atk/atkgobjectaccessible.c

   1 /* ATK - Accessibility Toolkit
   2  * Copyright 2001, 2002, 2003 Sun Microsystems Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include "config.h"
  21
  22 #include <atk/atkgobjectaccessible.h>
  23 #include <atk/atkregistry.h>
  24 #include <atk/atkutil.h>
  25
  26 /**
  27  * SECTION:atkgobjectaccessible
  28  * @Short_description: This object class is derived from AtkObject and
  29  *  can be used as a basis implementing accessible objects.
  30  * @Title:AtkGObjectAccessible
  31  *
  32  * This object class is derived from AtkObject. It can be used as a
  33  * basis for implementing accessible objects for GObjects which are
  34  * not derived from GtkWidget. One example of its use is in providing
  35  * an accessible object for GnomeCanvasItem in the GAIL library.
  36  */
  37 static void       atk_gobject_accessible_class_init       (AtkGObjectAccessibleClass   *klass);
  38 static void       atk_real_gobject_accessible_initialize  (AtkObject         *atk_obj,
  39                                                            gpointer          data);
  40 static void       atk_gobject_accessible_object_gone_cb   (gpointer          data);
  41
  42 static GQuark quark_accessible_object = 0;
  43 static GQuark quark_object = 0;
  44 static gpointer parent_class = NULL;
  45
  46 GType
  47 atk_gobject_accessible_get_type (void)
  48 {
  49   static GType type = 0;
  50
  51   if (!type)
  52     {
  53       static const GTypeInfo tinfo =
  54       {
  55         sizeof (AtkGObjectAccessibleClass),
  56         (GBaseInitFunc) NULL, /* base init */
  57         (GBaseFinalizeFunc) NULL, /* base finalize */
  58         (GClassInitFunc) atk_gobject_accessible_class_init,
  59         (GClassFinalizeFunc) NULL, /* class finalize */
  60         NULL, /* class data */
  61         sizeof (AtkGObjectAccessible),
  62         0, /* nb preallocs */
  63         (GInstanceInitFunc) NULL, /* instance init */
  64         NULL /* value table */
  65       };
  66
  67       type = g_type_register_static (ATK_TYPE_OBJECT,
  68                                      "AtkGObjectAccessible", &tinfo, 0);
  69     }
  70
  71   return type;
  72 }
  73
  74 /**
  75  * atk_gobject_accessible_for_object:
  76  * @obj: a #GObject
  77  *
  78  * Gets the accessible object for the specified @obj.
  79  *
  80  * Returns: (transfer none): a #AtkObject which is the accessible object for
  81  * the @obj
  82  **/
  83 AtkObject*
  84 atk_gobject_accessible_for_object (GObject *obj)
  85 {
  86   AtkObject* accessible;
  87
  88   g_return_val_if_fail (G_IS_OBJECT (obj), NULL);
  89   /* See if we have a cached accessible for this object */
  90
  91   accessible = quark_accessible_object ? g_object_get_qdata (obj, quark_accessible_object) : NULL;
  92
  93   if (!accessible)
  94     {
  95       AtkObjectFactory *factory;
  96       AtkRegistry *default_registry;
  97
  98       default_registry = atk_get_default_registry ();
  99       factory = atk_registry_get_factory (default_registry,
 100                                           G_OBJECT_TYPE (obj));
 101       accessible = atk_object_factory_create_accessible (factory,
 102                                                          obj);
 103       if (!ATK_IS_GOBJECT_ACCESSIBLE (accessible))
 104         {
 105           /*
 106            * The AtkObject which was created was not a AtkGObjectAccessible
 107            */
 108           g_object_weak_ref (obj,
 109                              (GWeakNotify) g_object_unref,
 110                              accessible);
 111           if (!quark_accessible_object)
 112             quark_accessible_object = g_quark_from_static_string ("accessible-object");
 113         }
 114       g_object_set_qdata (obj, quark_accessible_object, accessible);
 115     }
 116   return accessible;
 117 }
 118
 119 /**
 120  * atk_gobject_accessible_get_object:
 121  * @obj: a #AtkGObjectAccessible
 122  *
 123  * Gets the GObject for which @obj is the accessible object.
 124  *
 125  * Returns: (transfer none): a #GObject which is the object for which @obj is
 126  * the accessible object
 127  **/
 128 GObject *
 129 atk_gobject_accessible_get_object (AtkGObjectAccessible *obj)
 130 {
 131   g_return_val_if_fail (ATK_IS_GOBJECT_ACCESSIBLE (obj), NULL);
 132
 133   return g_object_get_qdata (G_OBJECT (obj), quark_object);
 134 }
 135
 136 static void
 137 atk_real_gobject_accessible_initialize (AtkObject  *atk_obj,
 138                                         gpointer   data)
 139 {
 140   AtkGObjectAccessible *atk_gobj;
 141
 142   atk_gobj = ATK_GOBJECT_ACCESSIBLE (atk_obj);
 143
 144   g_object_set_qdata (G_OBJECT (atk_gobj), quark_object, data);
 145   atk_obj->layer = ATK_LAYER_WIDGET;
 146
 147   g_object_weak_ref (data,
 148                      (GWeakNotify) atk_gobject_accessible_object_gone_cb,
 149                      atk_gobj);
 150 }
 151
 152 static void
 153 atk_gobject_accessible_object_gone_cb (gpointer  data)
 154 {
 155   GObject *object;
 156
 157   g_return_if_fail (ATK_IS_GOBJECT_ACCESSIBLE (data));
 158
 159   object = atk_gobject_accessible_get_object (data);
 160   if (object)
 161       g_object_set_qdata (object, quark_accessible_object, NULL);
 162
 163   g_object_set_qdata (G_OBJECT (data), quark_object, NULL);
 164   atk_object_notify_state_change (ATK_OBJECT (data), ATK_STATE_DEFUNCT,
 165                                   TRUE);
 166   g_object_unref (data);
 167 }
 168
 169 static void
 170 atk_gobject_accessible_dispose (GObject *atk_obj)
 171 {
 172    GObject *obj = atk_gobject_accessible_get_object (ATK_GOBJECT_ACCESSIBLE (atk_obj));
 173
 174    if (obj) {
 175       g_object_set_qdata (obj, quark_accessible_object, NULL);
 176       g_object_weak_unref (obj,
 177                            (GWeakNotify) atk_gobject_accessible_object_gone_cb,
 178                            atk_obj);
 179
 180       g_object_set_qdata (atk_obj, quark_object, NULL);
 181       atk_object_notify_state_change (ATK_OBJECT (atk_obj), ATK_STATE_DEFUNCT,
 182                                       TRUE);
 183    }
 184
 185    G_OBJECT_CLASS (parent_class)->dispose (atk_obj);
 186 }
 187
 188 static void
 189 atk_gobject_accessible_class_init (AtkGObjectAccessibleClass *klass)
 190 {
 191   AtkObjectClass *class;
 192   GObjectClass *object_class;
 193
 194   class = ATK_OBJECT_CLASS (klass);
 195
 196   parent_class = g_type_class_peek_parent (klass);
 197
 198   class->initialize = atk_real_gobject_accessible_initialize;
 199
 200   object_class = G_OBJECT_CLASS (klass);
 201   object_class->dispose = atk_gobject_accessible_dispose;
 202
 203   if (!quark_accessible_object)
 204     quark_accessible_object = g_quark_from_static_string ("accessible-object");
 205   quark_object = g_quark_from_static_string ("object-for-accessible");
 206 }