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* Copyright © 2011 Canonical Limited
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* licence or (at your option) any later version.
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307,
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* Authors: Ryan Lortie <desrt@desrt.ca>
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#include "gactionobserver.h"
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G_DEFINE_INTERFACE (GActionObserver, g_action_observer, G_TYPE_OBJECT)
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* SECTION:gactionobserver
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* @short_description: an interface implemented by objects that are
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* interested in monitoring actions for changes
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* GActionObserver is a simple interface allowing objects that wish to
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* be notified of changes to actions to be notified of those changes.
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* It is also possible to monitor changes to action groups using
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* #GObject signals, but there are a number of reasons that this
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* approach could become problematic:
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* - there are four separate signals that must be manually connected
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* - when a large number of different observers wish to monitor a
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* (usually disjoint) set of actions within the same action group,
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* there is only one way to avoid having all notifications delivered
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* to all observers: signal detail. In order to use signal detail,
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* each action name must be quarked, which is not always practical.
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* - even if quarking is acceptable, #GObject signal details are
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* implemented by scanning a linked list, so there is no real
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* decrease in complexity
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g_action_observer_default_init (GActionObserverInterface *class)
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* g_action_observer_action_added:
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* @observer: a #GActionObserver
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* @observable: the source of the event
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* @action_name: the name of the action
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* @enabled: %TRUE if the action is now enabled
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* @parameter_type: the parameter type for action invocations, or %NULL
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* if no parameter is required
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* @state: the current state of the action, or %NULL if the action is
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* This function is called when an action that the observer is
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* registered to receive events for is added.
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* This function should only be called by objects with which the
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* observer has explicitly registered itself to receive events.
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g_action_observer_action_added (GActionObserver *observer,
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GActionObservable *observable,
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const gchar *action_name,
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const GVariantType *parameter_type,
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g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
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G_ACTION_OBSERVER_GET_IFACE (observer)
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->action_added (observer, observable, action_name, parameter_type, enabled, state);
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* g_action_observer_action_enabled_changed:
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* @observer: a #GActionObserver
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* @observable: the source of the event
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* @action_name: the name of the action
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* @enabled: %TRUE if the action is now enabled
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* This function is called when an action that the observer is
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* registered to receive events for becomes enabled or disabled.
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* This function should only be called by objects with which the
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* observer has explicitly registered itself to receive events.
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g_action_observer_action_enabled_changed (GActionObserver *observer,
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GActionObservable *observable,
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const gchar *action_name,
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g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
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G_ACTION_OBSERVER_GET_IFACE (observer)
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->action_enabled_changed (observer, observable, action_name, enabled);
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* g_action_observer_action_state_changed:
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* @observer: a #GActionObserver
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* @observable: the source of the event
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* @action_name: the name of the action
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* @state: the new state of the action
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* This function is called when an action that the observer is
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* registered to receive events for changes its state.
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* This function should only be called by objects with which the
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* observer has explicitly registered itself to receive events.
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g_action_observer_action_state_changed (GActionObserver *observer,
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GActionObservable *observable,
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const gchar *action_name,
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g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
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G_ACTION_OBSERVER_GET_IFACE (observer)
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->action_state_changed (observer, observable, action_name, state);
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* g_action_observer_action_removed:
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* @observer: a #GActionObserver
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* @observable: the source of the event
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* @action_name: the name of the action
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* This function is called when an action that the observer is
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* registered to receive events for is removed.
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* This function should only be called by objects with which the
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* observer has explicitly registered itself to receive events.
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g_action_observer_action_removed (GActionObserver *observer,
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GActionObservable *observable,
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const gchar *action_name)
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g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
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G_ACTION_OBSERVER_GET_IFACE (observer)
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->action_removed (observer, observable, action_name);
added
removed
src/gactionobserver.c
