Pinch/Zoom Infrastructure & Plumbing CL (Prequel)

Source/core/page/scrolling/ScrollingCoordinator.cpp

 /*
  * Copyright (C) 2011 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 62 matching lines @@
 {
     return layer->platformLayer();
 }
 
 WebLayer* ScrollingCoordinator::scrollingWebLayerForScrollableArea(ScrollableArea* scrollableArea)
 {
     GraphicsLayer* graphicsLayer = scrollLayerForScrollableArea(scrollableArea);
     return graphicsLayer ? scrollingWebLayerForGraphicsLayer(graphicsLayer) : 0;
 }
 
+WebLayer* ScrollingCoordinator::containerWebLayerForScrollableArea(ScrollableArea* scrollableArea)
+{
+    GraphicsLayer* graphicsLayer = scrollLayerForScrollableArea(scrollableArea);
+    if (!graphicsLayer)
+        return 0;
+    graphicsLayer = graphicsLayer->parent();
+    return graphicsLayer ? graphicsLayer->platformLayer() : 0;
+}
+
 PassRefPtr<ScrollingCoordinator> ScrollingCoordinator::create(Page* page)
 {
     return adoptRef(new ScrollingCoordinator(page));
 }
 
 ScrollingCoordinator::ScrollingCoordinator(Page* page)
     : m_page(page)
     , m_scrollGestureRegionIsDirty(false)
     , m_touchEventTargetRectsAreDirty(false)
     , m_wasFrameScrollable(false)
@@ skipping 150 matching lines @@
 }
 
 static void detachScrollbarLayer(GraphicsLayer* scrollbarGraphicsLayer)
 {
     ASSERT(scrollbarGraphicsLayer);
 
     scrollbarGraphicsLayer->setContentsToPlatformLayer(0);
     scrollbarGraphicsLayer->setDrawsContent(true);
 }
 
-static void setupScrollbarLayer(GraphicsLayer* scrollbarGraphicsLayer, WebScrollbarLayer* scrollbarLayer, WebLayer* scrollLayer)
+static void setupScrollbarLayer(GraphicsLayer* scrollbarGraphicsLayer, WebScrollbarLayer* scrollbarLayer, WebLayer* scrollLayer, WebLayer* containerLayer)
 {
     ASSERT(scrollbarGraphicsLayer);
     ASSERT(scrollbarLayer);
 
     if (!scrollLayer) {
         detachScrollbarLayer(scrollbarGraphicsLayer);
         return;
     }
     scrollbarLayer->setScrollLayer(scrollLayer);
+    scrollbarLayer->setClipLayer(containerLayer);
     scrollbarGraphicsLayer->setContentsToPlatformLayer(scrollbarLayer->layer());
     scrollbarGraphicsLayer->setDrawsContent(false);
 }
 
 WebScrollbarLayer* ScrollingCoordinator::addWebScrollbarLayer(ScrollableArea* scrollableArea, ScrollbarOrientation orientation, PassOwnPtr<blink::WebScrollbarLayer> scrollbarLayer)
 {
     ScrollbarMap& scrollbars = orientation == HorizontalScrollbar ? m_horizontalScrollbars : m_verticalScrollbars;
     return scrollbars.add(scrollableArea, scrollbarLayer).iterator->value.get();
 }
 
@@ skipping 45 matching lines @@
             scrollbarLayer = addWebScrollbarLayer(scrollableArea, orientation, webScrollbarLayer.release());
         }
 
         // Root layer non-overlay scrollbars should be marked opaque to disable
         // blending.
         bool isOpaqueScrollbar = !scrollbar->isOverlayScrollbar();
         if (!scrollbarGraphicsLayer->contentsOpaque())
             scrollbarGraphicsLayer->setContentsOpaque(isMainFrame && isOpaqueScrollbar);
         scrollbarLayer->layer()->setOpaque(scrollbarGraphicsLayer->contentsOpaque());
 
