gtk2/gtk/gactionmuxer.c
Ryan Lortie e7ad2f97c8 add GActionMuxer and observer interfaces
These were destined for GLib, but they don't really make sense as a
public API.  Instead, we'll copy/paste them around between the various
codebases that need to render menus.
2011-12-19 12:51:08 -05:00

506 lines
15 KiB
C

/*
* 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Author: Ryan Lortie <desrt@desrt.ca>
*/
#include "config.h"
#include "gactionmuxer.h"
#include "gactionobservable.h"
#include "gactionobserver.h"
#include <string.h>
/**
* SECTION:gactionmuxer
* @short_description: Aggregate and monitor several action groups
*
* #GActionMuxer is a #GActionGroup and #GActionObservable that is
* capable of containing other #GActionGroup instances.
*
* The typical use is aggrgating all of the actions applicable to a
* particular context into a single action group, with namespacing.
*
* Consider the case of two action groups -- one containing actions
* applicable to an entire application (such as 'quit') and one
* containing actions applicable to a particular window in the
* application (such as 'fullscreen').
*
* In this case, each of these action groups could be added to a
* #GActionMuxer with the prefixes "app" and "win", respectively. This
* would expose the actions as "app.quit" and "win.fullscreen" on the
* #GActionGroup interface presented by the #GActionMuxer.
*
* Activations and state change requests on the #GActionMuxer are wired
* through to the underlying action group in the expected way.
*
* This class is typically only used at the site of "consumption" of
* actions (eg: when displaying a menu that contains many actions on
* different objects).
*
* Since: 2.32
**/
static void g_action_muxer_group_iface_init (GActionGroupInterface *iface);
static void g_action_muxer_observable_iface_init (GActionObservableInterface *iface);
typedef GObjectClass GActionMuxerClass;
struct _GActionMuxer
{
GObject parent_instance;
GHashTable *actions;
GHashTable *groups;
};
G_DEFINE_TYPE_WITH_CODE (GActionMuxer, g_action_muxer, G_TYPE_OBJECT,
G_IMPLEMENT_INTERFACE (G_TYPE_ACTION_GROUP, g_action_muxer_group_iface_init)
G_IMPLEMENT_INTERFACE (G_TYPE_ACTION_OBSERVABLE, g_action_muxer_observable_iface_init))
typedef struct
{
GActionMuxer *muxer;
GSList *watchers;
gchar *fullname;
} Action;
typedef struct
{
GActionMuxer *muxer;
GActionGroup *group;
gchar *prefix;
gulong handler_ids[4];
} Group;
static gchar **
g_action_muxer_list_actions (GActionGroup *action_group)
{
GActionMuxer *muxer = G_ACTION_MUXER (action_group);
return (gchar **) muxer->groups;
}
static Group *
g_action_muxer_find_group (GActionMuxer *muxer,
const gchar **name)
{
const gchar *dot;
gchar *prefix;
Group *group;
dot = strchr (*name, '.');
if (!dot)
return NULL;
prefix = g_strndup (*name, dot - *name);
group = g_hash_table_lookup (muxer->groups, prefix);
g_free (prefix);
*name = dot + 1;
return group;
}
static Action *
g_action_muxer_lookup_action (GActionMuxer *muxer,
const gchar *prefix,
const gchar *action_name,
gchar **fullname)
{
Action *action;
*fullname = g_strconcat (prefix, ".", action_name, NULL);
action = g_hash_table_lookup (muxer->actions, *fullname);
return action;
}
static void
g_action_muxer_action_enabled_changed (GActionGroup *action_group,
const gchar *action_name,
gboolean enabled,
gpointer user_data)
{
Group *group = user_data;
gchar *fullname;
Action *action;
GSList *node;
g_print ("feeling changes\n");
action = g_action_muxer_lookup_action (group->muxer, group->prefix, action_name, &fullname);
for (node = action ? action->watchers : NULL; node; node = node->next)
g_action_observer_action_enabled_changed (node->data, G_ACTION_OBSERVABLE (group->muxer), fullname, enabled);
g_action_group_action_enabled_changed (G_ACTION_GROUP (group->muxer), fullname, enabled);
g_free (fullname);
}
static void
g_action_muxer_action_state_changed (GActionGroup *action_group,
const gchar *action_name,
GVariant *state,
gpointer user_data)
{
Group *group = user_data;
gchar *fullname;
Action *action;
GSList *node;
action = g_action_muxer_lookup_action (group->muxer, group->prefix, action_name, &fullname);
for (node = action ? action->watchers : NULL; node; node = node->next)
g_action_observer_action_state_changed (node->data, G_ACTION_OBSERVABLE (group->muxer), fullname, state);
