Don't needlessly setup compositing twice during startup.

Xrandr seems to like to send events about "changes" right
after application startup.


svn path=/trunk/KDE/kdebase/workspace/; revision=923829

composite.cpp

@@ -175,10 +175,8 @@ void Workspace::setupCompositing()
         { // autoconfigure refresh rate based on XRandR info
         if( Extensions::randrAvailable() )
             {
-            XRRScreenConfiguration *config;
-
-            config = XRRGetScreenInfo( display(), rootWindow() );
-            rate = XRRConfigCurrentRate( config );
+            XRRScreenConfiguration *config = XRRGetScreenInfo( display(), rootWindow() );
+            rate = xrrRefreshRate = XRRConfigCurrentRate( config );
             XRRFreeScreenConfigInfo( config );
             }
         }

events.cpp

@@ -501,15 +501,21 @@ bool Workspace::workspaceEvent( XEvent * e )
                 {
 #ifdef HAVE_XRANDR
                 XRRUpdateConfiguration( e );
-#endif
                 if( compositing() )
                     {
                     // desktopResized() should take care of when the size or
                     // shape of the desktop has changed, but we also want to
                     // catch refresh rate changes
-                    finishCompositing();
-                    QTimer::singleShot( 0, this, SLOT( setupCompositing() ) );
+                    XRRScreenConfiguration *config = XRRGetScreenInfo( display(), rootWindow() );
+                    bool changed = ( xrrRefreshRate != XRRConfigCurrentRate( config ));
+                    XRRFreeScreenConfigInfo( config );
+                    if( changed )
+                        {
+                        finishCompositing();
+                        QTimer::singleShot( 0, this, SLOT( setupCompositing() ) );
+                        }
                     }
+#endif
                 }
             else if( e->type == Extensions::syncAlarmNotifyEvent() && Extensions::syncAvailable())
                 {

workspace.cpp

@@ -139,6 +139,7 @@ Workspace::Workspace( bool restore )
     , cm_selection( NULL )
     , compositingSuspended( false )
     , compositeRate( 0 )
+    , xrrRefreshRate( 0 )
     , overlay( None )
     , overlay_visible( true )
     , overlay_shown( false )

workspace.h

@@ -774,6 +774,7 @@ class Workspace : public QObject, public KDecorationDefines
         QTime nextPaintReference;
         QTimer mousePollingTimer;
         int compositeRate;
+        int xrrRefreshRate; // used only for compositing
         QRegion repaints_region;
         Window overlay; // XComposite overlay window
         bool overlay_visible;