[mutter] backends: Add a keymap-layout-group-changed signal

[Rui Matos <rtcm src gnome org>]

commit 59c5ac0cb57769ed635372e17deddafcbe3a4589
Author: Rui Matos <tiagomatos gmail com>
Date:   Wed Sep 10 19:16:01 2014 +0200

    backends: Add a keymap-layout-group-changed signal
    
    We'll need this in the wayland frontend to send a modifiers event to
    clients.
    
    Note that on X11 this isn't needed because key events include the
    group index encoded in modifier state. If we ever want to make the
    wayland frontend work with the X11 backend we'll handle it then.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=736433

 src/backends/meta-backend.c               |    6 ++++++
 src/backends/native/meta-backend-native.c |    1 +
 2 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/src/backends/meta-backend.c b/src/backends/meta-backend.c
index 4242081..a3b74ed 100644
--- a/src/backends/meta-backend.c
+++ b/src/backends/meta-backend.c
@@ -254,6 +254,12 @@ meta_backend_class_init (MetaBackendClass *klass)
                 0,
                 NULL, NULL, NULL,
                 G_TYPE_NONE, 0);
+  g_signal_new ("keymap-layout-group-changed",
+                G_TYPE_FROM_CLASS (object_class),
+                G_SIGNAL_RUN_LAST,
+                0,
+                NULL, NULL, NULL,
+                G_TYPE_NONE, 1, G_TYPE_UINT);
 }
 
 static void
diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index cb9d3a7..6e2741b 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/src/backends/native/meta-backend-native.c
@@ -229,6 +229,7 @@ meta_backend_native_lock_layout_group (MetaBackend *backend,
 {
   ClutterDeviceManager *manager = clutter_device_manager_get_default ();
   clutter_evdev_set_keyboard_layout_index (manager, idx);
+  g_signal_emit_by_name (backend, "keymap-layout-group-changed", idx, 0);
 }
 
 static void