g_action_group_action_state_changed (G_ACTION_GROUP (group->muxer), fullname, state);
g_free (fullname);
}
static void
g_action_muxer_action_added (GActionGroup *action_group,
const gchar *action_name,
gpointer user_data)
{
const GVariantType *parameter_type;
Group *group = user_data;
gboolean enabled;
GVariant *state;
if (g_action_group_query_action (group->group, action_name, &enabled, &parameter_type, NULL, NULL, &state))
{
gchar *fullname;
Action *action;
GSList *node;
action = g_action_muxer_lookup_action (group->muxer, group->prefix, action_name, &fullname);
for (node = action ? action->watchers : NULL; node; node = node->next)
g_action_observer_action_added (node->data,
G_ACTION_OBSERVABLE (group->muxer),
fullname, parameter_type, enabled, state);
g_action_group_action_added (G_ACTION_GROUP (group->muxer), fullname);
if (state)
g_variant_unref (state);
g_free (fullname);
}
}
static void
g_action_muxer_action_removed (GActionGroup *action_group,
const gchar *action_name,
gpointer user_data)
{
Group *group = user_data;
gchar *fullname;
Action *action;
GSList *node;
action = g_action_muxer_lookup_action (group->muxer, group->prefix, action_name, &fullname);
for (node = action ? action->watchers : NULL; node; node = node->next)
g_action_observer_action_removed (node->data, G_ACTION_OBSERVABLE (group->muxer), fullname);
g_action_group_action_removed (G_ACTION_GROUP (group->muxer), fullname);
g_free (fullname);
}
static gboolean
g_action_muxer_query_action (GActionGroup *action_group,
const gchar *action_name,
gboolean *enabled,
const GVariantType **parameter_type,
const GVariantType **state_type,
GVariant **state_hint,
GVariant **state)
{
GActionMuxer *muxer = G_ACTION_MUXER (action_group);
Group *group;
group = g_action_muxer_find_group (muxer, &action_name);
if (!group)
return FALSE;
return g_action_group_query_action (group->group, action_name, enabled,
parameter_type, state_type, state_hint, state);
}
static void
g_action_muxer_activate_action (GActionGroup *action_group,
const gchar *action_name,
GVariant *parameter)
{
GActionMuxer *muxer = G_ACTION_MUXER (action_group);
Group *group;
group = g_action_muxer_find_group (muxer, &action_name);
if (group)
g_action_group_activate_action (group->group, action_name, parameter);
}
static void
g_action_muxer_change_action_state (GActionGroup *action_group,
const gchar *action_name,
GVariant *state)
{
GActionMuxer *muxer = G_ACTION_MUXER (action_group);
Group *group;
group = g_action_muxer_find_group (muxer, &action_name);
if (group)
g_action_group_change_action_state (group->group, action_name, state);
}
static void
g_action_muxer_unregister_internal (Action *action,
gpointer observer)
{
GActionMuxer *muxer = action->muxer;
GSList **ptr;
for (ptr = &action->watchers; *ptr; ptr = &(*ptr)->next)
if ((*ptr)->data == observer)
{
*ptr = g_slist_remove (*ptr, observer);
if (action->watchers == NULL)
{
g_hash_table_remove (muxer->actions, action->fullname);
g_free (action->fullname);
g_slice_free (Action, action);
g_object_unref (muxer);
}
break;
}
}
static void
g_action_muxer_weak_notify (gpointer data,
GObject *where_the_object_was)
{
Action *action = data;
g_action_muxer_unregister_internal (action, where_the_object_was);
}
static void
g_action_muxer_register_observer (GActionObservable *observable,
const gchar *name,
GActionObserver *observer)
{
GActionMuxer *muxer = G_ACTION_MUXER (observable);
Action *action;
action = g_hash_table_lookup (muxer->actions, name);
if (action == NULL)
{
action = g_slice_new (Action);
action->muxer = g_object_ref (muxer);
action->fullname = g_strdup (name);
action->watchers = NULL;
g_hash_table_insert (muxer->actions, action->fullname, action);
}
action->watchers = g_slist_prepend (action->watchers, observer);
g_object_weak_ref (G_OBJECT (observer), g_action_muxer_weak_notify, action);
}
static void
g_action_muxer_unregister_observer (GActionObservable *observable,
const gchar *name,
GActionObserver *observer)
{
GActionMuxer *muxer = G_ACTION_MUXER (observable);
Action *action;
action = g_hash_table_lookup (muxer->actions, name);
g_object_weak_unref (G_OBJECT (observer), g_action_muxer_weak_notify, action);
g_action_muxer_unregister_internal (action, observer);
}
static void
