop_id)
300 {
301 case PROP_NAME:
302 g_value_set_string (value, g_simple_action_get_name (action));
303 break;
304
305 case PROP_PARAMETER_TYPE:
306 g_value_set_boxed (value, g_simple_action_get_parameter_type (action));
307 break;
308
309 case PROP_ENABLED:
310 g_value_set_boolean (value, g_simple_action_get_enabled (action));
311 break;
312
313 case PROP_STATE_TYPE:
314 g_value_set_boxed (value, g_simple_action_get_state_type (action));
315 break;
316
317 case PROP_STATE:
318 g_value_take_variant (value, g_simple_action_get_state (action));
319 break;
320
321 default:
322 g_assert_not_reached ();
323 }
324 }
325
326 static void
g_simple_action_finalize(GObject * object)327 g_simple_action_finalize (GObject *object)
328 {
329 GSimpleAction *simple = G_SIMPLE_ACTION (object);
330
331 g_free (simple->name);
332 if (simple->parameter_type)
333 g_variant_type_free (simple->parameter_type);
334 if (simple->state)
335 g_variant_unref (simple->state);
336 if (simple->state_hint)
337 g_variant_unref (simple->state_hint);
338
339 G_OBJECT_CLASS (g_simple_action_parent_class)
340 ->finalize (object);
341 }
342
343 void
g_simple_action_init(GSimpleAction * simple)344 g_simple_action_init (GSimpleAction *simple)
345 {
346 simple->enabled = TRUE;
347 }
348
349 void
g_simple_action_iface_init(GActionInterface * iface)350 g_simple_action_iface_init (GActionInterface *iface)
351 {
352 iface->get_name = g_simple_action_get_name;
353 iface->get_parameter_type = g_simple_action_get_parameter_type;
354 iface->get_state_type = g_simple_action_get_state_type;
355 iface->get_state_hint = g_simple_action_get_state_hint;
356 iface->get_enabled = g_simple_action_get_enabled;
357 iface->get_state = g_simple_action_get_state;
358 iface->change_state = g_simple_action_change_state;
359 iface->activate = g_simple_action_activate;
360 }
361
362 void
g_simple_action_class_init(GSimpleActionClass * class)363 g_simple_action_class_init (GSimpleActionClass *class)
364 {
365 GObjectClass *object_class = G_OBJECT_CLASS (class);
366
367 object_class->set_property = g_simple_action_set_property;
368 object_class->get_property = g_simple_action_get_property;
369 object_class->finalize = g_simple_action_finalize;
370
371 /**
372 * GSimpleAction::activate:
373 * @simple: the #GSimpleAction
374 * @parameter: (nullable): the parameter to the activation, or %NULL if it has
375 * no parameter
376 *
377 * Indicates that the action was just activated.
378 *
379 * @parameter will always be of the expected type, i.e. the parameter type
380 * specified when the action was created. If an incorrect type is given when
381 * activating the action, this signal is not emitted.
382 *
383 * Since GLib 2.40, if no handler is connected to this signal then the
384 * default behaviour for boolean-stated actions with a %NULL parameter
385 * type is to toggle them via the #GSimpleAction::change-state signal.
386 * For stateful actions where the state type is equal to the parameter
387 * type, the default is to forward them directly to
388 * #GSimpleAction::change-state. This should allow almost all users
389 * of #GSimpleAction to connect only one handler or the other.
390 *
391 * Since: 2.28
392 */
393 g_simple_action_signals[SIGNAL_ACTIVATE] =
394 g_signal_new (I_("activate"),
395 G_TYPE_SIMPLE_ACTION,
396 G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
397 0, NULL, NULL,
398 NULL,
399 G_TYPE_NONE, 1,
400 G_TYPE_VARIANT);
401
402 /**
403 * GSimpleAction::change-state:
404 * @simple: the #GSimpleAction
405 * @value: (nullable): the requested value for the state
406 *
407 * Indicates that the action just received a request to change its
408 * state.
