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/*
* Copyright © 2011 Canonical Limited
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2 of the
* licence or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
* Authors: Ryan Lortie <desrt@desrt.ca>
*/
#include "config.h"
#include "gactionobserver.h"
G_DEFINE_INTERFACE (GActionObserver, g_action_observer, G_TYPE_OBJECT)
/**
* SECTION:gactionobserver
* @short_description: an interface implemented by objects that are
* interested in monitoring actions for changes
*
* GActionObserver is a simple interface allowing objects that wish to
* be notified of changes to actions to be notified of those changes.
*
* It is also possible to monitor changes to action groups using
* #GObject signals, but there are a number of reasons that this
* approach could become problematic:
*
* - there are four separate signals that must be manually connected
* and disconnected
*
* - when a large number of different observers wish to monitor a
* (usually disjoint) set of actions within the same action group,
* there is only one way to avoid having all notifications delivered
* to all observers: signal detail. In order to use signal detail,
* each action name must be quarked, which is not always practical.
*
* - even if quarking is acceptable, #GObject signal details are
* implemented by scanning a linked list, so there is no real
* decrease in complexity
*/
void
g_action_observer_default_init (GActionObserverInterface *class)
{
}
/*
* g_action_observer_action_added:
* @observer: a #GActionObserver
* @observable: the source of the event
* @action_name: the name of the action
* @enabled: %TRUE if the action is now enabled
* @parameter_type: the parameter type for action invocations, or %NULL
* if no parameter is required
* @state: the current state of the action, or %NULL if the action is
* stateless
*
* This function is called when an action that the observer is
* registered to receive events for is added.
*
* This function should only be called by objects with which the
* observer has explicitly registered itself to receive events.
*/
void
g_action_observer_action_added (GActionObserver *observer,
GActionObservable *observable,
const gchar *action_name,
const GVariantType *parameter_type,
gboolean enabled,
GVariant *state)
{
g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
G_ACTION_OBSERVER_GET_IFACE (observer)
->action_added (observer, observable, action_name, parameter_type, enabled, state);
}
/*
* g_action_observer_action_enabled_changed:
* @observer: a #GActionObserver
* @observable: the source of the event
* @action_name: the name of the action
* @enabled: %TRUE if the action is now enabled
*
* This function is called when an action that the observer is
* registered to receive events for becomes enabled or disabled.
*
* This function should only be called by objects with which the
* observer has explicitly registered itself to receive events.
*/
void
g_action_observer_action_enabled_changed (GActionObserver *observer,
GActionObservable *observable,
const gchar *action_name,
gboolean enabled)
{
g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
G_ACTION_OBSERVER_GET_IFACE (observer)
->action_enabled_changed (observer, observable, action_name, enabled);
}
/*
* g_action_observer_action_state_changed:
* @observer: a #GActionObserver
* @observable: the source of the event
* @action_name: the name of the action
* @state: the new state of the action
*
* This function is called when an action that the observer is
* registered to receive events for changes to its state.
*
* This function should only be called by objects with which the
* observer has explicitly registered itself to receive events.
*/
void
g_action_observer_action_state_changed (GActionObserver *observer,
GActionObservable *observable,
const gchar *action_name,
GVariant *state)
{
g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
G_ACTION_OBSERVER_GET_IFACE (observer)
->action_state_changed (observer, observable, action_name, state);
}
/*
* g_action_observer_action_removed:
* @observer: a #GActionObserver
* @observable: the source of the event
* @action_name: the name of the action
*
* This function is called when an action that the observer is
* registered to receive events for is removed.
*
* This function should only be called by objects with which the
* observer has explicitly registered itself to receive events.
*/
void
g_action_observer_action_removed (GActionObserver *observer,
GActionObservable *observable,
const gchar *action_name)
{
g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
G_ACTION_OBSERVER_GET_IFACE (observer)
->action_removed (observer, observable, action_name);
}
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