2 * Copyright © 2010 Codethink Limited
4 * SPDX-License-Identifier: LGPL-2.1-or-later
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library 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 GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General
17 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
19 * Authors: Ryan Lortie <desrt@desrt.ca>
28 G_DEFINE_INTERFACE (GAction, g_action, G_TYPE_OBJECT)
33 * @short_description: An action interface
36 * #GAction represents a single named action.
38 * The main interface to an action is that it can be activated with
39 * g_action_activate(). This results in the 'activate' signal being
40 * emitted. An activation has a #GVariant parameter (which may be
41 * %NULL). The correct type for the parameter is determined by a static
42 * parameter type (which is given at construction time).
44 * An action may optionally have a state, in which case the state may be
45 * set with g_action_change_state(). This call takes a #GVariant. The
46 * correct type for the state is determined by a static state type
47 * (which is given at construction time).
49 * The state may have a hint associated with it, specifying its valid
52 * #GAction is merely the interface to the concept of an action, as
53 * described above. Various implementations of actions exist, including
56 * In all cases, the implementing class is responsible for storing the
57 * name of the action, the parameter type, the enabled state, the
58 * optional state type and the state and emitting the appropriate
59 * signals when these change. The implementor is responsible for filtering
60 * calls to g_action_activate() and g_action_change_state() for type
61 * safety and for the state being enabled.
63 * Probably the only useful thing to do with a #GAction is to put it
64 * inside of a #GSimpleActionGroup.
70 * #GAction is an opaque data structure and can only be accessed
71 * using the following functions.
76 * @get_name: the virtual function pointer for g_action_get_name()
77 * @get_parameter_type: the virtual function pointer for g_action_get_parameter_type()
78 * @get_state_type: the virtual function pointer for g_action_get_state_type()
79 * @get_state_hint: the virtual function pointer for g_action_get_state_hint()
80 * @get_enabled: the virtual function pointer for g_action_get_enabled()
81 * @get_state: the virtual function pointer for g_action_get_state()
82 * @change_state: the virtual function pointer for g_action_change_state()
83 * @activate: the virtual function pointer for g_action_activate(). Note that #GAction does not have an
84 * 'activate' signal but that implementations of it may have one.
86 * The virtual function table for #GAction.
92 g_action_default_init (GActionInterface *iface)
97 * The name of the action. This is mostly meaningful for identifying
98 * the action once it has been added to a #GActionGroup. It is immutable.
102 g_object_interface_install_property (iface,
103 g_param_spec_string ("name",
105 P_("The name used to invoke the action"),
108 G_PARAM_STATIC_STRINGS));
111 * GAction:parameter-type:
113 * The type of the parameter that must be given when activating the
114 * action. This is immutable, and may be %NULL if no parameter is needed when
115 * activating the action.
119 g_object_interface_install_property (iface,
120 g_param_spec_boxed ("parameter-type",
121 P_("Parameter Type"),
122 P_("The type of GVariant passed to activate()"),
125 G_PARAM_STATIC_STRINGS));
130 * If @action is currently enabled.
132 * If the action is disabled then calls to g_action_activate() and
133 * g_action_change_state() have no effect.
137 g_object_interface_install_property (iface,
138 g_param_spec_boolean ("enabled",
140 P_("If the action can be activated"),
143 G_PARAM_STATIC_STRINGS));
146 * GAction:state-type:
148 * The #GVariantType of the state that the action has, or %NULL if the
149 * action is stateless. This is immutable.
153 g_object_interface_install_property (iface,
154 g_param_spec_boxed ("state-type",
156 P_("The type of the state kept by the action"),
159 G_PARAM_STATIC_STRINGS));
164 * The state of the action, or %NULL if the action is stateless.
168 g_object_interface_install_property (iface,
169 g_param_spec_variant ("state",
171 P_("The state the action is in"),
175 G_PARAM_STATIC_STRINGS));
179 * g_action_change_state:
180 * @action: a #GAction
181 * @value: the new state
183 * Request for the state of @action to be changed to @value.
185 * The action must be stateful and @value must be of the correct type.
186 * See g_action_get_state_type().
188 * This call merely requests a change. The action may refuse to change
189 * its state or may change its state to something other than @value.
190 * See g_action_get_state_hint().
192 * If the @value GVariant is floating, it is consumed.
197 g_action_change_state (GAction *action,
200 const GVariantType *state_type;
202 g_return_if_fail (G_IS_ACTION (action));
203 g_return_if_fail (value != NULL);
204 state_type = g_action_get_state_type (action);
205 g_return_if_fail (state_type != NULL);
206 g_return_if_fail (g_variant_is_of_type (value, state_type));
208 g_variant_ref_sink (value);
210 G_ACTION_GET_IFACE (action)
211 ->change_state (action, value);
213 g_variant_unref (value);
217 * g_action_get_state:
218 * @action: a #GAction
220 * Queries the current state of @action.