409 *
410 * @value will always be of the correct state type, i.e. the type of the
411 * initial state passed to g_simple_action_new_stateful(). If an incorrect
412 * type is given when requesting to change the state, this signal is not
413 * emitted.
414 *
415 * If no handler is connected to this signal then the default
416 * behaviour is to call g_simple_action_set_state() to set the state
417 * to the requested value. If you connect a signal handler then no
418 * default action is taken. If the state should change then you must
419 * call g_simple_action_set_state() from the handler.
420 *
421 * An example of a 'change-state' handler:
422 * |[<!-- language="C" -->
423 * static void
424 * change_volume_state (GSimpleAction *action,
425 * GVariant *value,
426 * gpointer user_data)
427 * {
428 * gint requested;
429 *
430 * requested = g_variant_get_int32 (value);
431 *
432 * // Volume only goes from 0 to 10
433 * if (0 <= requested && requested <= 10)
434 * g_simple_action_set_state (action, value);
435 * }
436 * ]|
437 *
438 * The handler need not set the state to the requested value.
439 * It could set it to any value at all, or take some other action.
440 *
441 * Since: 2.30
442 */
443 g_simple_action_signals[SIGNAL_CHANGE_STATE] =
444 g_signal_new (I_("change-state"),
445 G_TYPE_SIMPLE_ACTION,
446 G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
447 0, NULL, NULL,
448 NULL,
449 G_TYPE_NONE, 1,
450 G_TYPE_VARIANT);
451
452 /**
453 * GSimpleAction:name:
454 *
455 * The name of the action. This is mostly meaningful for identifying
456 * the action once it has been added to a #GSimpleActionGroup.
457 *
458 * Since: 2.28
459 **/
460 g_object_class_install_property (object_class, PROP_NAME,
461 g_param_spec_string ("name",
462 P_("Action Name"),
463 P_("The name used to invoke the action"),
464 NULL,
465 G_PARAM_READWRITE |
466 G_PARAM_CONSTRUCT_ONLY |
467 G_PARAM_STATIC_STRINGS));
468
469 /**
470 * GSimpleAction:parameter-type:
471 *
472 * The type of the parameter that must be given when activating the
473 * action.
474 *
475 * Since: 2.28
476 **/
477 g_object_class_install_property (object_class, PROP_PARAMETER_TYPE,
478 g_param_spec_boxed ("parameter-type",
479 P_("Parameter Type"),
480 P_("The type of GVariant passed to activate()"),
481 G_TYPE_VARIANT_TYPE,
482 G_PARAM_READWRITE |
483 G_PARAM_CONSTRUCT_ONLY |
484 G_PARAM_STATIC_STRINGS));
485
486 /**
487 * GSimpleAction:enabled:
488 *
489 * If @action is currently enabled.
490 *
491 * If the action is disabled then calls to g_action_activate() and
492 * g_action_change_state() have no effect.
493 *
494 * Since: 2.28
495 **/
496 g_object_class_install_property (object_class, PROP_ENABLED,
497 g_param_spec_boolean ("enabled",
498 P_("Enabled"),
499 P_("If the action can be activated"),
500 TRUE,
501 G_PARAM_READWRITE |
502 G_PARAM_STATIC_STRINGS));
503
504 /**
505 * GSimpleAction:state-type:
506 *
507 * The #GVariantType of the state that the action has, or %NULL if the
508 * action is stateless.
509 *
510 * Since: 2.28
511 **/
512 g_object_class_install_property (object_class, PROP_STATE_TYPE,
513 g_param_spec_boxed ("state-type",
514 P_("State Type"),
515 P_("The type of the state kept by the action"),
516 G_TYPE_VARIANT_TYPE,
517 G_PARAM_READABLE |
518 G_PARAM_STATIC_STRINGS));
519
520 /**
521 * GSimpleAction:state:
522 *
523 * The state of the action, or %NULL if the action is stateless.
