#include "bridge.h"
#include "accessible-register.h"
-/* TODO
- * Need to add concurrency support.
- */
-
-#define ATK_BRIDGE_OBJECT_PATH_PREFIX "/org/freedesktop/atspi/accessible"
-#define ATK_BRIDGE_OBJECT_REFERENCE_TEMPLATE ATK_BRIDGE_OBJECT_PATH_PREFIX "/%d"
-#define ATK_BRIDGE_PATH_PREFIX_LENGTH 33
-
/*
* This module is responsible for keeping track of all the AtkObjects in
* the application, so that they can be accessed remotely and placed in
*
* 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
- * (ATK_BRIDGE_OBJECT_PATH_PREFIX). Appended to this prefix is a string
+ * (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'.
* In addition to accessing the objects remotely we must be able to update
* the client side cache. This is done using the 'update' signal of the
* org.freedesktop.atspi.Tree interface. The update signal should send out
- * all of the cacheable data for each AtkObject that has changed since the
- * last update. It should also provide a list of objects that have been
- * removed since the last update.
+ * all of the cacheable data for an Accessible object.
+ *
+ */
+
+/*
+ * FIXME
+ *
+ * This code seems very brittle.
+ * I would prefer changes to be made to
+ * gail and the ATK interface so that all Accessible
+ * objects are registered with an exporting module.
+ *
+ * This is the same system as Qt has with the QAccessibleBridge
+ * and QAccessibleBridgePlugin. It entails some rather
+ * large structural changes to ATK though:
+ *
+ * Removing infinite spaces (Child access no longer references child).
+ * Removing lazy creation of accessible objects.
*/
-GHashTable *ref2ptr = NULL; /* Used for converting a D-Bus path (Reference) to the object pointer */
+#define SPI_ATK_OBJECT_PATH_PREFIX "/org/freedesktop/atspi/accessible"
+#define SPI_ATK_OBJECT_PATH_DESKTOP "/root"
+
+#define SPI_ATK_PATH_PREFIX_LENGTH 33
+#define SPI_ATK_OBJECT_REFERENCE_TEMPLATE SPI_ATK_OBJECT_PATH_PREFIX "/%d"
+
+
+static GHashTable *ref2ptr = NULL; /* Used for converting a D-Bus path (Reference) to the object pointer */
static guint counter = 1;
+static GStaticRecMutex registration_mutex = G_STATIC_REC_MUTEX_INIT;
+
+/*---------------------------------------------------------------------------*/
+
+static GStaticMutex recursion_check_guard = G_STATIC_MUTEX_INIT;
+static gboolean recursion_check = FALSE;
+
+static gboolean
+recursion_check_and_set ()
+{
+ gboolean ret;
+ g_static_mutex_lock (&recursion_check_guard);
+ ret = recursion_check;
+ recursion_check = TRUE;
+ g_static_mutex_unlock (&recursion_check_guard);
+ return ret;
+}
+
+static void
+recursion_check_unset ()
+{
+ g_static_mutex_lock (&recursion_check_guard);
+ recursion_check = FALSE;
+ g_static_mutex_unlock (&recursion_check_guard);
+}
+
/*---------------------------------------------------------------------------*/
/*
/* Reference of 0 not allowed as used as direct key in hash table */
if (counter == 0)
counter++;
+ return counter;
}
-/*---------------------------------------------------------------------------*/
+/*
+ * Returns the reference of the object, or 0 if it is not registered.
+ */
+static guint
+object_to_ref (AtkObject *accessible)
+{
+ return GPOINTER_TO_INT(g_object_get_data (G_OBJECT (accessible), "dbus-id"));
+}
-void
-atk_dbus_foreach_registered(GHFunc func, gpointer data)
+/*
+ * Converts the Accessible object reference to its D-Bus object path
+ */
+static gchar *
+ref_to_path (guint ref)
{
- g_hash_table_foreach(ref2ptr, func, data);
+ return g_strdup_printf(SPI_ATK_OBJECT_REFERENCE_TEMPLATE, ref);
}
/*---------------------------------------------------------------------------*/
/*
- * Called when a registered AtkObject is deleted.
- * Removes the AtkObject from the reference lookup tables.
- * Sets the client side cache to be updated.
+ * 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.
