[gnome-desktop] GnomeRR: use a DBus signal instead of XRandR events to refresh

[Giovanni Campagna <gcampagna src gnome org>]

commit ab2e60a60da70ab70941615835806d1c0fcca3b5
Author: Giovanni Campagna <gcampagn redhat com>
Date:   Tue Aug 20 13:28:30 2013 +0200

    GnomeRR: use a DBus signal instead of XRandR events to refresh
    
    Using a DBus signal we avoid the race, and make sure that we
    get the updated values in the next call to mutter.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=706383

 libgnome-desktop/gnome-rr.c |    6 +++---
 libgnome-desktop/xrandr.xml |   11 +++++++++--
 2 files changed, 12 insertions(+), 5 deletions(-)
---
diff --git a/libgnome-desktop/gnome-rr.c b/libgnome-desktop/gnome-rr.c
index 2d1613a..5b56ff4 100644
--- a/libgnome-desktop/gnome-rr.c
+++ b/libgnome-desktop/gnome-rr.c
@@ -540,7 +540,7 @@ screen_update (GnomeRRScreen *screen, gboolean force_callback, GError **error)
 }
 
 static void
-screen_on_monitors_changed (GdkScreen *gdk_screen,
+screen_on_monitors_changed (MetaDBusDisplayConfig *proxy,
                            gpointer data)
 {
     GnomeRRScreen *screen = data;
@@ -569,7 +569,7 @@ gnome_rr_screen_initable_init (GInitable *initable, GCancellable *canc, GError *
     if (!priv->info)
        return FALSE;
 
-    g_signal_connect_object (priv->gdk_screen, "monitors-changed",
+    g_signal_connect_object (priv->proxy, "monitors-changed",
                             G_CALLBACK (screen_on_monitors_changed), self, 0);
     return TRUE;
 }
@@ -596,7 +596,7 @@ on_proxy_acquired (GObject      *object,
     if (!priv->info)
        return g_task_return_error (task, error);
 
-    g_signal_connect_object (priv->gdk_screen, "monitors-changed",
+    g_signal_connect_object (priv->proxy, "monitors-changed",
                             G_CALLBACK (screen_on_monitors_changed), self, 0);
     g_task_return_boolean (task, TRUE);
 }
diff --git a/libgnome-desktop/xrandr.xml b/libgnome-desktop/xrandr.xml
index b0db9a0..d8574ad 100644
--- a/libgnome-desktop/xrandr.xml
+++ b/libgnome-desktop/xrandr.xml
@@ -149,11 +149,9 @@
 
        @serial must match the serial from the last GetResources() call,
        or org.freedesktop.DBus.AccessDenied will be generated.
-       (XXX: a better error maybe?)
 
        If @persistent is true, mutter will attempt to replicate this
        configuration the next time this HW layout appears.
-       (XXX: or is this gnome-settings-daemon role?)
 
        @crtcs represents the new logical configuration, as a list
        of structures containing:
@@ -279,5 +277,14 @@
        XRandR interface directly).
     -->
     <property name="PowerSaveMode" type="i" access="readwrite" />
+
+    <!--
+        MonitorsChanged:
+
+       The signal is emitted every time the screen configuration
+       changes.
+       The client should then call GetResources() to read the new layout.
+    -->
+    <signal name="MonitorsChanged" />
   </interface>
 </node>