gtk2/gtk/gtkactionmuxerprivate.h
Christian Hergert ccac404f28 widget: fix class private data usage to be _init() safe
Before this commit, adding GtkWidgetAction to class private data would
require copying the actions to each subclass as they were built or
modified. This was convenient in that it is a sort of "copy on write"
semantic.

However, due to the way that GTypeInstance works with base _init()
functions, the "g_class" pointer in GTypeInstance is updated as each
_init() function is called. That means you cannot access the subclasses
class private data, but only the parent class private data.

If instead we use a singly linked list of GtkWidgetAction, each subclass
has their own "head" yet all subclasses share the tail of the
GtkWidgetAction chain.

This creates one bit of complexity though. You need a stable way to know
which "bit" is the "enabled" bit of the action so we can track enabled
GAction state. That is easily solved by calculating the distance to the
end of the chain for a given action so that base classes sort ahead of
subclasses. Since the parent class always knows its parent's actions, the
position is stable.

A new dynamic bitarray helper also helps us avoid allocations in all the
current cases (up to 64 actions per widget) and dynamically switches to
malloc if that is to ever be exceeded.
2020-03-20 11:17:56 -07:00

95 lines
4.3 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, see <http://www.gnu.org/licenses/>.
*
* Author: Ryan Lortie <desrt@desrt.ca>
*/
#ifndef __GTK_ACTION_MUXER_H__
#define __GTK_ACTION_MUXER_H__
#include <gio/gio.h>
#include "gtkwidget.h"
G_BEGIN_DECLS
#define GTK_TYPE_ACTION_MUXER (gtk_action_muxer_get_type ())
#define GTK_ACTION_MUXER(inst) (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
GTK_TYPE_ACTION_MUXER, GtkActionMuxer))
#define GTK_IS_ACTION_MUXER(inst) (G_TYPE_CHECK_INSTANCE_TYPE ((inst), \
GTK_TYPE_ACTION_MUXER))
typedef struct _GtkWidgetAction GtkWidgetAction;
typedef struct _GtkActionMuxer GtkActionMuxer;
struct _GtkWidgetAction
{
GtkWidgetAction *next;
char *name;
GType owner;
const GVariantType *parameter_type;
GtkWidgetActionActivateFunc activate;
const GVariantType *state_type;
GParamSpec *pspec;
};
GType gtk_action_muxer_get_type (void);
GtkActionMuxer * gtk_action_muxer_new (GtkWidget *widget);
void gtk_action_muxer_insert (GtkActionMuxer *muxer,
const gchar *prefix,
GActionGroup *action_group);
void gtk_action_muxer_remove (GtkActionMuxer *muxer,
const gchar *prefix);
GActionGroup * gtk_action_muxer_find (GtkActionMuxer *muxer,
const char *action_name,
const char **unprefixed_name);
GtkActionMuxer * gtk_action_muxer_get_parent (GtkActionMuxer *muxer);
void gtk_action_muxer_set_parent (GtkActionMuxer *muxer,
GtkActionMuxer *parent);
void gtk_action_muxer_set_primary_accel (GtkActionMuxer *muxer,
const gchar *action_and_target,
const gchar *primary_accel);
const gchar * gtk_action_muxer_get_primary_accel (GtkActionMuxer *muxer,
const gchar *action_and_target);
void
gtk_action_muxer_action_enabled_changed (GtkActionMuxer *muxer,
const char *action_name,
gboolean enabled);
void
gtk_action_muxer_action_state_changed (GtkActionMuxer *muxer,
const gchar *action_name,
GVariant *state);
/* No better place for these... */
gchar * gtk_print_action_and_target (const gchar *action_namespace,
const gchar *action_name,
GVariant *target);
gchar * gtk_normalise_detailed_action_name (const gchar *detailed_action_name);
G_END_DECLS
#endif /* __GTK_ACTION_MUXER_H__ */