Intersection Observer support for OOPIF

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 34 matching lines @@
 #include "core/editing/markers/DocumentMarkerController.h"
 #include "core/events/ErrorEvent.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/frame/BrowserControls.h"
 #include "core/frame/EventHandlerRegistry.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Location.h"
 #include "core/frame/PageScaleConstraintsSet.h"
 #include "core/frame/PerformanceMonitor.h"
+#include "core/frame/RemoteFrame.h"
+#include "core/frame/RemoteFrameView.h"
 #include "core/frame/Settings.h"
 #include "core/frame/VisualViewport.h"
 #include "core/html/HTMLFrameElement.h"
 #include "core/html/HTMLPlugInElement.h"
 #include "core/html/TextControlElement.h"
 #include "core/html/parser/TextResourceDecoder.h"
 #include "core/input/EventHandler.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/inspector/InspectorTraceEvents.h"
 #include "core/layout/LayoutAnalyzer.h"
@@ skipping 122 matching lines @@
       m_hiddenForThrottling(false),
       m_subtreeThrottled(false),
       m_lifecycleUpdatesThrottled(false),
       m_needsPaintPropertyUpdate(true),
       m_currentUpdateLifecyclePhasesTargetState(
           DocumentLifecycle::Uninitialized),
       m_scrollAnchor(this),
       m_scrollbarManager(*this),
       m_needsScrollbarsUpdate(false),
       m_suppressAdjustViewSize(false),
-      m_allowsLayoutInvalidationAfterLayoutClean(true) {
+      m_allowsLayoutInvalidationAfterLayoutClean(true),
+      m_remoteViewportIntersection(0, 0, 0, 0) {
   init();
 }
 
 FrameView* FrameView::create(LocalFrame& frame) {
   FrameView* view = new FrameView(frame);
   view->show();
   return view;
 }
 
 FrameView* FrameView::create(LocalFrame& frame, const IntSize& initialSize) {
@@ skipping 4464 matching lines @@
 int FrameView::initialViewportWidth() const {
   DCHECK(m_frame->isMainFrame());
   return m_initialViewportSize.width();
 }
 
 int FrameView::initialViewportHeight() const {
   DCHECK(m_frame->isMainFrame());
   return m_initialViewportSize.height();
 }
 
+void FrameView::setViewportIntersectionFromParent(
+    const IntRect& viewportIntersection) {
+  if (m_remoteViewportIntersection != viewportIntersection) {
+    m_remoteViewportIntersection = viewportIntersection;
+    scheduleAnimation();
+  }
+}
+
+IntRect FrameView::remoteViewportIntersection() {
+  IntRect intersection(m_remoteViewportIntersection);
+  intersection.move(scrollOffsetInt());
+  return intersection;
+}
+
+void FrameView::mapQuadToAncestorFrameIncludingScrollOffset(
+    LayoutRect& rect,
+    const LayoutObject* descendant,
+    const LayoutView* ancestor,
+    MapCoordinatesFlags mode) {
+  FloatQuad mappedQuad = descendant->localToAncestorQuad(
+      FloatQuad(FloatRect(rect)), ancestor, mode);
+  rect = LayoutRect(mappedQuad.boundingBox());
+
+  // localToAncestorQuad accounts for scroll offset if it encounters a remote
+  // frame in the ancestor chain, otherwise it needs to be added explicitly.
+  if (frame().localFrameRoot() == frame().tree().top() ||
+      (ancestor && ancestor->frame() != frame().tree().top())) {

[szager1, 2016/12/16 03:42:34]

I think the 'ancestor->frame() != frame().tree().top()' is not right.  I think
it should just be:

if (ancestor || frame().localFrameRoot() == frame().tree().top())

Even if ancestor->frame() is not the top frame, its scroll offset still will not
be applied by LayoutView::maplocalToAncestor, so it needs to be subtracted here.

[kenrb, 2016/12/16 16:17:35]

I think that situation is covered, because this evaluates to true if the
ancestor frame is not the top frame.

One of the things I am trying to account for is if the main frame is local, but
there is a remote frame in the tree in between the current frame and the top. In
that case, mapLocalToAncestor acts the same as if the main frame is remote, but
it is possible that it could be called with a non-null ancestor.

That said, I have made a small improvement to the condition in the next patch
set.

+    FrameView* ancestorView =
+        (ancestor ? ancestor->frameView()
+                  : toLocalFrame(frame().tree().top())->view());
+    LayoutSize scrollPosition = LayoutSize(ancestorView->getScrollOffset());
+    rect.move(-scrollPosition);
+  }
+}
+
 }  // namespace blink