-        setupScrollbarLayer(scrollbarGraphicsLayer, scrollbarLayer, scrollingWebLayerForScrollableArea(scrollableArea));
+        WebLayer* scrollLayer = scrollingWebLayerForScrollableArea(scrollableArea);
+        WebLayer* containerLayer = containerWebLayerForScrollableArea(scrollableArea);
+        setupScrollbarLayer(scrollbarGraphicsLayer, scrollbarLayer, scrollLayer, containerLayer);
     } else
         removeWebScrollbarLayer(scrollableArea, orientation);
 }
 
 bool ScrollingCoordinator::scrollableAreaScrollLayerDidChange(ScrollableArea* scrollableArea)
 {
     GraphicsLayer* scrollLayer = scrollLayerForScrollableArea(scrollableArea);
     if (scrollLayer) {
         bool isMainFrame = isForMainFrame(scrollableArea);
         scrollLayer->setScrollableArea(scrollableArea, isMainFrame);
     }
 
     WebLayer* webLayer = scrollingWebLayerForScrollableArea(scrollableArea);
+    WebLayer* containerLayer = containerWebLayerForScrollableArea(scrollableArea);
     if (webLayer) {
+        // TODO(wjmaclean) Remove the next line once https://codereview.chromium.org/23983047 lands.
         webLayer->setScrollable(true);
+        webLayer->setScrollClipLayer(containerLayer);
         webLayer->setScrollPosition(IntPoint(scrollableArea->scrollPosition() - scrollableArea->minimumScrollPosition()));
+        // TODO(wjmaclean) Remove the next line once https://codereview.chromium.org/23983047 lands.
         webLayer->setMaxScrollPosition(IntSize(scrollableArea->scrollSize(HorizontalScrollbar), scrollableArea->scrollSize(VerticalScrollbar)));
+        webLayer->setBounds(scrollableArea->contentsSize());
         bool canScrollX = scrollableArea->userInputScrollable(HorizontalScrollbar);
         bool canScrollY = scrollableArea->userInputScrollable(VerticalScrollbar);
         webLayer->setUserScrollable(canScrollX, canScrollY);
     }
     if (WebScrollbarLayer* scrollbarLayer = getWebScrollbarLayer(scrollableArea, HorizontalScrollbar)) {
         GraphicsLayer* horizontalScrollbarLayer = horizontalScrollbarLayerForScrollableArea(scrollableArea);
         if (horizontalScrollbarLayer)
-            setupScrollbarLayer(horizontalScrollbarLayer, scrollbarLayer, webLayer);
+            setupScrollbarLayer(horizontalScrollbarLayer, scrollbarLayer, webLayer, containerLayer);
     }
     if (WebScrollbarLayer* scrollbarLayer = getWebScrollbarLayer(scrollableArea, VerticalScrollbar)) {
         GraphicsLayer* verticalScrollbarLayer = verticalScrollbarLayerForScrollableArea(scrollableArea);
         if (verticalScrollbarLayer)
-            setupScrollbarLayer(verticalScrollbarLayer, scrollbarLayer, webLayer);
+            setupScrollbarLayer(verticalScrollbarLayer, scrollbarLayer, webLayer, containerLayer);
     }
 
     return !!webLayer;
 }
 
 // In order to do a DFS cross-frame walk of the RenderLayer tree, we need to know which
 // RenderLayers have child frames inside of them. This computes a mapping for the
 // current frame which we can consult while walking the layers of that frame.
 // Whenever we descend into a new frame, a new map will be created.
 typedef HashMap<const RenderLayer*, Vector<const Frame*> > LayerFrameMap;
@@ skipping 554 matching lines @@
 }
 
 bool ScrollingCoordinator::frameViewIsScrollableIsDirty() const
 {
     FrameView* frameView = m_page->mainFrame()->view();
     bool frameIsScrollable = frameView && frameView->isScrollable();
     return frameIsScrollable != m_wasFrameScrollable;
 }
 
 } // namespace WebCore