Chromium compositor change implementing page-scale driven pinch-zoom.

cc/CCLayerImpl.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CCLayerImpl_h
 #define CCLayerImpl_h
 
 #include "CCInputHandler.h"
 #include "CCLayerAnimationController.h"
 #include "CCRenderSurface.h"
@@ skipping 156 matching lines @@
 
     const IntPoint& scrollPosition() const { return m_scrollPosition; }
     void setScrollPosition(const IntPoint&);
 
     const IntSize& maxScrollPosition() const {return m_maxScrollPosition; }
     void setMaxScrollPosition(const IntSize&);
 
     const FloatSize& scrollDelta() const { return m_scrollDelta; }
     void setScrollDelta(const FloatSize&);
 
+    const FloatSize& localOffset() const { return m_localOffset; }
+    void setLocalOffset(const FloatSize&);
+
     float pageScaleDelta() const { return m_pageScaleDelta; }
     void setPageScaleDelta(float);
 
+    float pageScaleFactor() const { return m_pageScaleFactor; }
+    void setPageScaleFactor(float scale) { m_pageScaleFactor = scale; }
+
     const IntSize& sentScrollDelta() const { return m_sentScrollDelta; }
     void setSentScrollDelta(const IntSize& sentScrollDelta) { m_sentScrollDelta = sentScrollDelta; }
 
-    void scrollBy(const FloatSize& scroll);
+    // Returns the delta of the scroll that was outside of the bounds of the initial scroll
+    FloatSize scrollBy(const FloatSize& scroll);
 
     bool scrollable() const { return m_scrollable; }
     void setScrollable(bool scrollable) { m_scrollable = scrollable; }
 
     bool shouldScrollOnMainThread() const { return m_shouldScrollOnMainThread; }
     void setShouldScrollOnMainThread(bool shouldScrollOnMainThread) { m_shouldScrollOnMainThread = shouldScrollOnMainThread; }
 
     bool haveWheelEventHandlers() const { return m_haveWheelEventHandlers; }
     void setHaveWheelEventHandlers(bool haveWheelEventHandlers) { m_haveWheelEventHandlers = haveWheelEventHandlers; }
 
@@ skipping 132 matching lines @@
 
     // Set for the layer that other layers are fixed to.
     bool m_isContainerForFixedPositionLayers;
     // This is true if the layer should be fixed to the closest ancestor container.
     bool m_fixedToContainerLayer;
 
     FloatSize m_scrollDelta;
     IntSize m_sentScrollDelta;
     IntSize m_maxScrollPosition;
     float m_pageScaleDelta;
+    float m_pageScaleFactor;
+    FloatSize m_localOffset;
 
     // The layer whose coordinate space this layer draws into. This can be
     // either the same layer (m_renderTarget == this) or an ancestor of this
     // layer.
     CCLayerImpl* m_renderTarget;
 
     // The global depth value of the center of the layer. This value is used
     // to sort layers from back to front.
     float m_drawDepth;
     float m_drawOpacity;
@@ skipping 36 matching lines @@
 
     // Manages scrollbars for this layer
     OwnPtr<CCScrollbarAnimationController> m_scrollbarAnimationController;
 };
 
 void sortLayers(Vector<CCLayerImpl*>::iterator first, Vector<CCLayerImpl*>::iterator end, CCLayerSorter*);
 
 }
 
 #endif // CCLayerImpl_h