diff -r f93c875b566e -r 3a60ebea00d0 uiacceltk/hitchcock/coretoolkit/src/HuiCanvasVisual.cpp
--- a/uiacceltk/hitchcock/coretoolkit/src/HuiCanvasVisual.cpp	Tue May 25 13:39:57 2010 +0300
+++ b/uiacceltk/hitchcock/coretoolkit/src/HuiCanvasVisual.cpp	Wed Jun 09 10:41:25 2010 +0300
@@ -244,13 +244,13 @@
     HandleBuffer(scannedRect, EScanBuffer, NULL); 
     
     // Note: this could be improved to take care of dirty rects 
-    if (Effect() && Display())
+    if (Effect() && Display() && CHuiEnv::Static()->MemoryLevel() != EHuiMemoryLevelLowest )
         {        
         // If there is effect enabled, we cannot say anything about dirty area so
         // we set whole screen dirty.
         scannedRect = TRect(TPoint(0,0), Display()->VisibleArea().Size());
         }
-    else if (IsBackgroundDrawingEnabled() || IsExternalContentDrawingEnabled())
+    else if (IsExternalContentDrawingEnabled())
         {
         // If the visual has external content or draws background, 
         // set always the whole window area as a content.
@@ -349,6 +349,8 @@
     
     if (Effect())
         {
+        TBool hasStoredContent = (IsDelayedEffectSource() || Freezed()) && (StoredRenderBuffer() ||  iCanvasVisualData->iStoredRenderBuffer);
+    
         TBool semiTranparentEffectActive = Effect()->IsSemitransparent();
         if ((iOpacity.Now() <= EPSILON && !semiTranparentEffectActive))
             {
@@ -361,7 +363,8 @@
             !HasCommandBuffers(ETrue /*include children*/) && 
             !IsBackgroundDrawingEnabled() &&
             !IsExternalContentDrawingEnabled()&&
-            !IsExternalContentDrawingEnabled(ETrue /*include children*/))
+            !IsExternalContentDrawingEnabled(ETrue /*include children*/) &&
+            !hasStoredContent )
             {
             return ETrue;
             }
@@ -456,26 +459,27 @@
         transparent |= iOpacity.Now() < 1.0f; // Opacity less than 1.0f -> always transparent
                 
         TBool refreshCache = EFalse;        
+        TBool layer =  EFalse;
         if (EffectIsAppliedToChildren())
             {
             refreshCache |= ChildTreeChanged(EHuiCanvasFlagExcludeFromParentEffect);
 
             iCanvasVisualData->iPaintedRegion.Clear();
-            CollectRecursivePaintedRegion(iCanvasVisualData->iPaintedRegion, EHuiCanvasFlagExcludeFromParentEffect);
+            layer = CollectRecursivePaintedRegion(iCanvasVisualData->iPaintedRegion, EHuiCanvasFlagExcludeFromParentEffect);
             }
         else
             {
             refreshCache |= Changed();            
 
             iCanvasVisualData->iPaintedRegion.Clear();
-            CollectPaintedRegion(iCanvasVisualData->iPaintedRegion, 0);
+            layer = CollectPaintedRegion(iCanvasVisualData->iPaintedRegion, 0);
             }
 
         if(Display()->RosterImpl().AlfEventWindow() == this)
             {
             refreshCache |= Display()->RosterImpl().NativeAppsContentChanged();
             }
-        didDrawEffect = Effect()->CachedDraw(aGc, area, refreshCache, !transparent, iCanvasVisualData->iPaintedRegion);
+        didDrawEffect = Effect()->CachedDraw(aGc, area, refreshCache, !transparent, iCanvasVisualData->iPaintedRegion,layer );
         
         }
     
@@ -547,8 +551,8 @@
 #endif		
     TBool alfEventWindow = (Display()->RosterImpl().AlfEventWindow() == this);
     TReal32 effectiveOpacity = EffectiveOpacity();
-        
-    if ((effectiveOpacity <= 0 || !HasCommandBuffers(ETrue)) && !alfEventWindow)
+    TBool hasStoredContent = (IsContentDrawingEnabled() && (IsDelayedEffectSource() || Freezed())) && (StoredRenderBuffer() || iCanvasVisualData->iStoredRenderBuffer);        
+    if ((effectiveOpacity <= 0 || !HasCommandBuffers(ETrue)) && !alfEventWindow && !hasStoredContent)
         {
         // In case background drawing is enabled, and even if we don't have command buffers we still
         // want to issue clear. If the background drawing is enabled here, it means that the
@@ -564,7 +568,7 @@
             }
         }
 
-    if (IsContentDrawingEnabled() && (IsDelayedEffectSource() || Freezed()))
+    if (hasStoredContent)
         {
         // Select right draw mode
         THuiCanvasDrawMode drawMode = (Flags() & EHuiVisualFlagOpaqueHint) ? EHuiCanvasDrawModeNormal : EHuiCanvasDrawModeBlend;
@@ -889,7 +893,12 @@
         PrepareCache();
         }
     
-    SetChanged();
+    // don't call setchanged directly here, as it changes all
+    // the command buffers dirty. We don't want to do that
+    // as the drawing area might be significantly smaller in
+    // some cases
+    CHuiLayout::SetChanged();
+    Env().ContinueRefresh(ETrue);
     Env().CanvasTextureCache().EnableTouchCountCheck(EFalse);    
     }
 
@@ -1525,7 +1534,7 @@
 		}
     }
 
-void CHuiCanvasVisual::CollectPaintedRegion(TRegion& aPaintRegion, TInt aExcludeCanvasFlags) const
+TBool CHuiCanvasVisual::CollectPaintedRegion(TRegion& aPaintRegion, TInt aExcludeCanvasFlags) const
     {
     // Only our own painted areas.
     TInt paintedAreaCount = PaintedAreaCount();  
@@ -1534,12 +1543,13 @@
         aPaintRegion.AddRect( CanvasPaintedArea(i).iPaintedRect.Round() );
         }
     aPaintRegion.Tidy();
+    return !iCanvasVisualData->iLayerExtent.IsEmpty();
     }
 
-void CHuiCanvasVisual::CollectRecursivePaintedRegion(TRegion& aRecursivePaintRegion, TInt aExcludeCanvasFlags) const
+TBool CHuiCanvasVisual::CollectRecursivePaintedRegion(TRegion& aRecursivePaintRegion, TInt aExcludeCanvasFlags) const
     {
     // First our own painted areas...
-    CollectPaintedRegion(aRecursivePaintRegion, aExcludeCanvasFlags);
+    TBool layer = CollectPaintedRegion(aRecursivePaintRegion, aExcludeCanvasFlags);
             
     // ...then children (and their children).
     const TInt count = Count();
@@ -1559,13 +1569,14 @@
                     if (visual->Flags() & EHuiVisualFlagWserv)
                         {
                         CHuiCanvasVisual* canvasVisual = (CHuiCanvasVisual*)visual;
-                        canvasVisual->CollectRecursivePaintedRegion(aRecursivePaintRegion, aExcludeCanvasFlags);
+                        layer |= canvasVisual->CollectRecursivePaintedRegion(aRecursivePaintRegion, aExcludeCanvasFlags);
                         }
                     }
                 }        
             }
         }    
     aRecursivePaintRegion.Tidy();
+    return layer;
     }
 
 EXPORT_C TRect CHuiCanvasVisual::CommandBufferCoverage(TInt aOrientation)