222 * If the action is not stateful then %NULL will be returned. If the
223 * action is stateful then the type of the return value is the type
224 * given by g_action_get_state_type().
226 * The return value (if non-%NULL) should be freed with
227 * g_variant_unref() when it is no longer required.
229 * Returns: (nullable) (transfer full): the current state of the action
234 g_action_get_state (GAction *action)
236 g_return_val_if_fail (G_IS_ACTION (action), NULL);
238 return G_ACTION_GET_IFACE (action)
239 ->get_state (action);
244 * @action: a #GAction
246 * Queries the name of @action.
248 * Returns: the name of the action
253 g_action_get_name (GAction *action)
255 g_return_val_if_fail (G_IS_ACTION (action), NULL);
257 return G_ACTION_GET_IFACE (action)
262 * g_action_get_parameter_type:
263 * @action: a #GAction
265 * Queries the type of the parameter that must be given when activating
268 * When activating the action using g_action_activate(), the #GVariant
269 * given to that function must be of the type returned by this function.
271 * In the case that this function returns %NULL, you must not give any
272 * #GVariant, but %NULL instead.
274 * Returns: (nullable): the parameter type
279 g_action_get_parameter_type (GAction *action)
281 g_return_val_if_fail (G_IS_ACTION (action), NULL);
283 return G_ACTION_GET_IFACE (action)
284 ->get_parameter_type (action);
288 * g_action_get_state_type:
289 * @action: a #GAction
291 * Queries the type of the state of @action.
293 * If the action is stateful (e.g. created with
294 * g_simple_action_new_stateful()) then this function returns the
295 * #GVariantType of the state. This is the type of the initial value
296 * given as the state. All calls to g_action_change_state() must give a
297 * #GVariant of this type and g_action_get_state() will return a
298 * #GVariant of the same type.
300 * If the action is not stateful (e.g. created with g_simple_action_new())
301 * then this function will return %NULL. In that case, g_action_get_state()
302 * will return %NULL and you must not call g_action_change_state().
304 * Returns: (nullable): the state type, if the action is stateful
309 g_action_get_state_type (GAction *action)
311 g_return_val_if_fail (G_IS_ACTION (action), NULL);
313 return G_ACTION_GET_IFACE (action)
314 ->get_state_type (action);
318 * g_action_get_state_hint:
319 * @action: a #GAction
321 * Requests a hint about the valid range of values for the state of
324 * If %NULL is returned it either means that the action is not stateful
325 * or that there is no hint about the valid range of values for the
326 * state of the action.
328 * If a #GVariant array is returned then each item in the array is a
329 * possible value for the state. If a #GVariant pair (ie: two-tuple) is
330 * returned then the tuple specifies the inclusive lower and upper bound
331 * of valid values for the state.
333 * In any case, the information is merely a hint. It may be possible to
334 * have a state value outside of the hinted range and setting a value
335 * within the range may fail.
337 * The return value (if non-%NULL) should be freed with
338 * g_variant_unref() when it is no longer required.
340 * Returns: (nullable) (transfer full): the state range hint
345 g_action_get_state_hint (GAction *action)
347 g_return_val_if_fail (G_IS_ACTION (action), NULL);
349 return G_ACTION_GET_IFACE (action)
350 ->get_state_hint (action);
354 * g_action_get_enabled:
355 * @action: a #GAction
357 * Checks if @action is currently enabled.
359 * An action must be enabled in order to be activated or in order to
360 * have its state changed from outside callers.
362 * Returns: whether the action is enabled
367 g_action_get_enabled (GAction *action)
369 g_return_val_if_fail (G_IS_ACTION (action), FALSE);
371 return G_ACTION_GET_IFACE (action)
372 ->get_enabled (action);
377 * @action: a #GAction
378 * @parameter: (nullable): the parameter to the activation
380 * Activates the action.
382 * @parameter must be the correct type of parameter for the action (ie:
383 * the parameter type given at construction time). If the parameter
384 * type was %NULL then @parameter must also be %NULL.
386 * If the @parameter GVariant is floating, it is consumed.
391 g_action_activate (GAction *action,
394 g_return_if_fail (G_IS_ACTION (action));
396 if (parameter != NULL)
397 g_variant_ref_sink (parameter);
399 G_ACTION_GET_IFACE (action)
400 ->activate (action, parameter);
402 if (parameter != NULL)
403 g_variant_unref (parameter);
407 * g_action_name_is_valid:
408 * @action_name: a potential action name
410 * Checks if @action_name is valid.
