glib/gio/gaction.h
Ryan Lortie 5ff65d8695 Make 4 incompatible changes to the GAction API
This commit represents an API break to GAction in the following ways:

  - the 'set_state' entry in the GActionInterface vtable has been
    renamed to 'change_state'.  The number and order of vtable items has
    not otherwise changed.

  - g_action_set_state() has been renamed to g_action_change_state() to
    match the updated vtable entry.

  - the "state" property of the GAction interface has been changed to
    read-only to reflect the fact that g_action_set_state() no longer
    exists.

  - GSimpleActionClass has been hidden.  GSimpleAction can no longer be
    subclassed.

>> Rationale

g_action_set_state() has never been a true setter in the sense that
calling it will update the value of the "state" property.  It has always
been closer to "request 'state' to be changed to this value" with
semantics defined by the implementor of the interface.  This is why the
equivalent method in GActionGroup had its name changed from 'set' to
'change'.  This change makes the two interfaces more consistent and
removes any implication about the effect that calling set_state() should
have on the 'state' property.

>> Impact

This incompatible API break was undertaken only because I strongly
suspect that it will go entirely unnoticed.  If the break actually
affects anybody, then we will accommodate them (possibly going as far as
to revert this commit entirely).

The virtual table change only impacts implementors of GAction.  I
strongly suspect that this is nobody (except for GSimpleAction).

The hiding of GSimpleActionClass only impacts impacts subclasses of
GSimpleAction.  I strongly suspect that none of these exist.

The changing of the property to be read-only only affects people who
were trying to change the state by using GObject properties.  I strongly
suspect that this is nobody at all.

The removal of the g_action_set_state() call is the most dangerous, but
I still suspect that it will impact nobody outside of GLib.  If anybody
is impacted by this change then, at their request, I will reintroduce
the API as a deprecated alias for g_action_change_state().
2011-06-29 11:38:21 +01:00

92 lines
4.3 KiB
C

/*
* Copyright © 2010 Codethink Limited
*
* This program 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.
*
* Authors: Ryan Lortie <desrt@desrt.ca>
*/
#if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
#error "Only <gio/gio.h> can be included directly."
#endif
#ifndef __G_ACTION_H__
#define __G_ACTION_H__
#include <gio/giotypes.h>
G_BEGIN_DECLS
#define G_TYPE_ACTION (g_action_get_type ())
#define G_ACTION(inst) (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
G_TYPE_ACTION, GAction))
#define G_IS_ACTION(inst) (G_TYPE_CHECK_INSTANCE_TYPE ((inst), G_TYPE_ACTION))
#define G_ACTION_GET_IFACE(inst) (G_TYPE_INSTANCE_GET_INTERFACE ((inst), \
G_TYPE_ACTION, GActionInterface))
typedef struct _GActionInterface GActionInterface;
/**
* GActionInterface:
* @get_name: the virtual function pointer for g_action_get_name()
* @get_parameter_type: the virtual function pointer for g_action_get_parameter_type()
* @get_state_type: the virtual function pointer for g_action_get_state_type()
* @get_state_hint: the virtual function pointer for g_action_get_state_hint()
* @get_enabled: the virtual function pointer for g_action_get_enabled()
* @get_state: the virtual function pointer for g_action_get_state()
* @change_state: the virtual function pointer for g_action_change_state()
* @activate: the virtual function pointer for g_action_activate(). Note that #GAction does not have an
* 'activate' signal but that implementations of it may have one.
*
* Since: 2.28
*/
struct _GActionInterface
{
GTypeInterface g_iface;
/* virtual functions */
const gchar * (* get_name) (GAction *action);
const GVariantType * (* get_parameter_type) (GAction *action);
const GVariantType * (* get_state_type) (GAction *action);
GVariant * (* get_state_hint) (GAction *action);
gboolean (* get_enabled) (GAction *action);
GVariant * (* get_state) (GAction *action);
void (* change_state) (GAction *action,
GVariant *value);
void (* activate) (GAction *action,
GVariant *parameter);
};
GType g_action_get_type (void) G_GNUC_CONST;
const gchar * g_action_get_name (GAction *action);
const GVariantType * g_action_get_parameter_type (GAction *action);
const GVariantType * g_action_get_state_type (GAction *action);
GVariant * g_action_get_state_hint (GAction *action);
gboolean g_action_get_enabled (GAction *action);
GVariant * g_action_get_state (GAction *action);
void g_action_change_state (GAction *action,
GVariant *value);
void g_action_activate (GAction *action,
GVariant *parameter);
G_END_DECLS
#endif /* __G_ACTION_H__ */