524 *
525 * Since: 2.28
526 **/
527 g_object_class_install_property (object_class, PROP_STATE,
528 g_param_spec_variant ("state",
529 P_("State"),
530 P_("The state the action is in"),
531 G_VARIANT_TYPE_ANY,
532 NULL,
533 G_PARAM_READWRITE | G_PARAM_CONSTRUCT |
534 G_PARAM_STATIC_STRINGS));
535 }
536
537 /**
538 * g_simple_action_set_enabled:
539 * @simple: a #GSimpleAction
540 * @enabled: whether the action is enabled
541 *
542 * Sets the action as enabled or not.
543 *
544 * An action must be enabled in order to be activated or in order to
545 * have its state changed from outside callers.
546 *
547 * This should only be called by the implementor of the action. Users
548 * of the action should not attempt to modify its enabled flag.
549 *
550 * Since: 2.28
551 **/
552 void
g_simple_action_set_enabled(GSimpleAction * simple,gboolean enabled)553 g_simple_action_set_enabled (GSimpleAction *simple,
554 gboolean enabled)
555 {
556 g_return_if_fail (G_IS_SIMPLE_ACTION (simple));
557
558 enabled = !!enabled;
559
560 if (simple->enabled != enabled)
561 {
562 simple->enabled = enabled;
563 g_object_notify (G_OBJECT (simple), "enabled");
564 }
565 }
566
567 /**
568 * g_simple_action_set_state_hint:
569 * @simple: a #GSimpleAction
570 * @state_hint: (nullable): a #GVariant representing the state hint
571 *
572 * Sets the state hint for the action.
573 *
574 * See g_action_get_state_hint() for more information about
575 * action state hints.
576 *
577 * Since: 2.44
578 **/
579 void
g_simple_action_set_state_hint(GSimpleAction * simple,GVariant * state_hint)580 g_simple_action_set_state_hint (GSimpleAction *simple,
581 GVariant *state_hint)
582 {
583 g_return_if_fail (G_IS_SIMPLE_ACTION (simple));
584
585 if (simple->state_hint != NULL)
586 {
587 g_variant_unref (simple->state_hint);
588 simple->state_hint = NULL;
589 }
590
591 if (state_hint != NULL)
592 simple->state_hint = g_variant_ref (state_hint);
593 }
594
595 /**
596 * g_simple_action_new:
597 * @name: the name of the action
598 * @parameter_type: (nullable): the type of parameter that will be passed to
599 * handlers for the #GSimpleAction::activate signal, or %NULL for no parameter
600 *
601 * Creates a new action.
602 *
603 * The created action is stateless. See g_simple_action_new_stateful() to create
604 * an action that has state.
605 *
606 * Returns: a new #GSimpleAction
607 *
608 * Since: 2.28
609 **/
610 GSimpleAction *
g_simple_action_new(const gchar * name,const GVariantType * parameter_type)611 g_simple_action_new (const gchar *name,
612 const GVariantType *parameter_type)
613 {
614 g_return_val_if_fail (name != NULL, NULL);
615
616 return g_object_new (G_TYPE_SIMPLE_ACTION,
617 "name", name,
618 "parameter-type", parameter_type,
619 NULL);
620 }
621
622 /**
623 * g_simple_action_new_stateful:
624 * @name: the name of the action
625 * @parameter_type: (nullable): the type of the parameter that will be passed to
626 * handlers for the #GSimpleAction::activate signal, or %NULL for no parameter
627 * @state: the initial state of the action
628 *
629 * Creates a new stateful action.
630 *
631 * All future state values must have the same #GVariantType as the initial
632 * @state.
633 *
634 * If the @state #GVariant is floating, it is consumed.
635 *
636 * Returns: a new #GSimpleAction
637 *
638 * Since: 2.28
639 **/
640 GSimpleAction *
g_simple_action_new_stateful(const gchar * name,const GVariantType * parameter_type,GVariant * state)641 g_simple_action_new_stateful (const gchar *name,
642 const GVariantType *parameter_type,
643 GVariant *state)
644 {
645 return g_object_new (G_TYPE_SIMPLE_ACTION,
646 "name", name,
647 "parameter-type", parameter_type,
648 "state", state,
649 NULL);
650 }
651