/*
* AT-SPI - Assistive Technology Service Provider Interface
* (Gnome Accessibility Project; http://developer.gnome.org/projects/gap)
*
* Copyright 2008 Novell, Inc.
* Copyright 2008, 2009, 2010 Codethink Ltd.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library 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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "bridge.h"
#include "accessible-register.h"
/*
* This module is responsible for keeping track of all the AtkObjects in
* the application, so that they can be accessed remotely and placed in
* a client side cache.
*
* To access an AtkObject remotely we need to provide a D-Bus object
* path for it. The D-Bus object paths used have a standard prefix
* (SPI_ATK_OBJECT_PATH_PREFIX). Appended to this prefix is a string
* representation of an integer reference. So to access an AtkObject
* remotely we keep a Hashtable that maps the given reference to
* the AtkObject pointer. An object in this hash table is said to be 'registered'.
*
* The architecture of AT-SPI dbus is such that AtkObjects are not
* remotely reference counted. This means that we need to keep track of
* object destruction. When an object is destroyed it must be 'deregistered'
* To do this lookup we keep a dbus-id attribute on each AtkObject.
*
*/
#define SPI_ATK_PATH_PREFIX_LENGTH 27
#define SPI_ATK_OBJECT_PATH_PREFIX "/org/a11y/atspi/accessible/"
#define SPI_ATK_OBJECT_PATH_ROOT "root"
#define SPI_ATK_OBJECT_REFERENCE_TEMPLATE SPI_ATK_OBJECT_PATH_PREFIX "%d"
#define SPI_DBUS_ID "spi-dbus-id"
SpiRegister *spi_global_register = NULL;
static const gchar * spi_register_root_path = SPI_ATK_OBJECT_PATH_PREFIX SPI_ATK_OBJECT_PATH_ROOT;
enum
{
OBJECT_REGISTERED,
OBJECT_DEREGISTERED,
LAST_SIGNAL
};
static guint register_signals[LAST_SIGNAL] = { 0 };
/*---------------------------------------------------------------------------*/
static void
spi_register_finalize (GObject * object);
/*---------------------------------------------------------------------------*/
G_DEFINE_TYPE (SpiRegister, spi_register, G_TYPE_OBJECT)
static void spi_register_class_init (SpiRegisterClass * klass)
{
GObjectClass *object_class = (GObjectClass *) klass;
spi_register_parent_class = g_type_class_ref (G_TYPE_OBJECT);
object_class->finalize = spi_register_finalize;
register_signals [OBJECT_REGISTERED] =
g_signal_new ("object-registered",
SPI_REGISTER_TYPE,
G_SIGNAL_ACTION,
0,
NULL,
NULL,
g_cclosure_marshal_VOID__OBJECT,
G_TYPE_NONE,
1,
G_TYPE_OBJECT);
register_signals [OBJECT_DEREGISTERED] =
g_signal_new ("object-deregistered",
SPI_REGISTER_TYPE,
G_SIGNAL_ACTION,
0,
NULL,
NULL,
g_cclosure_marshal_VOID__OBJECT,
G_TYPE_NONE,
1,
G_TYPE_OBJECT);
}
static void
spi_register_init (SpiRegister * reg)
{
reg->ref2ptr = g_hash_table_new (g_direct_hash, g_direct_equal);
reg->reference_counter = 0;
}
static void
deregister_object (gpointer data, GObject * gobj)
{
SpiRegister *reg = SPI_REGISTER (data);
spi_register_deregister_object (reg, gobj, FALSE);
}
static void
spi_register_remove_weak_ref (gpointer key, gpointer val, gpointer reg)
{
g_object_weak_unref (val, deregister_object, reg);
}
static void
spi_register_finalize (GObject * object)
{
SpiRegister *reg = SPI_REGISTER (object);
g_hash_table_foreach (reg->ref2ptr, spi_register_remove_weak_ref, reg);
g_hash_table_unref (reg->ref2ptr);
G_OBJECT_CLASS (spi_register_parent_class)->finalize (object);
}
/*---------------------------------------------------------------------------*/
/*
* Each AtkObject must be asssigned a D-Bus path (Reference)
*
* This function provides an integer reference for a new
* AtkObject.
*
* TODO: Make this reference a little more unique, this is shoddy.
