Better painting of moved window.

svn path=/branches/work/kwin_composite/; revision=656410

COMPOSITE_TODO

@@ -179,6 +179,12 @@ Effects framework TODO
 
 * check Scene::updateTimeDiff() - should the time be 0 or 1?
 
+* DesktopGridEffect has somewhat broken stacking order while moving windows
+    - the window is in proper layer when on its desktop but on top of everything when moved
+        to another desktop, due to its desktop being painted later
+    - maybe there should be PAINT_WINDOW_TOP (_LAST or whatever) that'd make it painted always
+        on top of everything
+
 
 Effects TODO
 ===============================

effects/desktopgrid.cpp

@@ -98,7 +98,11 @@ void DesktopGridEffect::prePaintWindow( EffectWindow* w, int* mask, QRegion* pai
         else
             w->disablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
         if( w == window_move )
+            {
             *mask |= PAINT_WINDOW_TRANSFORMED;
+            if( w->isOnAllDesktops() && painting_desktop != effects->currentDesktop())
+                w->disablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
+            }
         }
     effects->prePaintWindow( w, mask, paint, clip, time );
     }
@@ -115,10 +119,23 @@ void DesktopGridEffect::paintScreen( int mask, QRegion region, ScreenPaintData&
         paintSlide( mask, region, data );
         return;
         }
+    int desktop_with_move = -1;
+    if( window_move != NULL )
+        desktop_with_move = window_move->isOnAllDesktops() ? effects->currentDesktop() : window_move->desktop();
     for( int desktop = 1;
          desktop <= effects->numberOfDesktops();
          ++desktop )
         {
+        if( desktop != desktop_with_move )
+            paintScreenDesktop( desktop, mask, region, data );
+        }
+    // paint the desktop with the window being moved as the last one, i.e. on top of others
+    if( desktop_with_move != -1 )
+        paintScreenDesktop( desktop_with_move, mask, region, data );
+    }
+
+void DesktopGridEffect::paintScreenDesktop( int desktop, int mask, QRegion region, ScreenPaintData data )
+    {
     QRect rect = desktopRect( desktop, true );
     if( region.contains( rect )) // this desktop needs painting
         {
@@ -133,7 +150,6 @@ void DesktopGridEffect::paintScreen( int mask, QRegion region, ScreenPaintData&
         effects->paintScreen( mask, region, d );
         }
     }
-    }
 
 void DesktopGridEffect::paintSlide( int mask, QRegion region, const ScreenPaintData& data )
     {

effects/desktopgrid.h

@@ -42,6 +42,7 @@ class DesktopGridEffect
         void setup();
         void finish();
         void paintSlide( int mask, QRegion region, const ScreenPaintData& data );
+        void paintScreenDesktop( int desktop, int mask, QRegion region, ScreenPaintData data );
         void slideDesktopChanged( int old );
         float progress;
         bool activated;