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 is 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.
68 * #GAction is an opaque data structure and can only be accessed
69 * using the following functions.
74 * @get_name: the virtual function pointer for g_action_get_name()
75 * @get_parameter_type: the virtual function pointer for g_action_get_parameter_type()
76 * @get_state_type: the virtual function pointer for g_action_get_state_type()
77 * @get_state_hint: the virtual function pointer for g_action_get_state_hint()
78 * @get_enabled: the virtual function pointer for g_action_get_enabled()
79 * @get_state: the virtual function pointer for g_action_get_state()
80 * @change_state: the virtual function pointer for g_action_change_state()
81 * @activate: the virtual function pointer for g_action_activate(). Note that #GAction does not have an
82 * 'activate' signal but that implementations of it may have one.
84 * The virtual function table for #GAction.
90 g_action_default_init (GActionInterface
*iface
)
95 * The name of the action. This is mostly meaningful for identifying
96 * the action once it has been added to a #GActionGroup. It is immutable.
100 g_object_interface_install_property (iface
,
101 g_param_spec_string ("name",
103 P_("The name used to invoke the action"),
106 G_PARAM_STATIC_STRINGS
));
109 * GAction:parameter-type:
111 * The type of the parameter that must be given when activating the
112 * action. This is immutable, and may be %NULL if no parameter is needed when
113 * activating the action.
117 g_object_interface_install_property (iface
,
118 g_param_spec_boxed ("parameter-type",
119 P_("Parameter Type"),
120 P_("The type of GVariant passed to activate()"),
123 G_PARAM_STATIC_STRINGS
));
128 * If @action is currently enabled.
130 * If the action is disabled then calls to g_action_activate() and
131 * g_action_change_state() have no effect.
135 g_object_interface_install_property (iface
,
136 g_param_spec_boolean ("enabled",
138 P_("If the action can be activated"),
141 G_PARAM_STATIC_STRINGS
));
144 * GAction:state-type:
146 * The #GVariantType of the state that the action has, or %NULL if the
147 * action is stateless. This is immutable.
151 g_object_interface_install_property (iface
,
152 g_param_spec_boxed ("state-type",
154 P_("The type of the state kept by the action"),
157 G_PARAM_STATIC_STRINGS
));
162 * The state of the action, or %NULL if the action is stateless.
166 g_object_interface_install_property (iface
,
167 g_param_spec_variant ("state",
169 P_("The state the action is in"),
173 G_PARAM_STATIC_STRINGS
));
177 * g_action_change_state:
178 * @action: a #GAction
179 * @value: the new state
181 * Request for the state of @action to be changed to @value.
183 * The action must be stateful and @value must be of the correct type.
184 * See g_action_get_state_type().
186 * This call merely requests a change. The action may refuse to change
187 * its state or may change its state to something other than @value.
188 * See g_action_get_state_hint().
190 * If the @value GVariant is floating, it is consumed.
195 g_action_change_state (GAction
*action
,
198 const GVariantType
*state_type
;
200 g_return_if_fail (G_IS_ACTION (action
));
201 g_return_if_fail (value
!= NULL
);
202 state_type
= g_action_get_state_type (action
);
203 g_return_if_fail (state_type
!= NULL
);
204 g_return_if_fail (g_variant_is_of_type (value
, state_type
));
206 g_variant_ref_sink (value
);
208 G_ACTION_GET_IFACE (action
)
209 ->change_state (action
, value
);
211 g_variant_unref (value
);
215 * g_action_get_state:
216 * @action: a #GAction
218 * Queries the current state of @action.
220 * If the action is not stateful then %NULL will be returned. If the
221 * action is stateful then the type of the return value is the type
222 * given by g_action_get_state_type().
224 * The return value (if non-%NULL) should be freed with
225 * g_variant_unref() when it is no longer required.
227 * Returns: (transfer full): the current state of the action
232 g_action_get_state (GAction
*action
)
234 g_return_val_if_fail (G_IS_ACTION (action
), NULL
);
236 return G_ACTION_GET_IFACE (action
)
237 ->get_state (action
);
242 * @action: a #GAction
244 * Queries the name of @action.
