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, write to the
16 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
17 * Boston, MA 02111-1307, USA.
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
54 * #GSimpleAction and #GtkAction.
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 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.
69 * @get_name: the virtual function pointer for g_action_get_name()
70 * @get_parameter_type: the virtual function pointer for g_action_get_parameter_type()
71 * @get_state_type: the virtual function pointer for g_action_get_state_type()
72 * @get_state_hint: the virtual function pointer for g_action_get_state_hint()
73 * @get_enabled: the virtual function pointer for g_action_get_enabled()
74 * @get_state: the virtual function pointer for g_action_get_state()
75 * @change_state: the virtual function pointer for g_action_change_state()
76 * @activate: the virtual function pointer for g_action_activate(). Note that #GAction does not have an
77 * 'activate' signal but that implementations of it may have one.
79 * The virtual function table for #GAction.
85 g_action_default_init (GActionInterface *iface)
90 * The name of the action. This is mostly meaningful for identifying
91 * the action once it has been added to a #GActionGroup.
95 g_object_interface_install_property (iface,
96 g_param_spec_string ("name",
98 P_("The name used to invoke the action"),
101 G_PARAM_STATIC_STRINGS));
104 * GAction:parameter-type:
106 * The type of the parameter that must be given when activating the
111 g_object_interface_install_property (iface,
112 g_param_spec_boxed ("parameter-type",
113 P_("Parameter Type"),
114 P_("The type of GVariant passed to activate()"),
117 G_PARAM_STATIC_STRINGS));
122 * If @action is currently enabled.
124 * If the action is disabled then calls to g_action_activate() and
125 * g_action_change_state() have no effect.
129 g_object_interface_install_property (iface,
130 g_param_spec_boolean ("enabled",
132 P_("If the action can be activated"),
135 G_PARAM_STATIC_STRINGS));
138 * GAction:state-type:
140 * The #GVariantType of the state that the action has, or %NULL if the
141 * action is stateless.
145 g_object_interface_install_property (iface,
146 g_param_spec_boxed ("state-type",
148 P_("The type of the state kept by the action"),
151 G_PARAM_STATIC_STRINGS));
156 * The state of the action, or %NULL if the action is stateless.
160 g_object_interface_install_property (iface,
161 g_param_spec_variant ("state",
163 P_("The state the action is in"),
167 G_PARAM_STATIC_STRINGS));
171 * g_action_change_state:
172 * @action: a #GAction
173 * @value: the new state
175 * Request for the state of @action to be changed to @value.
177 * The action must be stateful and @value must be of the correct type.
178 * See g_action_get_state_type().
180 * This call merely requests a change. The action may refuse to change
181 * its state or may change its state to something other than @value.
182 * See g_action_get_state_hint().
184 * If the @value GVariant is floating, it is consumed.
189 g_action_change_state (GAction *action,
192 const GVariantType *state_type;
194 g_return_if_fail (G_IS_ACTION (action));
195 g_return_if_fail (value != NULL);
196 state_type = g_action_get_state_type (action);
197 g_return_if_fail (state_type != NULL);
198 g_return_if_fail (g_variant_is_of_type (value, state_type));
200 g_variant_ref_sink (value);
202 G_ACTION_GET_IFACE (action)
203 ->change_state (action, value);
205 g_variant_unref (value);
209 * g_action_get_state:
210 * @action: a #GAction
212 * Queries the current state of @action.
214 * If the action is not stateful then %NULL will be returned. If the
215 * action is stateful then the type of the return value is the type
216 * given by g_action_get_state_type().
218 * The return value (if non-%NULL) should be freed with
219 * g_variant_unref() when it is no longer required.
221 * Returns: (transfer full): the current state of the action
226 g_action_get_state (GAction *action)
228 g_return_val_if_fail (G_IS_ACTION (action), NULL);
230 return G_ACTION_GET_IFACE (action)
231 ->get_state (action);
236 * @action: a #GAction
238 * Queries the name of @action.
