Fixes: Clever invalidating of the cached clip path.

RevBy:    Andreas
AutoTest: still pass
Details:  Adds emptyClipPath bit, a cut-off to test if the item
	has an empty clip path (i.e., is clipped away). Also adds
	code for invalidating the cache from inside setPos().

1 files changed, 16 insertions, 2 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index 98e7c13..f5c3505 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -139,6 +139,8 @@ public:
         dirtyChildren(0),
         localCollisionHack(0),
         dirtyClipPath(1),
+        emptyClipPath(0),
+        inSetPosHelper(0),
         globalStackingOrder(-1),
         sceneTransformIndex(-1),
         q_ptr(0)
@@ -239,12 +241,22 @@ public:
     {
         cachedClipPath = path;
         dirtyClipPath = 0;
+        emptyClipPath = 0;
     }
 
+    inline void setEmptyCachedClipPath()
+    {
+        emptyClipPath = 1;
+        dirtyClipPath = 0;
+    }
+
+    void setEmptyCachedClipPathRecursively(const QRectF &emptyIfOutsideThisRect = QRectF());
+
     inline void invalidateCachedClipPath()
-    { dirtyClipPath = 1; }
+    { /*static int count = 0 ;qWarning("%i", ++count);*/ dirtyClipPath = 1; emptyClipPath = 0; }
 
-    void invalidateCachedClipPathRecursively(bool childrenOnly = false);
+    void invalidateCachedClipPathRecursively(bool childrenOnly = false, const QRectF &emptyIfOutsideThisRect = QRectF());
+    void updateCachedClipPathFromSetPosHelper();
 
     inline bool isInvisible() const
     {
@@ -288,6 +300,8 @@ public:
     quint32 dirtyChildren : 1;    
     quint32 localCollisionHack : 1;
     quint32 dirtyClipPath : 1;
+    quint32 emptyClipPath : 1;
+    quint32 inSetPosHelper : 1;
 
     // Optional stacking order
     int globalStackingOrder;