Relayout on monitor layout changes

Currently we only relayout when the screen size changes, this gets
 the cases where a monitor gets added/removed but not when the primary
 monitor changes.

 We need to relayout on all monitor layout changes.

 Remove ShellGlobal::screen-size-changed signal as it is no longer used, Gdk is
 used to track changes now.

 A ShellGlobal::gdk-screen property is added for this purpose.

https://bugzilla.gnome.org/show_bug.cgi?id=620377

js/ui/main.js

@@ -159,7 +159,7 @@ function start() {
     global.stage.add_actor(background);
     background.lower_bottom();
 
-    global.connect('screen-size-changed', _relayout);
+    global.gdk_screen.connect('monitors-changed', _relayout);
 
     ExtensionSystem.init();
     ExtensionSystem.loadExtensions();

js/ui/messageTray.js

@@ -452,8 +452,8 @@ MessageTray.prototype = {
         Main.chrome.trackActor(this._notificationBin);
         Main.chrome.trackActor(this._summaryNotificationBin);
 
-        global.connect('screen-size-changed',
+        global.gdk_screen.connect('monitors-changed', Lang.bind(this, this._setSizePosition));
-                       Lang.bind(this, this._setSizePosition));
+
         this._setSizePosition();
 
         Main.overview.connect('showing', Lang.bind(this,

src/shell-global.c

@@ -69,6 +69,7 @@ enum {
 
   PROP_OVERLAY_GROUP,
   PROP_SCREEN,
+  PROP_GDK_SCREEN,
   PROP_SCREEN_WIDTH,
   PROP_SCREEN_HEIGHT,
   PROP_STAGE,
@@ -79,17 +80,8 @@ enum {
   PROP_USERDATADIR,
 };
 
-/* Signals */
-enum
-{
-  SCREEN_SIZE_CHANGED,
-  LAST_SIGNAL
-};
-
 G_DEFINE_TYPE(ShellGlobal, shell_global, G_TYPE_OBJECT);
 
-static guint shell_global_signals [LAST_SIGNAL] = { 0 };
-
 static void
 shell_global_set_property(GObject         *object,
                           guint            prop_id,
@@ -120,6 +112,9 @@ shell_global_get_property(GObject         *object,
     case PROP_SCREEN:
       g_value_set_object (value, shell_global_get_screen (global));
       break;
+    case PROP_GDK_SCREEN:
+      g_value_set_object (value, shell_global_get_gdk_screen (global));
+      break;
     case PROP_SCREEN_WIDTH:
       {
         int width, height;
@@ -207,15 +202,6 @@ shell_global_class_init (ShellGlobalClass *klass)
   gobject_class->get_property = shell_global_get_property;
   gobject_class->set_property = shell_global_set_property;
 
-  shell_global_signals[SCREEN_SIZE_CHANGED] =
-    g_signal_new ("screen-size-changed",
-		  G_TYPE_FROM_CLASS (klass),
-		  G_SIGNAL_RUN_LAST,
-		  G_STRUCT_OFFSET (ShellGlobalClass, screen_size_changed),
-		  NULL, NULL,
-		  g_cclosure_marshal_VOID__VOID,
-		  G_TYPE_NONE, 0);
-
   g_object_class_install_property (gobject_class,
                                    PROP_OVERLAY_GROUP,
                                    g_param_spec_object ("overlay-group",
@@ -230,6 +216,15 @@ shell_global_class_init (ShellGlobalClass *klass)
                                                         "Metacity screen object for the shell",
                                                         META_TYPE_SCREEN,
                                                         G_PARAM_READABLE));
+
+  g_object_class_install_property (gobject_class,
+                                   PROP_GDK_SCREEN,
+                                   g_param_spec_object ("gdk-screen",
+                                                        "GdkScreen",
+                                                        "Gdk screen object for the shell",
+                                                        GDK_TYPE_SCREEN,
+                                                        G_PARAM_READABLE));
+
   g_object_class_install_property (gobject_class,
                                    PROP_SCREEN_WIDTH,
                                    g_param_spec_int ("screen-width",
@@ -425,6 +420,19 @@ shell_global_get_screen (ShellGlobal  *global)
   return mutter_plugin_get_screen (global->plugin);
 }
 
+/**
+ * shell_global_get_gdk_screen:
+ *
+ * Return value: (transfer none): Gdk screen object for the shell
+ */
+GdkScreen *
+shell_global_get_gdk_screen (ShellGlobal *global)
+{
+  g_return_val_if_fail (SHELL_IS_GLOBAL (global), NULL);
+
+  return gdk_screen_get_default ();
+}
+
 /**
  * shell_global_get_windows:
  *
@@ -441,9 +449,10 @@ shell_global_get_windows (ShellGlobal *global)
 }
 
 static gboolean
-update_screen_size (ShellGlobal *global)
+update_screen_size (gpointer data)
 {
   int width, height;
+  ShellGlobal *global = SHELL_GLOBAL (data);
 
   mutter_plugin_query_screen_size (global->plugin, &width, &height);
 
@@ -458,17 +467,6 @@ update_screen_size (ShellGlobal *global)
     clutter_actor_set_size (CLUTTER_ACTOR (global->root_pixmap),
                             width, height);
 
-  return TRUE;
-}
-
-static gboolean
-on_screen_size_changed_cb (gpointer data)
-{
-  ShellGlobal *global = SHELL_GLOBAL (data);
-
-  if (update_screen_size (global))
-    g_signal_emit (G_OBJECT (global), shell_global_signals[SCREEN_SIZE_CHANGED], 0);
-
   return FALSE;
 }
 
@@ -482,7 +480,7 @@ global_stage_notify_width (GObject    *gobject,
   g_object_notify (G_OBJECT (global), "screen-width");
 
   meta_later_add (META_LATER_BEFORE_REDRAW,
-                  on_screen_size_changed_cb,
+                  update_screen_size,
                   global,
                   NULL);
 }
@@ -497,7 +495,7 @@ global_stage_notify_height (GObject    *gobject,
   g_object_notify (G_OBJECT (global), "screen-height");
 
   meta_later_add (META_LATER_BEFORE_REDRAW,
-                  on_screen_size_changed_cb,
+                  update_screen_size,
                   global,
                   NULL);
 }
@@ -1167,7 +1165,7 @@ shell_global_get_monitors (ShellGlobal *global)
 GdkRectangle *
 shell_global_get_primary_monitor (ShellGlobal  *global)
 {
-  GdkScreen *screen = gdk_screen_get_default ();
+  GdkScreen *screen = shell_global_get_gdk_screen (global);
   GdkRectangle rect;
   gint primary = 0;
 

src/shell-global.h

@@ -25,8 +25,6 @@ typedef struct _ShellGlobalClass ShellGlobalClass;
 struct _ShellGlobalClass
 {
   GObjectClass parent_class;
-
-  void (*screen_size_changed) (ShellGlobal *global);
 };
 
 GType            shell_global_get_type            (void) G_GNUC_CONST;
@@ -40,6 +38,8 @@ ShellGlobal *shell_global_get (void);
 
 MetaScreen *shell_global_get_screen (ShellGlobal  *global);
 
+GdkScreen *shell_global_get_gdk_screen (ShellGlobal  *global);
+
 gboolean shell_global_add_extension_importer (ShellGlobal *global,
                                               const char  *target_object_script,
                                               const char  *target_property,