240 * Returns: the name of the action
245 g_action_get_name (GAction *action)
247 g_return_val_if_fail (G_IS_ACTION (action), NULL);
249 return G_ACTION_GET_IFACE (action)
254 * g_action_get_parameter_type:
255 * @action: a #GAction
257 * Queries the type of the parameter that must be given when activating
260 * When activating the action using g_action_activate(), the #GVariant
261 * given to that function must be of the type returned by this function.
263 * In the case that this function returns %NULL, you must not give any
264 * #GVariant, but %NULL instead.
266 * Returns: (allow-none): the parameter type
271 g_action_get_parameter_type (GAction *action)
273 g_return_val_if_fail (G_IS_ACTION (action), NULL);
275 return G_ACTION_GET_IFACE (action)
276 ->get_parameter_type (action);
280 * g_action_get_state_type:
281 * @action: a #GAction
283 * Queries the type of the state of @action.
285 * If the action is stateful (e.g. created with
286 * g_simple_action_new_stateful()) then this function returns the
287 * #GVariantType of the state. This is the type of the initial value
288 * given as the state. All calls to g_action_change_state() must give a
289 * #GVariant of this type and g_action_get_state() will return a
290 * #GVariant of the same type.
292 * If the action is not stateful (e.g. created with g_simple_action_new())
293 * then this function will return %NULL. In that case, g_action_get_state()
294 * will return %NULL and you must not call g_action_change_state().
296 * Returns: (allow-none): the state type, if the action is stateful
301 g_action_get_state_type (GAction *action)
303 g_return_val_if_fail (G_IS_ACTION (action), NULL);
305 return G_ACTION_GET_IFACE (action)
306 ->get_state_type (action);
310 * g_action_get_state_hint:
311 * @action: a #GAction
313 * Requests a hint about the valid range of values for the state of
316 * If %NULL is returned it either means that the action is not stateful
317 * or that there is no hint about the valid range of values for the
318 * state of the action.
320 * If a #GVariant array is returned then each item in the array is a
321 * possible value for the state. If a #GVariant pair (ie: two-tuple) is
322 * returned then the tuple specifies the inclusive lower and upper bound
323 * of valid values for the state.
325 * In any case, the information is merely a hint. It may be possible to
326 * have a state value outside of the hinted range and setting a value
327 * within the range may fail.
329 * The return value (if non-%NULL) should be freed with
330 * g_variant_unref() when it is no longer required.
332 * Returns: (transfer full): the state range hint
337 g_action_get_state_hint (GAction *action)
339 g_return_val_if_fail (G_IS_ACTION (action), NULL);
341 return G_ACTION_GET_IFACE (action)
342 ->get_state_hint (action);
346 * g_action_get_enabled:
347 * @action: a #GAction
349 * Checks if @action is currently enabled.
351 * An action must be enabled in order to be activated or in order to
352 * have its state changed from outside callers.
354 * Returns: whether the action is enabled
359 g_action_get_enabled (GAction *action)
361 g_return_val_if_fail (G_IS_ACTION (action), FALSE);
363 return G_ACTION_GET_IFACE (action)
364 ->get_enabled (action);
369 * @action: a #GAction
370 * @parameter: (allow-none): the parameter to the activation
372 * Activates the action.
374 * @parameter must be the correct type of parameter for the action (ie:
375 * the parameter type given at construction time). If the parameter
376 * type was %NULL then @parameter must also be %NULL.
378 * If the @parameter GVariant is floating, it is consumed.
383 g_action_activate (GAction *action,
386 g_return_if_fail (G_IS_ACTION (action));
388 if (parameter != NULL)
389 g_variant_ref_sink (parameter);
391 G_ACTION_GET_IFACE (action)
392 ->activate (action, parameter);
394 if (parameter != NULL)
395 g_variant_unref (parameter);
399 * g_action_name_is_valid:
400 * @action_name: an potential action name
402 * Checks if @action_name is valid.
404 * @action_name is valid if it consists only of alphanumeric characters,
405 * plus '-' and '.'. The empty string is not a valid action name.
407 * It is an error to call this function with a non-utf8 @action_name.
408 * @action_name must not be %NULL.
