[Pinch-to-zoom] Moved scale factor into PinchViewport

Source/core/frame/PinchViewport.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef PinchViewport_h
 #define PinchViewport_h
 
+#include "platform/geometry/FloatPoint.h"
+#include "platform/geometry/FloatRect.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/graphics/GraphicsLayerClient.h"
 #include "platform/scroll/ScrollableArea.h"
 #include "public/platform/WebScrollbar.h"
 #include "public/platform/WebSize.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
 
 namespace blink {
 class WebLayerTreeView;
 class WebScrollbarLayer;
 }
 
 namespace WebCore {
 
 class FrameHost;
 class GraphicsContext;
 class GraphicsLayer;
 class GraphicsLayerFactory;
 class IntRect;
 class IntSize;
+class LocalFrame;
 
+// Represents the pinch-to-zoom viewport the user is currently seeing the page through. This
+// class corresponds to the InnerViewport on the compositor. It is a ScrollableArea; it's
+// offset is set through the GraphicsLayer <-> CC sync mechanisms. Its contents is the page's
+// main FrameView, which corresponds to the outer viewport. The inner viewport is always contained
+// in the outer viewport and can pan within it.
 class PinchViewport FINAL : public GraphicsLayerClient, public ScrollableArea {
 public:
     PinchViewport(FrameHost&);
     virtual ~PinchViewport();
 
     void attachToLayerTree(GraphicsLayer*, GraphicsLayerFactory*);
     GraphicsLayer* rootGraphicsLayer()
     {
         return m_innerViewportContainerLayer.get();
     }
 
     void setLocation(const IntPoint&);
-    void setSize(const IntSize&);
+    void mainFrameDidChangeSize();
+
+    void setScale(float scale) { m_scale = scale; }
+    float scale() const { return m_scale; }
 
     void registerLayersWithTreeView(blink::WebLayerTreeView*) const;
     void clearLayersForTreeView(blink::WebLayerTreeView*) const;
 
-    IntRect visibleRect() const { return m_visibleRect; }
+    // The portion of the unzoomed frame visible in the inner "pinch" viewport, in partial CSS pixels.
+    FloatRect visibleRect() const;
 private:
     // ScrollableArea implementation
     virtual bool isActive() const OVERRIDE { return false; }
     virtual int scrollSize(ScrollbarOrientation) const OVERRIDE;
     virtual bool isScrollCornerVisible() const OVERRIDE { return false; }
     virtual IntRect scrollCornerRect() const OVERRIDE { return IntRect(); }
-    virtual IntPoint scrollPosition() const OVERRIDE { return visibleRect().location(); }
+    virtual IntPoint scrollPosition() const OVERRIDE { return flooredIntPoint(m_offset); }
     virtual IntPoint minimumScrollPosition() const OVERRIDE;
     virtual IntPoint maximumScrollPosition() const OVERRIDE;
     virtual int visibleHeight() const OVERRIDE { return visibleRect().height(); };
     virtual int visibleWidth() const OVERRIDE { return visibleRect().width(); };
     virtual IntSize contentsSize() const OVERRIDE;
     virtual bool scrollbarsCanBeActive() const OVERRIDE { return false; }
     virtual IntRect scrollableAreaBoundingBox() const OVERRIDE;
     virtual bool userInputScrollable(ScrollbarOrientation) const OVERRIDE { return true; }
     virtual bool shouldPlaceVerticalScrollbarOnLeft() const OVERRIDE { return false; }
     virtual void invalidateScrollbarRect(Scrollbar*, const IntRect&) OVERRIDE;
     virtual void invalidateScrollCornerRect(const IntRect&) OVERRIDE { }
     virtual void setScrollOffset(const IntPoint&) OVERRIDE;
     virtual GraphicsLayer* layerForContainer() const OVERRIDE;
     virtual GraphicsLayer* layerForScrolling() const OVERRIDE;
     virtual GraphicsLayer* layerForHorizontalScrollbar() const OVERRIDE;
     virtual GraphicsLayer* layerForVerticalScrollbar() const OVERRIDE;
 
     // GraphicsLayerClient implementation.
     virtual void notifyAnimationStarted(const GraphicsLayer*, double monotonicTime) OVERRIDE;
     virtual void paintContents(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase, const IntRect& inClip) OVERRIDE;
     virtual String debugName(const GraphicsLayer*) OVERRIDE;
 
     void setupScrollbar(blink::WebScrollbar::Orientation);
+    FloatPoint clampOffsetToBoundaries(const FloatPoint&);
+
+    LocalFrame* mainFrame() const;
 
     FrameHost& m_frameHost;
     OwnPtr<GraphicsLayer> m_innerViewportContainerLayer;
     OwnPtr<GraphicsLayer> m_pageScaleLayer;
     OwnPtr<GraphicsLayer> m_innerViewportScrollLayer;
     OwnPtr<GraphicsLayer> m_overlayScrollbarHorizontal;
     OwnPtr<GraphicsLayer> m_overlayScrollbarVertical;
     OwnPtr<blink::WebScrollbarLayer> m_webOverlayScrollbarHorizontal;
     OwnPtr<blink::WebScrollbarLayer> m_webOverlayScrollbarVertical;
 
-    IntRect m_visibleRect;
+    // Offset of the pinch viewport from the main frame's origin, in CSS pixels.
+    FloatPoint m_offset;
+    float m_scale;
 };
 
 } // namespace WebCore
 
 #endif // PinchViewport_h