2 * Copyright © 2010 Codethink Limited
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU Lesser General Public License as published
6 * by the Free Software Foundation; either version 2 of the licence or (at
7 * your option) any later version.
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.
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/>.
17 * Authors: Ryan Lortie <desrt@desrt.ca>
26 G_DEFINE_INTERFACE (GAction, g_action, G_TYPE_OBJECT)
31 * @short_description: An action interface
34 * #GAction represents a single named action.
36 * The main interface to an action is that it can be activated with
37 * g_action_activate(). This results in the 'activate' signal being
38 * emitted. An activation has a #GVariant parameter (which may be
39 * %NULL). The correct type for the parameter is determined by a static
40 * parameter type (which is given at construction time).
42 * An action may optionally have a state, in which case the state may be
43 * set with g_action_change_state(). This call takes a #GVariant. The
44 * correct type for the state is determined by a static state type
45 * (which is given at construction time).
47 * The state may have a hint associated with it, specifying its valid
50 * #GAction is merely the interface to the concept of an action, as
51 * described above. Various implementations of actions exist, including
54 * In all cases, the implementing class is responsible for storing the
55 * name of the action, the parameter type, the enabled state, the
56 * optional state type and the state and emitting the appropriate
57 * signals when these change. The implementor responsible for filtering
58 * calls to g_action_activate() and g_action_change_state() for type
59 * safety and for the state being enabled.
61 * Probably the only useful thing to do with a #GAction is to put it
62 * inside of a #GSimpleActionGroup.
67 * @get_name: the virtual function pointer for g_action_get_name()
68 * @get_parameter_type: the virtual function pointer for g_action_get_parameter_type()
69 * @get_state_type: the virtual function pointer for g_action_get_state_type()
70 * @get_state_hint: the virtual function pointer for g_action_get_state_hint()
71 * @get_enabled: the virtual function pointer for g_action_get_enabled()
72 * @get_state: the virtual function pointer for g_action_get_state()
73 * @change_state: the virtual function pointer for g_action_change_state()
74 * @activate: the virtual function pointer for g_action_activate(). Note that #GAction does not have an
75 * 'activate' signal but that implementations of it may have one.
77 * The virtual function table for #GAction.
83 g_action_default_init (GActionInterface *iface)
88 * The name of the action. This is mostly meaningful for identifying
89 * the action once it has been added to a #GActionGroup.
93 g_object_interface_install_property (iface,
94 g_param_spec_string ("name",
96 P_("The name used to invoke the action"),
99 G_PARAM_STATIC_STRINGS));
102 * GAction:parameter-type:
104 * The type of the parameter that must be given when activating the
109 g_object_interface_install_property (iface,
110 g_param_spec_boxed ("parameter-type",
111 P_("Parameter Type"),
112 P_("The type of GVariant passed to activate()"),
115 G_PARAM_STATIC_STRINGS));
120 * If @action is currently enabled.
122 * If the action is disabled then calls to g_action_activate() and
123 * g_action_change_state() have no effect.
127 g_object_interface_install_property (iface,
128 g_param_spec_boolean ("enabled",
130 P_("If the action can be activated"),
133 G_PARAM_STATIC_STRINGS));
136 * GAction:state-type:
138 * The #GVariantType of the state that the action has, or %NULL if the
139 * action is stateless.
143 g_object_interface_install_property (iface,
144 g_param_spec_boxed ("state-type",
146 P_("The type of the state kept by the action"),
149 G_PARAM_STATIC_STRINGS));
154 * The state of the action, or %NULL if the action is stateless.
158 g_object_interface_install_property (iface,
159 g_param_spec_variant ("state",
161 P_("The state the action is in"),
165 G_PARAM_STATIC_STRINGS));
169 * g_action_change_state:
170 * @action: a #GAction
171 * @value: the new state
173 * Request for the state of @action to be changed to @value.
175 * The action must be stateful and @value must be of the correct type.
176 * See g_action_get_state_type().
178 * This call merely requests a change. The action may refuse to change
179 * its state or may change its state to something other than @value.
180 * See g_action_get_state_hint().
182 * If the @value GVariant is floating, it is consumed.
187 g_action_change_state (GAction *action,
190 const GVariantType *state_type;
192 g_return_if_fail (G_IS_ACTION (action));
193 g_return_if_fail (value != NULL);
194 state_type = g_action_get_state_type (action);
195 g_return_if_fail (state_type != NULL);
196 g_return_if_fail (g_variant_is_of_type (value, state_type));
198 g_variant_ref_sink (value);
200 G_ACTION_GET_IFACE (action)
201 ->change_state (action, value);
203 g_variant_unref (value);
207 * g_action_get_state:
208 * @action: a #GAction
210 * Queries the current state of @action.