*/
static guint
assign_reference (SpiRegister * reg)
{
reg->reference_counter++;
/* Reference of 0 not allowed as used as direct key in hash table */
if (reg->reference_counter == 0)
reg->reference_counter++;
return reg->reference_counter;
}
/*---------------------------------------------------------------------------*/
/*
* Returns the reference of the object, or 0 if it is not registered.
*/
static guint
object_to_ref (GObject * gobj)
{
return GPOINTER_TO_INT (g_object_get_data (gobj, SPI_DBUS_ID));
}
/*
* Converts the Accessible object reference to its D-Bus object path
*/
static gchar *
ref_to_path (guint ref)
{
return g_strdup_printf (SPI_ATK_OBJECT_REFERENCE_TEMPLATE, ref);
}
/*---------------------------------------------------------------------------*/
/*
* Callback for when a registered AtkObject is destroyed.
*
* Removes the AtkObject from the reference lookup tables, meaning
* it is no longer exposed over D-Bus.
*/
void
spi_register_deregister_object (SpiRegister *reg, GObject *gobj, gboolean unref)
{
guint ref;
ref = object_to_ref (gobj);
if (ref != 0)
{
g_signal_emit (reg,
register_signals [OBJECT_DEREGISTERED],
0,
gobj);
if (unref)
g_object_weak_unref (gobj, deregister_object, reg);
g_hash_table_remove (reg->ref2ptr, GINT_TO_POINTER (ref));
#ifdef SPI_ATK_DEBUG
g_debug ("DEREG - %d", ref);
#endif
}
}
static void
register_object (SpiRegister * reg, GObject * gobj)
{
guint ref;
g_return_if_fail (G_IS_OBJECT (gobj));
ref = assign_reference (reg);
g_hash_table_insert (reg->ref2ptr, GINT_TO_POINTER (ref), gobj);
g_object_set_data (G_OBJECT (gobj), SPI_DBUS_ID, GINT_TO_POINTER (ref));
g_object_weak_ref (G_OBJECT (gobj), deregister_object, reg);
#ifdef SPI_ATK_DEBUG
g_debug ("REG - %d", ref);
#endif
g_signal_emit (reg, register_signals [OBJECT_REGISTERED], 0, gobj);
}
/*---------------------------------------------------------------------------*/
/*
* Used to lookup an GObject from its D-Bus path.
*
* If the D-Bus path is not found this function returns NULL.
*/
GObject *
spi_register_path_to_object (SpiRegister * reg, const char *path)
{
guint index;
void *data;
g_return_val_if_fail (path, NULL);
if (strncmp (path, SPI_ATK_OBJECT_PATH_PREFIX, SPI_ATK_PATH_PREFIX_LENGTH)
!= 0)
return NULL;
path += SPI_ATK_PATH_PREFIX_LENGTH; /* Skip over the prefix */
/* Map the root path to the root object. */
if (!g_strcmp0 (SPI_ATK_OBJECT_PATH_ROOT, path))
return G_OBJECT (spi_global_app_data->root);
index = atoi (path);
data = g_hash_table_lookup (reg->ref2ptr, GINT_TO_POINTER (index));
if (data)
return G_OBJECT(data);
else
return NULL;
}
GObject *
spi_global_register_path_to_object (const char * path)
{
return spi_register_path_to_object (spi_global_register, path);
}
/*
* Used to lookup a D-Bus path from the GObject.
*
* If the objects is not already registered,
* this function will register it.
*/
gchar *
spi_register_object_to_path (SpiRegister * reg, GObject * gobj)
{
guint ref;
if (gobj == NULL)
return NULL;
/* Map the root object to the root path. */
if ((void *)gobj == (void *)spi_global_app_data->root)
return g_strdup (spi_register_root_path);
ref = object_to_ref (gobj);
if (!ref)
{
register_object (reg, gobj);
ref = object_to_ref (gobj);
}
if (!ref)
return NULL;
else
return ref_to_path (ref);
}
guint
spi_register_object_to_ref (GObject * gobj)
{
return object_to_ref (gobj);
}
/*
* Gets the path that indicates the accessible desktop object.
* This object is logically located on the registry daemon and not
* within any particular application.
*/
gchar *
spi_register_root_object_path ()
{
return g_strdup (SPI_ATK_OBJECT_PATH_PREFIX SPI_ATK_OBJECT_PATH_ROOT);
}
/*END------------------------------------------------------------------------*/