gtk2/gtk/a11y/gtkaccessibilityutil.c
Carlos Garnacho 054165d406 a11y: Avoid clobbering AtkUtilClass vmethods
In the unlikely case that GTK is "embedded" with other toolkits
(hi, Mutter), GTK will clobber the embedder's AtkUtil implementation,
leaving its own a11y in a broken state.

AtkUtil is not meant to be overridden by multiple toolkits within a
single client, so the most sensible thing to do is stay away from it
if that is the case. This helps the embedder's a11y to win.

Fixes Clutter a11y in Mutter after xwayland-on-demand, process
startup used to be in a fixed order so that Clutter's a11y would
eventually win, but x11/gtk startup is now asynchronous and able to
happen at a later point.

Closes: https://gitlab.gnome.org/GNOME/gnome-shell/issues/1687
2019-09-27 18:15:44 +02:00

159 lines
3.8 KiB
C

/* GTK+ - accessibility implementations
* Copyright 2011, F123 Consulting & Mais Diferenças
* Copyright 2001, 2002, 2003 Sun Microsystems Inc.
*
* 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 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
* 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/>.
*/
#include "config.h"
#include <stdlib.h>
#include <gtk/gtk.h>
#include "gtkaccessibility.h"
#include "gtkaccessibilityutil.h"
#include "gtktoplevelaccessible.h"
static GSList *key_listener_list = NULL;
typedef struct {
AtkKeySnoopFunc func;
gpointer data;
guint key;
} KeyEventListener;
static guint
add_key_event_listener (AtkKeySnoopFunc listener_func,
gpointer listener_data)
{
static guint key = 0;
KeyEventListener *listener;
key++;
listener = g_slice_new0 (KeyEventListener);
listener->func = listener_func;
listener->data = listener_data;
listener->key = key;
key_listener_list = g_slist_append (key_listener_list, listener);
return key;
}
static void
remove_key_event_listener (guint listener_key)
{
GSList *l;
for (l = key_listener_list; l; l = l->next)
{
KeyEventListener *listener = l->data;
if (listener->key == listener_key)
{
g_slice_free (KeyEventListener, listener);
key_listener_list = g_slist_delete_link (key_listener_list, l);
break;
}
}
}
static AtkObject *
get_root (void)
{
static AtkObject *root = NULL;
if (!root)
{
root = g_object_new (GTK_TYPE_TOPLEVEL_ACCESSIBLE, NULL);
atk_object_initialize (root, NULL);
}
return root;
}
static const gchar *
get_toolkit_name (void)
{
return "gtk";
}
static const gchar *
get_toolkit_version (void)
{
return GTK_VERSION;
}
void
_gtk_accessibility_override_atk_util (void)
{
AtkUtilClass *atk_class = ATK_UTIL_CLASS (g_type_class_ref (ATK_TYPE_UTIL));
if (atk_class->get_root)
return;
atk_class->add_key_event_listener = add_key_event_listener;
atk_class->remove_key_event_listener = remove_key_event_listener;
atk_class->get_root = get_root;
atk_class->get_toolkit_name = get_toolkit_name;
atk_class->get_toolkit_version = get_toolkit_version;
}
static void
atk_key_event_from_gdk_event_key (GdkEventKey *key,
AtkKeyEventStruct *event)
{
if (key->type == GDK_KEY_PRESS)
event->type = ATK_KEY_EVENT_PRESS;
else if (key->type == GDK_KEY_RELEASE)
event->type = ATK_KEY_EVENT_RELEASE;
else
g_assert_not_reached ();
event->state = key->state;
event->keyval = key->keyval;
event->length = key->length;
if (key->string && key->string[0] &&
g_unichar_isgraph (g_utf8_get_char (key->string)))
event->string = key->string;
else
event->string = gdk_keyval_name (key->keyval);
event->keycode = key->hardware_keycode;
event->timestamp = key->time;
}
gboolean
_gtk_accessibility_key_snooper (GtkWidget *widget,
GdkEventKey *event)
{
GSList *l;
AtkKeyEventStruct atk_event;
gboolean result;
result = FALSE;
atk_key_event_from_gdk_event_key (event, &atk_event);
for (l = key_listener_list; l; l = l->next)
{
KeyEventListener *listener = l->data;
result |= listener->func (&atk_event, listener->data);
}
return result;
}