212 * If the action is not stateful then %NULL will be returned. If the
213 * action is stateful then the type of the return value is the type
214 * given by g_action_get_state_type().
216 * The return value (if non-%NULL) should be freed with
217 * g_variant_unref() when it is no longer required.
219 * Returns: (transfer full): the current state of the action
224 g_action_get_state (GAction *action)
226 g_return_val_if_fail (G_IS_ACTION (action), NULL);
228 return G_ACTION_GET_IFACE (action)
229 ->get_state (action);
234 * @action: a #GAction
236 * Queries the name of @action.
238 * Returns: the name of the action
243 g_action_get_name (GAction *action)
245 g_return_val_if_fail (G_IS_ACTION (action), NULL);
247 return G_ACTION_GET_IFACE (action)
252 * g_action_get_parameter_type:
253 * @action: a #GAction
255 * Queries the type of the parameter that must be given when activating
258 * When activating the action using g_action_activate(), the #GVariant
259 * given to that function must be of the type returned by this function.
261 * In the case that this function returns %NULL, you must not give any
262 * #GVariant, but %NULL instead.
264 * Returns: (allow-none): the parameter type
269 g_action_get_parameter_type (GAction *action)
271 g_return_val_if_fail (G_IS_ACTION (action), NULL);
273 return G_ACTION_GET_IFACE (action)
274 ->get_parameter_type (action);
278 * g_action_get_state_type:
279 * @action: a #GAction
281 * Queries the type of the state of @action.
283 * If the action is stateful (e.g. created with
284 * g_simple_action_new_stateful()) then this function returns the
285 * #GVariantType of the state. This is the type of the initial value
286 * given as the state. All calls to g_action_change_state() must give a
287 * #GVariant of this type and g_action_get_state() will return a
288 * #GVariant of the same type.
290 * If the action is not stateful (e.g. created with g_simple_action_new())
291 * then this function will return %NULL. In that case, g_action_get_state()
292 * will return %NULL and you must not call g_action_change_state().
294 * Returns: (allow-none): the state type, if the action is stateful
299 g_action_get_state_type (GAction *action)
301 g_return_val_if_fail (G_IS_ACTION (action), NULL);
303 return G_ACTION_GET_IFACE (action)
304 ->get_state_type (action);
308 * g_action_get_state_hint:
309 * @action: a #GAction
311 * Requests a hint about the valid range of values for the state of
314 * If %NULL is returned it either means that the action is not stateful
315 * or that there is no hint about the valid range of values for the
316 * state of the action.
318 * If a #GVariant array is returned then each item in the array is a
319 * possible value for the state. If a #GVariant pair (ie: two-tuple) is
320 * returned then the tuple specifies the inclusive lower and upper bound
321 * of valid values for the state.
323 * In any case, the information is merely a hint. It may be possible to
324 * have a state value outside of the hinted range and setting a value
325 * within the range may fail.
327 * The return value (if non-%NULL) should be freed with
328 * g_variant_unref() when it is no longer required.
330 * Returns: (transfer full): the state range hint
335 g_action_get_state_hint (GAction *action)
337 g_return_val_if_fail (G_IS_ACTION (action), NULL);
339 return G_ACTION_GET_IFACE (action)
340 ->get_state_hint (action);
344 * g_action_get_enabled:
345 * @action: a #GAction
347 * Checks if @action is currently enabled.
349 * An action must be enabled in order to be activated or in order to
350 * have its state changed from outside callers.
352 * Returns: whether the action is enabled
357 g_action_get_enabled (GAction *action)
359 g_return_val_if_fail (G_IS_ACTION (action), FALSE);
361 return G_ACTION_GET_IFACE (action)
362 ->get_enabled (action);
367 * @action: a #GAction
368 * @parameter: (allow-none): the parameter to the activation
370 * Activates the action.
372 * @parameter must be the correct type of parameter for the action (ie:
373 * the parameter type given at construction time). If the parameter
374 * type was %NULL then @parameter must also be %NULL.
376 * If the @parameter GVariant is floating, it is consumed.
381 g_action_activate (GAction *action,
384 g_return_if_fail (G_IS_ACTION (action));
386 if (parameter != NULL)
387 g_variant_ref_sink (parameter);
389 G_ACTION_GET_IFACE (action)
390 ->activate (action, parameter);
392 if (parameter != NULL)
393 g_variant_unref (parameter);
397 * g_action_name_is_valid:
398 * @action_name: an potential action name
400 * Checks if @action_name is valid.