246 * Returns: the name of the action
251 g_action_get_name (GAction
*action
)
253 g_return_val_if_fail (G_IS_ACTION (action
), NULL
);
255 return G_ACTION_GET_IFACE (action
)
260 * g_action_get_parameter_type:
261 * @action: a #GAction
263 * Queries the type of the parameter that must be given when activating
266 * When activating the action using g_action_activate(), the #GVariant
267 * given to that function must be of the type returned by this function.
269 * In the case that this function returns %NULL, you must not give any
270 * #GVariant, but %NULL instead.
272 * Returns: (nullable): the parameter type
277 g_action_get_parameter_type (GAction
*action
)
279 g_return_val_if_fail (G_IS_ACTION (action
), NULL
);
281 return G_ACTION_GET_IFACE (action
)
282 ->get_parameter_type (action
);
286 * g_action_get_state_type:
287 * @action: a #GAction
289 * Queries the type of the state of @action.
291 * If the action is stateful (e.g. created with
292 * g_simple_action_new_stateful()) then this function returns the
293 * #GVariantType of the state. This is the type of the initial value
294 * given as the state. All calls to g_action_change_state() must give a
295 * #GVariant of this type and g_action_get_state() will return a
296 * #GVariant of the same type.
298 * If the action is not stateful (e.g. created with g_simple_action_new())
299 * then this function will return %NULL. In that case, g_action_get_state()
300 * will return %NULL and you must not call g_action_change_state().
302 * Returns: (nullable): the state type, if the action is stateful
307 g_action_get_state_type (GAction
*action
)
309 g_return_val_if_fail (G_IS_ACTION (action
), NULL
);
311 return G_ACTION_GET_IFACE (action
)
312 ->get_state_type (action
);
316 * g_action_get_state_hint:
317 * @action: a #GAction
319 * Requests a hint about the valid range of values for the state of
322 * If %NULL is returned it either means that the action is not stateful
323 * or that there is no hint about the valid range of values for the
324 * state of the action.
326 * If a #GVariant array is returned then each item in the array is a
327 * possible value for the state. If a #GVariant pair (ie: two-tuple) is
328 * returned then the tuple specifies the inclusive lower and upper bound
329 * of valid values for the state.
331 * In any case, the information is merely a hint. It may be possible to
332 * have a state value outside of the hinted range and setting a value
333 * within the range may fail.
335 * The return value (if non-%NULL) should be freed with
336 * g_variant_unref() when it is no longer required.
338 * Returns: (nullable) (transfer full): the state range hint
343 g_action_get_state_hint (GAction
*action
)
345 g_return_val_if_fail (G_IS_ACTION (action
), NULL
);
347 return G_ACTION_GET_IFACE (action
)
348 ->get_state_hint (action
);
352 * g_action_get_enabled:
353 * @action: a #GAction
355 * Checks if @action is currently enabled.
357 * An action must be enabled in order to be activated or in order to
358 * have its state changed from outside callers.
360 * Returns: whether the action is enabled
365 g_action_get_enabled (GAction
*action
)
367 g_return_val_if_fail (G_IS_ACTION (action
), FALSE
);
369 return G_ACTION_GET_IFACE (action
)
370 ->get_enabled (action
);
375 * @action: a #GAction
376 * @parameter: (nullable): the parameter to the activation
378 * Activates the action.
380 * @parameter must be the correct type of parameter for the action (ie:
381 * the parameter type given at construction time). If the parameter
382 * type was %NULL then @parameter must also be %NULL.
384 * If the @parameter GVariant is floating, it is consumed.
389 g_action_activate (GAction
*action
,
392 g_return_if_fail (G_IS_ACTION (action
));
394 if (parameter
!= NULL
)
395 g_variant_ref_sink (parameter
);
397 G_ACTION_GET_IFACE (action
)
398 ->activate (action
, parameter
);
400 if (parameter
!= NULL
)
401 g_variant_unref (parameter
);
405 * g_action_name_is_valid:
406 * @action_name: an potential action name
408 * Checks if @action_name is valid.
410 * @action_name is valid if it consists only of alphanumeric characters,
411 * plus '-' and '.'. The empty string is not a valid action name.
413 * It is an error to call this function with a non-utf8 @action_name.
414 * @action_name must not be %NULL.