*/
static void
-deregister_accessible(gpointer data, GObject *accessible)
+deregister_accessible (gpointer data, GObject *accessible)
{
guint ref;
- gchar *path;
-
- g_assert(ATK_IS_OBJECT(accessible));
-
-
- ref = atk_dbus_object_to_ref (ATK_OBJECT(accessible));
+ g_assert (ATK_IS_OBJECT (accessible));
+ ref = object_to_ref (ATK_OBJECT(accessible));
if (ref != 0)
{
g_hash_table_remove(ref2ptr, GINT_TO_POINTER(ref));
- /*
- * TODO
- * Pyatspi client side exceptions have occured indicating
- * that an object has been removed twice.
- * This should not be possible and needs investigation.
- */
- spi_emit_cache_removal (ref, atk_adaptor_app_data->bus);
}
}
-/*---------------------------------------------------------------------------*/
-
/*
- * This function registers the object so that it is exported
- * over D-Bus and schedules an update to client side cache.
+ * Called to register an AtkObject with AT-SPI and expose it over D-Bus.
*/
-static guint
-export (GList **uplist, AtkObject *accessible)
+static void
+register_accessible (AtkObject *accessible)
{
guint ref;
- gchar *path;
-
g_assert(ATK_IS_OBJECT(accessible));
ref = assign_reference();
g_hash_table_insert (ref2ptr, GINT_TO_POINTER(ref), accessible);
g_object_set_data (G_OBJECT(accessible), "dbus-id", GINT_TO_POINTER(ref));
g_object_weak_ref(G_OBJECT(accessible), deregister_accessible, NULL);
+}
- *uplist = g_list_prepend (*uplist, accessible);
+/*---------------------------------------------------------------------------*/
+
+#ifdef SPI_ATK_DEBUG
+/*
+ * This function checks that the ref-count of an accessible
+ * is greater than 1.
+ *
+ * There is not currently any remote reference counting
+ * in AT-SPI D-Bus so objects that are remotely owned are not
+ * allowed.
+ *
+ * TODO Add debug wrapper
+ */
+static gboolean
+non_owned_accessible (AtkObject *accessible)
+{
+ if ((G_OBJECT (accessible))->ref_count <= 1)
+ {
+ g_warning ("AT-SPI: Child referenced that is not owned by its parent");
+ return TRUE;
+ }
+ else
+ {
+ return FALSE;
+ }
+}
+#endif /* SPI_ATK_DEBUG */
+
+/*---------------------------------------------------------------------------*/
- return ref;
+static gboolean
+has_manages_descendants (AtkObject *accessible)
+{
+ AtkStateSet *state;
+ gboolean result = FALSE;
+
+ /* This is dangerous, refing the state set
+ * seems to do wierd things to the tree & cause recursion
+ * by modifying the tree alot.
+ */
+ state = atk_object_ref_state_set (accessible);
+ if (atk_state_set_contains_state (state, ATK_STATE_MANAGES_DESCENDANTS))
+ {
+#ifdef SPI_ATK_DEBUG
+ g_warning ("AT-SPI: Object with 'Manages descendants' states not currently handled by AT-SPI");
+#endif
+ result = TRUE;
+ }
+ g_object_unref (state);
+
+ return result;
}
/*
- * This does a depth first traversal of a subtree of AtkObject
- * and exports them as Accessible objects if they are not exported
- * already.
+ * Registers a subtree of accessible objects
+ * rooted at the accessible object provided.
+ *
+ * The leaf nodes do not have their children
+ * registered. A node is considered a leaf
+ * if it has the state "manages-descendants"
+ * or if it has already been registered.
*/
-static guint
-export_subtree (AtkObject *accessible)
+void
+register_subtree (AtkObject *accessible)
{
AtkObject *current, *tmp;
GQueue *stack;
- GList *uplist = NULL;
- guint i, ref;
+ guint i;
gboolean recurse;
- stack = g_queue_new ();
current = g_object_ref (accessible);
- ref = export (&uplist, current);
+ if (has_manages_descendants (current))
+ {
+ g_object_unref (current);
+ return;
+ }
+
+ stack = g_queue_new ();
+
+ register_accessible (current);
g_queue_push_head (stack, GINT_TO_POINTER (0));
/*
*/
while (!g_queue_is_empty (stack))
{
- /* This while loop finds the next node that needs processing,
- * if one exists.