402 * @action_name is valid if it consists only of alphanumeric characters,
403 * plus '-' and '.'. The empty string is not a valid action name.
405 * It is an error to call this function with a non-utf8 @action_name.
406 * @action_name must not be %NULL.
408 * Returns: %TRUE if @action_name is valid
413 g_action_name_is_valid (const gchar *action_name)
418 g_return_val_if_fail (action_name != NULL, FALSE);
420 for (i = 0; (c = action_name[i]); i++)
421 if (!g_ascii_isalnum (c) && c != '.' && c != '-')
428 * g_action_parse_detailed_name:
429 * @detailed_name: a detailed action name
430 * @action_name: (out): the action name
431 * @target_value: (out): the target value, or %NULL for no target
432 * @error: a pointer to a %NULL #GError, or %NULL
434 * Parses a detailed action name into its separate name and target
437 * Detailed action names can have three formats.
439 * The first format is used to represent an action name with no target
440 * value and consists of just an action name containing no whitespace
441 * nor the characters ':', '(' or ')'. For example: "app.action".
443 * The second format is used to represent an action with a target value
444 * that is a non-empty string consisting only of alphanumerics, plus '-'
445 * and '.'. In that case, the action name and target value are
446 * separated by a double colon ("::"). For example:
447 * "app.action::target".
449 * The third format is used to represent an action with any type of
450 * target value, including strings. The target value follows the action
451 * name, surrounded in parens. For example: "app.action(42)". The
452 * target value is parsed using g_variant_parse(). If a tuple-typed
453 * value is desired, it must be specified in the same way, resulting in
454 * two sets of parens, for example: "app.action((1,2,3))". A string
455 * target can be specified this way as well: "app.action('target')".
456 * For strings, this third format must be used if * target value is
457 * empty or contains characters other than alphanumerics, '-' and '.'.
459 * Returns: %TRUE if successful, else %FALSE with @error set
464 g_action_parse_detailed_name (const gchar *detailed_name,
466 GVariant **target_value,
473 /* For historical (compatibility) reasons, this function accepts some
474 * cases of invalid action names as long as they don't interfere with
475 * the separation of the action from the target value.
477 * We decide which format we have based on which we see first between
481 if (*detailed_name == '\0' || *detailed_name == ' ')
484 base_len = strcspn (detailed_name, ": ()");
485 target = detailed_name + base_len;
486 target_len = strlen (target);
495 if (target[1] != ':')
498 *target_value = g_variant_ref_sink (g_variant_new_string (target + 2));
503 if (target[target_len - 1] != ')')
506 *target_value = g_variant_parse (NULL, target + 1, target + target_len - 1, NULL, error);
507 if (*target_value == NULL)
513 *target_value = NULL;
517 *action_name = g_strndup (detailed_name, base_len);
525 g_set_error (error, G_VARIANT_PARSE_ERROR, G_VARIANT_PARSE_ERROR_FAILED,
526 "Detailed action name '%s' has invalid format", detailed_name);
528 g_prefix_error (error, "Detailed action name '%s' has invalid format: ", detailed_name);
535 * g_action_print_detailed_name:
536 * @action_name: a valid action name
537 * @target_value: (allow-none): a #GVariant target value, or %NULL
539 * Formats a detailed action name from @action_name and @target_value.
541 * It is an error to call this function with an invalid action name.
543 * This function is the opposite of
544 * g_action_parse_detailed_action_name(). It will produce a string that
545 * can be parsed back to the @action_name and @target_value by that
548 * See that function for the types of strings that will be printed by
551 * Returns: a detailed format string
556 g_action_print_detailed_name (const gchar *action_name,
557 GVariant *target_value)
559 g_return_val_if_fail (g_action_name_is_valid (action_name), NULL);
561 if (target_value == NULL)
562 return g_strdup (action_name);
564 if (g_variant_is_of_type (target_value, G_VARIANT_TYPE_STRING))
566 const gchar *str = g_variant_get_string (target_value, NULL);
568 if (g_action_name_is_valid (str))
569 return g_strconcat (action_name, "::", str, NULL);
573 GString *result = g_string_new (action_name);
574 g_string_append_c (result, '(');
575 g_variant_print_string (target_value, result, TRUE);
576 g_string_append_c (result, ')');
578 return g_string_free (result, FALSE);