416 * Returns: %TRUE if @action_name is valid
421 g_action_name_is_valid (const gchar
*action_name
)
426 g_return_val_if_fail (action_name
!= NULL
, FALSE
);
428 for (i
= 0; (c
= action_name
[i
]); i
++)
429 if (!g_ascii_isalnum (c
) && c
!= '.' && c
!= '-')
436 * g_action_parse_detailed_name:
437 * @detailed_name: a detailed action name
438 * @action_name: (out): the action name
439 * @target_value: (out): the target value, or %NULL for no target
440 * @error: a pointer to a %NULL #GError, or %NULL
442 * Parses a detailed action name into its separate name and target
445 * Detailed action names can have three formats.
447 * The first format is used to represent an action name with no target
448 * value and consists of just an action name containing no whitespace
449 * nor the characters ':', '(' or ')'. For example: "app.action".
451 * The second format is used to represent an action with a target value
452 * that is a non-empty string consisting only of alphanumerics, plus '-'
453 * and '.'. In that case, the action name and target value are
454 * separated by a double colon ("::"). For example:
455 * "app.action::target".
457 * The third format is used to represent an action with any type of
458 * target value, including strings. The target value follows the action
459 * name, surrounded in parens. For example: "app.action(42)". The
460 * target value is parsed using g_variant_parse(). If a tuple-typed
461 * value is desired, it must be specified in the same way, resulting in
462 * two sets of parens, for example: "app.action((1,2,3))". A string
463 * target can be specified this way as well: "app.action('target')".
464 * For strings, this third format must be used if * target value is
465 * empty or contains characters other than alphanumerics, '-' and '.'.
467 * Returns: %TRUE if successful, else %FALSE with @error set
472 g_action_parse_detailed_name (const gchar
*detailed_name
,
474 GVariant
**target_value
,
481 /* For historical (compatibility) reasons, this function accepts some
482 * cases of invalid action names as long as they don't interfere with
483 * the separation of the action from the target value.
485 * We decide which format we have based on which we see first between
489 if (*detailed_name
== '\0' || *detailed_name
== ' ')
492 base_len
= strcspn (detailed_name
, ": ()");
493 target
= detailed_name
+ base_len
;
494 target_len
= strlen (target
);
503 if (target
[1] != ':')
506 *target_value
= g_variant_ref_sink (g_variant_new_string (target
+ 2));
511 if (target
[target_len
- 1] != ')')
514 *target_value
= g_variant_parse (NULL
, target
+ 1, target
+ target_len
- 1, NULL
, error
);
515 if (*target_value
== NULL
)
521 *target_value
= NULL
;
525 *action_name
= g_strndup (detailed_name
, base_len
);
533 g_set_error (error
, G_VARIANT_PARSE_ERROR
, G_VARIANT_PARSE_ERROR_FAILED
,
534 "Detailed action name '%s' has invalid format", detailed_name
);
536 g_prefix_error (error
, "Detailed action name '%s' has invalid format: ", detailed_name
);
543 * g_action_print_detailed_name:
544 * @action_name: a valid action name
545 * @target_value: (nullable): a #GVariant target value, or %NULL
547 * Formats a detailed action name from @action_name and @target_value.
549 * It is an error to call this function with an invalid action name.
551 * This function is the opposite of g_action_parse_detailed_name().
552 * It will produce a string that can be parsed back to the @action_name
553 * and @target_value by that function.
555 * See that function for the types of strings that will be printed by
558 * Returns: a detailed format string
563 g_action_print_detailed_name (const gchar
*action_name
,
564 GVariant
*target_value
)
566 g_return_val_if_fail (g_action_name_is_valid (action_name
), NULL
);
568 if (target_value
== NULL
)
569 return g_strdup (action_name
);
571 if (g_variant_is_of_type (target_value
, G_VARIANT_TYPE_STRING
))
573 const gchar
*str
= g_variant_get_string (target_value
, NULL
);
575 if (g_action_name_is_valid (str
))
576 return g_strconcat (action_name
, "::", str
, NULL
);
580 GString
*result
= g_string_new (action_name
);
581 g_string_append_c (result
, '(');
582 g_variant_print_string (target_value
, result
, TRUE
);
583 g_string_append_c (result
, ')');
585 return g_string_free (result
, FALSE
);