Expand PaintLayer clip to account for hidden URL bar with document.rootScroller

third_party/WebKit/Source/core/paint/PaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights
  * reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 31 matching lines @@
  * version of this file under any of the LGPL, the MPL or the GPL.
  */
 
 #include "core/paint/PaintLayer.h"
 
 #include "core/CSSPropertyNames.h"
 #include "core/HTMLNames.h"
 #include "core/css/PseudoStyleRequest.h"
 #include "core/dom/Document.h"
 #include "core/dom/shadow/ShadowRoot.h"
+#include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/layout/FragmentainerIterator.h"
 #include "core/layout/HitTestRequest.h"
 #include "core/layout/HitTestResult.h"
 #include "core/layout/HitTestingTransformState.h"
 #include "core/layout/LayoutFlowThread.h"
 #include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutPart.h"
 #include "core/layout/LayoutTreeAsText.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/api/LayoutPartItem.h"
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/layout/compositing/CompositedLayerMapping.h"
 #include "core/layout/compositing/PaintLayerCompositor.h"
 #include "core/layout/svg/LayoutSVGResourceClipper.h"
 #include "core/layout/svg/LayoutSVGRoot.h"
 #include "core/page/Page.h"
 #include "core/page/scrolling/RootScrollerController.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
+#include "core/page/scrolling/TopDocumentRootScrollerController.h"
 #include "core/paint/BoxReflectionUtils.h"
 #include "core/paint/FilterEffectBuilder.h"
 #include "core/paint/ObjectPaintInvalidator.h"
 #include "platform/LengthFunctions.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/FloatPoint3D.h"
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/TransformState.h"
 #include "platform/graphics/CompositorFilterOperations.h"
 #include "platform/graphics/filters/Filter.h"
@@ skipping 122 matching lines @@
 }
 
 String PaintLayer::debugName() const {
   return layoutObject()->debugName();
 }
 
 LayoutRect PaintLayer::visualRect() const {
   return m_layoutObject->visualRect();
 }
 
+bool PaintLayer::isRootScrollerLayer() const {
+  return this ==
+         layoutObject()
+             ->document()
+             .rootScrollerController()
+             .rootScrollerPaintLayer();
+}
+
 PaintLayerCompositor* PaintLayer::compositor() const {
   if (!layoutObject()->view())
     return 0;
   return layoutObject()->view()->compositor();
 }
 
 void PaintLayer::contentChanged(ContentChangeType changeType) {
   // updateLayerCompositingState will query compositingReasons for accelerated
   // overflow scrolling.  This is tripped by
   // LayoutTests/compositing/content-changed-chicken-egg.html
@@ skipping 1468 matching lines @@
     fragment.intersect(fragment.paginationClip);
 
     // TODO(mstensho): Don't add empty fragments. We've always done that in some
     // cases, but there should be no reason to do so. Either filter them out
     // here, or, even better: pass a better clip rectangle to the fragmentainer
     // iterator, so that we won't end up with empty fragments here.
     fragments.push_back(fragment);
   }
 }
 
-static inline LayoutRect frameVisibleRect(LayoutObject* layoutObject) {
-  FrameView* frameView = layoutObject->document().view();
+static inline LayoutRect frameVisibleRect(PaintLayer* layer) {
+  LayoutObject* layoutObject = layer->layoutObject();
+  DCHECK(layoutObject);
+
+  Document& doc = layoutObject->document();
+
+  FrameView* frameView = doc.view();
   if (!frameView)
     return LayoutRect();
 
-  return LayoutRect(frameView->visibleContentRect());
+  IntRect frameRect = frameView->visibleContentRect(ExcludeScrollbars);
+
+  FrameHost* host = doc.frameHost();
+  DCHECK(host);
+  if (host->globalRootScrollerController().isRootScrollerAncestor(doc)) {

[chrishtr, 2017/01/21 02:06:47]

This adjustment in hit-testing code doesn't also appear in in LayoutBox.
Why not?

+    frameRect.setSize(host->globalRootScrollerController()
+                          .visibleContentRect(ExcludeScrollbars)
+                          .size());
+  }
+
+  return LayoutRect(frameRect);
 }
 
 bool PaintLayer::hitTest(HitTestResult& result) {
   DCHECK(isSelfPaintingLayer() || hasSelfPaintingLayerDescendant());
 
   // LayoutView should make sure to update layout before entering hit testing
   DCHECK(!layoutObject()->frame()->view()->layoutPending());
   DCHECK(!layoutObject()->document().layoutViewItem().needsLayout());
 
   const HitTestRequest& request = result.hitTestRequest();
   const HitTestLocation& hitTestLocation = result.hitTestLocation();
 
   // Start with frameVisibleRect to ensure we include the scrollbars.
-  LayoutRect hitTestArea = frameVisibleRect(layoutObject());
+  LayoutRect hitTestArea = frameVisibleRect(this);
   if (request.ignoreClipping())
     hitTestArea.unite(LayoutRect(layoutObject()->view()->documentRect()));
 
   PaintLayer* insideLayer =
       hitTestLayer(this, 0, result, hitTestArea, hitTestLocation, false);
   if (!insideLayer && isRootLayer()) {
     IntRect hitRect = hitTestLocation.boundingBox();
     bool fallback = false;
     // If we didn't hit any layers but are still inside the document
     // bounds, then we should fallback to hitting the document.
@@ skipping 1488 matching lines @@
 }
 
 void showLayerTree(const blink::LayoutObject* layoutObject) {
   if (!layoutObject) {
     LOG(INFO) << "Cannot showLayerTree. Root is (nil)";
     return;
   }
   showLayerTree(layoutObject->enclosingLayer());
 }
 #endif