412 * @action_name is valid if it consists only of alphanumeric characters,
413 * plus '-' and '.'. The empty string is not a valid action name.
415 * It is an error to call this function with a non-utf8 @action_name.
416 * @action_name must not be %NULL.
418 * Returns: %TRUE if @action_name is valid
423 g_action_name_is_valid (const gchar *action_name)
428 g_return_val_if_fail (action_name != NULL, FALSE);
430 for (i = 0; (c = action_name[i]); i++)
431 if (!g_ascii_isalnum (c) && c != '.' && c != '-')
438 * g_action_parse_detailed_name:
439 * @detailed_name: a detailed action name
440 * @action_name: (out) (optional) (not nullable) (transfer full): the action name
441 * @target_value: (out) (optional) (nullable) (transfer full): the target value,
442 * or %NULL for no target
443 * @error: a pointer to a %NULL #GError, or %NULL
445 * Parses a detailed action name into its separate name and target
448 * Detailed action names can have three formats.
450 * The first format is used to represent an action name with no target
451 * value and consists of just an action name containing no whitespace
452 * nor the characters `:`, `(` or `)`. For example: `app.action`.
454 * The second format is used to represent an action with a target value
455 * that is a non-empty string consisting only of alphanumerics, plus `-`
456 * and `.`. In that case, the action name and target value are
457 * separated by a double colon (`::`). For example:
458 * `app.action::target`.
460 * The third format is used to represent an action with any type of
461 * target value, including strings. The target value follows the action
462 * name, surrounded in parens. For example: `app.action(42)`. The
463 * target value is parsed using g_variant_parse(). If a tuple-typed
464 * value is desired, it must be specified in the same way, resulting in
465 * two sets of parens, for example: `app.action((1,2,3))`. A string
466 * target can be specified this way as well: `app.action('target')`.
467 * For strings, this third format must be used if target value is
468 * empty or contains characters other than alphanumerics, `-` and `.`.
470 * If this function returns %TRUE, a non-%NULL value is guaranteed to be returned
471 * in @action_name (if a pointer is passed in). A %NULL value may still be
472 * returned in @target_value, as the @detailed_name may not contain a target.
474 * If returned, the #GVariant in @target_value is guaranteed to not be floating.
476 * Returns: %TRUE if successful, else %FALSE with @error set
481 g_action_parse_detailed_name (const gchar *detailed_name,
483 GVariant **target_value,
490 /* For historical (compatibility) reasons, this function accepts some
491 * cases of invalid action names as long as they don't interfere with
492 * the separation of the action from the target value.
494 * We decide which format we have based on which we see first between
498 if (*detailed_name == '\0' || *detailed_name == ' ')
501 base_len = strcspn (detailed_name, ": ()");
502 target = detailed_name + base_len;
503 target_len = strlen (target);
512 if (target[1] != ':')
515 *target_value = g_variant_ref_sink (g_variant_new_string (target + 2));
520 if (target[target_len - 1] != ')')
523 *target_value = g_variant_parse (NULL, target + 1, target + target_len - 1, NULL, error);
524 if (*target_value == NULL)
530 *target_value = NULL;
534 *action_name = g_strndup (detailed_name, base_len);
542 g_set_error (error, G_VARIANT_PARSE_ERROR, G_VARIANT_PARSE_ERROR_FAILED,
543 "Detailed action name '%s' has invalid format", detailed_name);
545 g_prefix_error (error, "Detailed action name '%s' has invalid format: ", detailed_name);
552 * g_action_print_detailed_name:
553 * @action_name: a valid action name
554 * @target_value: (nullable): a #GVariant target value, or %NULL
556 * Formats a detailed action name from @action_name and @target_value.
558 * It is an error to call this function with an invalid action name.
560 * This function is the opposite of g_action_parse_detailed_name().
561 * It will produce a string that can be parsed back to the @action_name
562 * and @target_value by that function.
564 * See that function for the types of strings that will be printed by
567 * Returns: a detailed format string
572 g_action_print_detailed_name (const gchar *action_name,
573 GVariant *target_value)
575 g_return_val_if_fail (g_action_name_is_valid (action_name), NULL);
577 if (target_value == NULL)
578 return g_strdup (action_name);
580 if (g_variant_is_of_type (target_value, G_VARIANT_TYPE_STRING))
582 const gchar *str = g_variant_get_string (target_value, NULL);
584 if (g_action_name_is_valid (str))
585 return g_strconcat (action_name, "::", str, NULL);
589 GString *result = g_string_new (action_name);
590 g_string_append_c (result, '(');
591 g_variant_print_string (target_value, result, TRUE);
592 g_string_append_c (result, ')');
594 return g_string_free (result, FALSE);