410 * Returns: %TRUE if @action_name is valid
415 g_action_name_is_valid (const gchar *action_name)
420 g_return_val_if_fail (action_name != NULL, FALSE);
422 for (i = 0; (c = action_name[i]); i++)
423 if (!g_ascii_isalnum (c) && c != '.' && c != '-')
430 * g_action_parse_detailed_name:
431 * @detailed_name: a detailed action name
432 * @action_name: (out): the action name
433 * @target_value: (out): the target value, or %NULL for no target
434 * @error: a pointer to a %NULL #GError, or %NULL
436 * Parses a detailed action name into its separate name and target
439 * Detailed action names can have three formats.
441 * The first format is used to represent an action name with no target
442 * value and consists of just an action name containing no whitespace
443 * nor the characters ':', '(' or ')'. For example: "app.action".
445 * The second format is used to represent an action with a target value
446 * that is a non-empty string consisting only of alphanumerics, plus '-'
447 * and '.'. In that case, the action name and target value are
448 * separated by a double colon ("::"). For example:
449 * "app.action::target".
451 * The third format is used to represent an action with any type of
452 * target value, including strings. The target value follows the action
453 * name, surrounded in parens. For example: "app.action(42)". The
454 * target value is parsed using g_variant_parse(). If a tuple-typed
455 * value is desired, it must be specified in the same way, resulting in
456 * two sets of parens, for example: "app.action((1,2,3))". A string
457 * target can be specified this way as well: "app.action('target')".
458 * For strings, this third format must be used if * target value is
459 * empty or contains characters other than alphanumerics, '-' and '.'.
461 * Returns: %TRUE if successful, else %FALSE with @error set
466 g_action_parse_detailed_name (const gchar *detailed_name,
468 GVariant **target_value,
475 /* For historical (compatibility) reasons, this function accepts some
476 * cases of invalid action names as long as they don't interfere with
477 * the separation of the action from the target value.
479 * We decide which format we have based on which we see first between
483 if (*detailed_name == '\0' || *detailed_name == ' ')
486 base_len = strcspn (detailed_name, ": ()");
487 target = detailed_name + base_len;
488 target_len = strlen (target);
497 if (target[1] != ':')
500 *target_value = g_variant_ref_sink (g_variant_new_string (target + 2));
505 if (target[target_len - 1] != ')')
508 *target_value = g_variant_parse (NULL, target + 1, target + target_len - 1, NULL, error);
509 if (*target_value == NULL)
515 *target_value = NULL;
519 *action_name = g_strndup (detailed_name, base_len);
527 g_set_error (error, G_VARIANT_PARSE_ERROR, G_VARIANT_PARSE_ERROR_FAILED,
528 "Detailed action name '%s' has invalid format", detailed_name);
530 g_prefix_error (error, "Detailed action name '%s' has invalid format: ", detailed_name);
537 * g_action_print_detailed_name:
538 * @action_name: a valid action name
539 * @target_value: (allow-none): a #GVariant target value, or %NULL
541 * Formats a detailed action name from @action_name and @target_value.
543 * It is an error to call this function with an invalid action name.
545 * This function is the opposite of
546 * g_action_parse_detailed_action_name(). It will produce a string that
547 * can be parsed back to the @action_name and @target_value by that
550 * See that function for the types of strings that will be printed by
553 * Returns: a detailed format string
558 g_action_print_detailed_name (const gchar *action_name,
559 GVariant *target_value)
561 g_return_val_if_fail (g_action_name_is_valid (action_name), NULL);
563 if (target_value == NULL)
564 return g_strdup (action_name);
566 if (g_variant_is_of_type (target_value, G_VARIANT_TYPE_STRING))
568 const gchar *str = g_variant_get_string (target_value, NULL);
570 if (g_action_name_is_valid (str))
571 return g_strconcat (action_name, "::", str, NULL);
575 GString *result = g_string_new (action_name);
576 g_string_append_c (result, '(');
577 g_variant_print_string (target_value, result, TRUE);
578 g_string_append_c (result, ')');
580 return g_string_free (result, FALSE);