- */
+ /* Find the next child node that needs processing */
+
i = GPOINTER_TO_INT(g_queue_peek_head (stack));
recurse = FALSE;
+
while (i < atk_object_get_n_accessible_children (current) &&
recurse == FALSE)
{
tmp = atk_object_ref_accessible_child (current, i);
- if (!atk_dbus_object_to_ref (tmp))
+
+#ifdef SPI_ATK_DEBUG
+ non_owned_accessible (tmp);
+#endif
+
+ if (object_to_ref (tmp))
{
- recurse = TRUE;
+ /* If its already registered, just update */
+ spi_emit_cache_update (tmp, atk_adaptor_app_data->bus);
+ }
+ else if (has_manages_descendants (tmp))
+ {
+ /* If it has manages descendants, just register and update */
+ register_accessible (tmp);
+ spi_emit_cache_update (tmp, atk_adaptor_app_data->bus);
}
else
{
- i++;
+ recurse = TRUE;
+ }
+
+ if (!recurse)
+ {
g_object_unref (G_OBJECT (tmp));
}
+
+ i++;
}
+
if (recurse)
{
- /* Still children to process */
+ /* Push onto stack */
current = tmp;
- export (&uplist, current);
- /* Update parent nodes next child index */
- g_queue_peek_head_link (stack)->data = GINT_TO_POINTER (i+1);
- /* Push a new child index for the current node */
+ register_accessible (current);
+
+ g_queue_peek_head_link (stack)->data = GINT_TO_POINTER (i);
g_queue_push_head (stack, GINT_TO_POINTER (0));
}
else
{
- /* No more children, move to parent */
+ /* Pop from stack */
+ spi_emit_cache_update (current, atk_adaptor_app_data->bus);
tmp = current;
current = atk_object_get_parent (current);
g_object_unref (G_OBJECT (tmp));
g_queue_pop_head (stack);
}
}
- spi_emit_cache_update (uplist, atk_adaptor_app_data->bus);
- g_list_free (uplist);
- return ref;
+ g_queue_free (stack);
}
/*---------------------------------------------------------------------------*/
-/* Called to register an AtkObject with AT-SPI and expose it over D-Bus. */
-guint
-atk_dbus_register_accessible (AtkObject *accessible)
-{
- guint ref;
- g_assert(ATK_IS_OBJECT(accessible));
-
- ref = atk_dbus_object_to_ref (accessible);
- if (!ref)
- return export_subtree (accessible);
- else
- return ref;
-}
-
-/* Called when an already registered object is updated in such a
+/*
+ * Called when an already registered object is updated in such a
* way that client side cache needs to be updated.
*/
-guint
-atk_dbus_update_accessible (AtkObject *accessible)
+static void
+update_accessible (AtkObject *accessible)
{
- guint ref = 0;
+ guint ref = 0;
g_assert(ATK_IS_OBJECT(accessible));
- ref = atk_dbus_object_to_ref (accessible);
+ ref = object_to_ref (accessible);
if (ref)
{
spi_emit_cache_update (accessible, atk_adaptor_app_data->bus);
}
- return ref;
}
/*---------------------------------------------------------------------------*/
-/*
- * Returns the reference of the object, or 0 if it is not exported over D-Bus.
- */
-guint
-atk_dbus_object_to_ref (AtkObject *accessible)
-{
- return GPOINTER_TO_INT(g_object_get_data (G_OBJECT (accessible), "dbus-id"));
-}
-
-/*
- * Converts the Accessible object reference to its D-Bus object path
- */
-gchar *
-atk_dbus_ref_to_path (guint ref)
+void
+atk_dbus_foreach_registered(GHFunc func, gpointer data)
{
- return g_strdup_printf(ATK_BRIDGE_OBJECT_REFERENCE_TEMPLATE, ref);
+ g_hash_table_foreach(ref2ptr, func, data);
}
/*
g_assert (path);
- if (strncmp(path, ATK_BRIDGE_OBJECT_PATH_PREFIX, ATK_BRIDGE_PATH_PREFIX_LENGTH) != 0)
+ if (strncmp(path, SPI_ATK_OBJECT_PATH_PREFIX, SPI_ATK_PATH_PREFIX_LENGTH) != 0)
return NULL;
- path += ATK_BRIDGE_PATH_PREFIX_LENGTH; /* Skip over the prefix */
+ path += SPI_ATK_PATH_PREFIX_LENGTH; /* Skip over the prefix */
- if (path[0] == '\0')
+ if (!g_strcmp0 (SPI_ATK_OBJECT_PATH_DESKTOP, path))
return atk_get_root();
if (path[0] != '/')
return NULL;
return NULL;
}
-
/*
* Used to lookup a D-Bus path from the AtkObject.