g_action_muxer_free_group (gpointer data)
{
Group *group = data;
g_object_unref (group->group);
g_free (group->prefix);
g_slice_free (Group, group);
}
static void
g_action_muxer_finalize (GObject *object)
{
GActionMuxer *muxer = G_ACTION_MUXER (object);
g_assert_cmpint (g_hash_table_size (muxer->actions), ==, 0);
g_hash_table_unref (muxer->actions);
g_hash_table_unref (muxer->groups);
G_OBJECT_CLASS (g_action_muxer_parent_class)
->finalize (object);
}
static void
g_action_muxer_init (GActionMuxer *muxer)
{
muxer->actions = g_hash_table_new (g_str_hash, g_str_equal);
muxer->groups = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, g_action_muxer_free_group);
}
static void
g_action_muxer_observable_iface_init (GActionObservableInterface *iface)
{
iface->register_observer = g_action_muxer_register_observer;
iface->unregister_observer = g_action_muxer_unregister_observer;
}
static void
g_action_muxer_group_iface_init (GActionGroupInterface *iface)
{
iface->list_actions = g_action_muxer_list_actions;
iface->query_action = g_action_muxer_query_action;
iface->activate_action = g_action_muxer_activate_action;
iface->change_action_state = g_action_muxer_change_action_state;
}
static void
g_action_muxer_class_init (GObjectClass *class)
{
class->finalize = g_action_muxer_finalize;
}
/**
* g_action_muxer_insert:
* @muxer: a #GActionMuxer
* @prefix: the prefix string for the action group
* @action_group: a #GActionGroup
*
* Adds the actions in @action_group to the list of actions provided by
* @muxer. @prefix is prefixed to each action name, such that for each
* action <varname>x</varname> in @action_group, there is an equivalent
* action @prefix<literal>.</literal><varname>x</varname> in @muxer.
*
* For example, if @prefix is "<literal>app</literal>" and @action_group
* contains an action called "<literal>quit</literal>", then @muxer will
* now contain an action called "<literal>app.quit</literal>".
*
* If any #GActionObservers are registered for actions in the group,
* "action_added" notifications will be emitted, as appropriate.
*
* @prefix must not contain a dot ('.').
*
* Since: 2.32
**/
void
g_action_muxer_insert (GActionMuxer *muxer,
const gchar *prefix,
GActionGroup *action_group)
{
gchar **actions;
Group *group;
gint i;
/* TODO: diff instead of ripout and replace */
g_action_muxer_remove (muxer, prefix);
group = g_slice_new (Group);
group->muxer = muxer;
group->group = g_object_ref (action_group);
group->prefix = g_strdup (prefix);
g_hash_table_insert (muxer->groups, group->prefix, group);
actions = g_action_group_list_actions (group->group);
for (i = 0; actions[i]; i++)
g_action_muxer_action_added (group->group, actions[i], group);
g_strfreev (actions);
group->handler_ids[0] = g_signal_connect (group->group, "action-added",
G_CALLBACK (g_action_muxer_action_added), group);
group->handler_ids[1] = g_signal_connect (group->group, "action-removed",
G_CALLBACK (g_action_muxer_action_removed), group);
group->handler_ids[2] = g_signal_connect (group->group, "action-enabled-changed",
G_CALLBACK (g_action_muxer_action_enabled_changed), group);
group->handler_ids[3] = g_signal_connect (group->group, "action-state-changed",
G_CALLBACK (g_action_muxer_action_state_changed), group);
}
/**
* g_action_muxer_remove:
* @muxer: a #GActionMuxer
* @prefix: the prefix of the action group to remove
*
* Removes a #GActionGroup from the #GActionMuxer.
*
* If any #GActionObservers are registered for actions in the group,
* "action_removed" notifications will be emitted, as appropriate.
*
* Since: 2.32
**/
void
g_action_muxer_remove (GActionMuxer *muxer,
const gchar *prefix)
{
Group *group;
group = g_hash_table_lookup (muxer->groups, prefix);
if (group != NULL)
{
gchar **actions;
gint i;
g_hash_table_steal (muxer->groups, prefix);
actions = g_action_group_list_actions (group->group);
for (i = 0; actions[i]; i++)
g_action_muxer_action_removed (group->group, actions[i], group);
g_strfreev (actions);
/* 'for loop' or 'four loop'? */
for (i = 0; i < 4; i++)
g_signal_handler_disconnect (group->group, group->handler_ids[i]);
g_action_muxer_free_group (group);
}
}
/**
* g_action_muxer_new:
*
* Creates a new #GActionMuxer.
*
* Since: 2.32
**/
GActionMuxer *
g_action_muxer_new (void)
{
return g_object_new (G_TYPE_ACTION_MUXER, NULL);
}