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

Source/core/frame/PinchViewport.cpp

Index: Source/core/frame/PinchViewport.cpp
diff --git a/Source/core/frame/PinchViewport.cpp b/Source/core/frame/PinchViewport.cpp
index 1410994a5a88d55e2829e63e82a9d96dd5565d27..82c3659d34d7f49e35efb0619649b92917278cb7 100644
--- a/Source/core/frame/PinchViewport.cpp
+++ b/Source/core/frame/PinchViewport.cpp
@@ -64,42 +64,49 @@ namespace WebCore {
 
 PinchViewport::PinchViewport(FrameHost& owner)
     : m_frameHost(owner)
+    , m_scale(1)
 {
 }
 
 PinchViewport::~PinchViewport() { }
 
-void PinchViewport::setSize(const IntSize& newSize)
+void PinchViewport::mainFrameDidChangeSize()
 {
-    // TODO: This is currently called from WebViewImpl with the main frame size which
-    // is (or will be) incorrect, address in future patches.
+    ASSERT(mainFrame() && mainFrame()->view());
 
     if (!m_innerViewportContainerLayer || !m_innerViewportScrollLayer)
         return;
 
+    IntSize newSize = mainFrame()->view()->frameRect().size();
+
     m_innerViewportContainerLayer->setSize(newSize);
     // The innerviewport scroll layer always has the same size as its clip layer, but
     // the page scale layer lives between them, allowing for non-zero max scroll
     // offset when page scale > 1.
     m_innerViewportScrollLayer->setSize(newSize);
 
+    m_offset = clampOffsetToBoundaries(m_offset);
+
     // Need to re-compute sizes for the overlay scrollbars.
     setupScrollbar(WebScrollbar::Horizontal);
     setupScrollbar(WebScrollbar::Vertical);
 }
 
-void PinchViewport::setLocation(const IntPoint& newLocation)
+FloatRect PinchViewport::visibleRect() const
+{
+    FloatSize viewportSize(mainFrame()->view()->frameRect().size());
+    viewportSize.scale(1 / m_scale);
+    return FloatRect(m_offset, viewportSize);
+}
+
+void PinchViewport::setLocation(const FloatPoint& newLocation)
 {
-    // TODO: The update from the LayerTree will occur here before the scale delta is applied.
-    // this means that the clamping below may be incorrect. Once scaling is done in PinchViewport
-    // change it so they happen at the same time.
+    FloatPoint clampedOffset(clampOffsetToBoundaries(newLocation));
 
-    // Clamp the location within our extents.
-    IntPoint location(newLocation);
-    location.shrunkTo(maximumScrollPosition());
-    location.expandedTo(minimumScrollPosition());
+    if (clampedOffset == m_offset)
+        return;
 
-    m_visibleRect.setLocation(newLocation);
+    m_offset = clampedOffset;
 
     ScrollingCoordinator* coordinator = m_frameHost.page().scrollingCoordinator();
     ASSERT(coordinator);
@@ -107,6 +114,19 @@ void PinchViewport::setLocation(const IntPoint& newLocation)
     coordinator->scrollableAreaScrollLayerDidChange(this);
 }
 
+void PinchViewport::setScale(float scale)
+{
+    m_scale = scale;
+
+    // Old-style pinch sets scale here but we shouldn't call into the
+    // clamping code below.
+    if (!m_innerViewportScrollLayer)
+        return;
+
+    // Ensure we clamp so we remain within the bounds.
+    setLocation(visibleRect().location());
+}
+
 // Modifies the top of the graphics layer tree to add layers needed to support
 // the inner/outer viewport fixed-position model for pinch zoom. When finished,
 // the tree will look like this (with * denoting added layers):
@@ -171,6 +191,8 @@ void PinchViewport::attachToLayerTree(GraphicsLayer* currentLayerTreeRoot, Graph
         // Setup the inner viewport overlay scrollbars.
         setupScrollbar(WebScrollbar::Horizontal);
         setupScrollbar(WebScrollbar::Vertical);
+
+        mainFrameDidChangeSize();
     }
 
     m_innerViewportScrollLayer->removeAllChildren();
@@ -260,10 +282,7 @@ IntPoint PinchViewport::minimumScrollPosition() const
 
 IntPoint PinchViewport::maximumScrollPosition() const
 {
-    // TODO: Doesn't take scale into account yet.
-    IntPoint maxScrollPosition(contentsSize() - visibleRect().size());
-    maxScrollPosition.clampNegativeToZero();
-    return maxScrollPosition;
+    return flooredIntPoint(FloatSize(contentsSize()) - visibleRect().size());
 }
 
 IntRect PinchViewport::scrollableAreaBoundingBox() const
@@ -272,7 +291,7 @@ IntRect PinchViewport::scrollableAreaBoundingBox() const
     // space; however, PinchViewport technically isn't a child of any Frames.
     // Nonetheless, the PinchViewport always occupies the entire main frame so just
     // return that.
-    LocalFrame* frame = m_frameHost.page().mainFrame();
+    LocalFrame* frame = mainFrame();
 
     if (!frame || !frame->view())
         return IntRect();
@@ -282,13 +301,13 @@ IntRect PinchViewport::scrollableAreaBoundingBox() const
 
 IntSize PinchViewport::contentsSize() const
 {
-    LocalFrame* frame = m_frameHost.page().mainFrame();
+    LocalFrame* frame = mainFrame();
 
     if (!frame || !frame->view())
         return IntSize();
 
-    // TODO: This will be visibleContentSize once page scale is removed from FrameView
-    return frame->view()->unscaledVisibleContentSize(IncludeScrollbars);
+    ASSERT(frame->view()->visibleContentScaleFactor() == 1);
+    return frame->view()->visibleContentRect(IncludeScrollbars).size();
 }
 
 void PinchViewport::invalidateScrollbarRect(Scrollbar*, const IntRect&)
@@ -330,6 +349,19 @@ void PinchViewport::paintContents(const GraphicsLayer*, GraphicsContext&, Graphi
 {
 }
 
+LocalFrame* PinchViewport::mainFrame() const
+{
+    return m_frameHost.page().mainFrame();
+}
+
+FloatPoint PinchViewport::clampOffsetToBoundaries(const FloatPoint& offset)
+{
+    FloatPoint clampedOffset(offset);
+    clampedOffset = clampedOffset.shrunkTo(FloatPoint(maximumScrollPosition()));
+    clampedOffset = clampedOffset.expandedTo(FloatPoint(minimumScrollPosition()));
+    return clampedOffset;
+}
+
 String PinchViewport::debugName(const GraphicsLayer* graphicsLayer)
 {
     String name;