*/
atk_dbus_object_to_path (AtkObject *accessible)
{
guint ref;
- g_assert(ATK_IS_OBJECT(accessible));
- ref = atk_dbus_object_to_ref (accessible);
+ ref = object_to_ref (accessible);
if (!ref)
return NULL;
else
- return atk_dbus_ref_to_path (ref);
+ return ref_to_path (ref);
+}
+
+gchar *
+atk_dbus_desktop_object_path ()
+{
+ return g_strdup (SPI_ATK_OBJECT_PATH_PREFIX SPI_ATK_OBJECT_PATH_DESKTOP);
}
/*---------------------------------------------------------------------------*/
/*
+ * Events are not evaluated for non-registered accessibles.
+ *
+ * When a property change is made on a registered accessible
+ * the client side cache should be updated.
+ *
+ * When a parent is changed the subtree is de-registered
+ * if the parent is not attached to the root accessible.
+ */
+static gboolean
+tree_update_listener (GSignalInvocationHint *signal_hint,
+ guint n_param_values,
+ const GValue *param_values,
+ gpointer data)
+{
+ AtkObject *accessible;
+ AtkPropertyValues *values;
+ const gchar *pname = NULL;
+
+ g_static_rec_mutex_lock (®istration_mutex);
+
+ /* Ensure that only registered accessibles
+ * have their signals processed.
+ */
+ accessible = g_value_get_object (¶m_values[0]);
+ g_assert (ATK_IS_OBJECT (accessible));
+
+ if (object_to_ref (accessible))
+ {
+#ifdef SPI_ATK_DEBUG
+ if (recursion_check_and_set ())
+ g_warning ("AT-SPI: Recursive use of registration module");
+#endif
+
+ values = (AtkPropertyValues*) g_value_get_pointer (¶m_values[1]);
+ pname = values[0].property_name;
+ if (strcmp (pname, "accessible-name") == 0 ||
+ strcmp (pname, "accessible-description") == 0)
+ {
+ update_accessible (accessible);
+ }
+ /* Parent value us updated by child-add signal of parent object */
+
+ recursion_check_unset ();
+ }
+
+ g_static_rec_mutex_unlock (®istration_mutex);
+
+ return TRUE;
+}
+
+/*
+ * Events are not evaluated for non registered accessibles.
+ *
+ * When the children of a registered accessible are changed
+ * the subtree, rooted at the child is registered.
+ */
+static gboolean
+tree_update_children_listener (GSignalInvocationHint *signal_hint,
+ guint n_param_values,
+ const GValue *param_values,
+ gpointer data)
+{
+ AtkObject *accessible;
+ const gchar *detail = NULL;
+ AtkObject *child;
+
+ g_static_rec_mutex_lock (®istration_mutex);
+
+ /* Ensure that only registered accessibles
+ * have their signals processed.
+ */
+ accessible = g_value_get_object (¶m_values[0]);
+ g_assert (ATK_IS_OBJECT (accessible));
+
+ if (object_to_ref (accessible))
+ {
+#ifdef SPI_ATK_DEBUG
+ if (recursion_check_and_set ())
+ g_warning ("AT-SPI: Recursive use of registration module");
+#endif
+
+ if (signal_hint->detail)
+ detail = g_quark_to_string (signal_hint->detail);
+
+ if (!strcmp (detail, "add"))
+ {
+ gpointer child;
+ int index = g_value_get_uint (param_values + 1);
+ child = g_value_get_pointer (param_values + 2);
+
+ if (!ATK_IS_OBJECT (child))
+ {
+ child = atk_object_ref_accessible_child (accessible, index);
+#ifdef SPI_ATK_DEBUG
+ non_owned_accessible (child);
+#endif
+ }
+ register_subtree (child);
+ }
+
+ recursion_check_unset ();
+ }
+
+ g_static_rec_mutex_unlock (®istration_mutex);
+
+ return TRUE;
+}
+
+/*
* Initializes required global data. The update and removal lists
* and the reference lookup tables.
*
if (!ref2ptr)
ref2ptr = g_hash_table_new(g_direct_hash, g_direct_equal);
- /* Get the root accessible and add */
- atk_dbus_register_accessible (root);
+#ifdef SPI_ATK_DEBUG
+ if (g_thread_supported ())
+ g_message ("AT-SPI: Threads enabled");
+#endif
+
+ register_subtree (root);
+
+ atk_add_global_event_listener (tree_update_listener, "Gtk:AtkObject:property-change");
+ atk_add_global_event_listener (tree_update_children_listener, "Gtk:AtkObject:children-changed");
}
/*END------------------------------------------------------------------------*/
projects / platform / core / uifw / at-spi2-atk.git / blobdiff