Quick: Do not calculate the difference in a geometryChange

This difference is only used by the ListView, so calculating it and
storing it (on the stack) introduces a penalty for all items. As the new
geometry is already applied, the old geometry is passed along. This has
the added advantage that the ListView does not have to re-calculate that
either. This fixes a performance regression.

Change-Id: Id5e67bb663a5b11a55ec15ff24ca5b213d1fcef5
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/quick/items/qquickitemchangelistener_p.h b/src/quick/items/qquickitemchangelistener_p.h
index 19ff73056b..83c69a9330 100644
--- a/src/quick/items/qquickitemchangelistener_p.h
+++ b/src/quick/items/qquickitemchangelistener_p.h
@@ -115,12 +115,14 @@ private:
     int kind;
 };
 
+#define QT_QUICK_NEW_GEOMETRY_CHANGED_HANDLING
+
 class QQuickItemChangeListener
 {
 public:
     virtual ~QQuickItemChangeListener() {}
 
-    virtual void itemGeometryChanged(QQuickItem *, QQuickGeometryChange, const QRectF & /* diff */) {}
+    virtual void itemGeometryChanged(QQuickItem *, QQuickGeometryChange, const QRectF & /* oldGeometry */) {}
     virtual void itemSiblingOrderChanged(QQuickItem *) {}
     virtual void itemVisibilityChanged(QQuickItem *) {}
     virtual void itemOpacityChanged(QQuickItem *) {}