Intersection Observer support for OOPIF

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/RemoteFrameView.h"
 
+#include "core/dom/IntersectionObserverEntry.h"
 #include "core/frame/FrameView.h"
+#include "core/frame/LocalFrame.h"
 #include "core/frame/RemoteFrame.h"
+#include "core/frame/RemoteFrameClient.h"
 #include "core/html/HTMLFrameOwnerElement.h"
+#include "core/layout/LayoutView.h"
 #include "core/layout/api/LayoutPartItem.h"
 
 namespace blink {
 
 RemoteFrameView::RemoteFrameView(RemoteFrame* remoteFrame)
     : m_remoteFrame(remoteFrame) {
   ASSERT(remoteFrame);
 }
 
 RemoteFrameView::~RemoteFrameView() {}
 
 void RemoteFrameView::setParent(Widget* parent) {
   Widget::setParent(parent);
   frameRectsChanged();
 }
 
 RemoteFrameView* RemoteFrameView::create(RemoteFrame* remoteFrame) {
   RemoteFrameView* view = new RemoteFrameView(remoteFrame);
   view->show();
   return view;
 }
 
+void RemoteFrameView::updateRemoteViewportIntersection() {
+  if (!m_remoteFrame->tree().parent() ||
+      !m_remoteFrame->tree().parent()->isLocalFrame() ||
+      !m_remoteFrame->client() || !m_remoteFrame->ownerLayoutObject())

[dcheng, 2017/01/05 07:10:19]

Can this be simplified to just checking if it has an ownerLayoutObject()? I
think the last condition being true should imply all the others.

[kenrb, 2017/01/09 19:31:20]

Done. I had concern with lifetime issues here, since this can get called while a
frame is getting detached from the tree, but if you are satisfied with this as
an invariant then I'm fine to simplify the check.

+    return;
+
+  FrameView* localRootView =
+      toLocalFrame(m_remoteFrame->tree().parent())->localFrameRoot()->view();
+  if (!localRootView)
+    return;
+
+  // Start with rect in remote frame's coordinate space. Then
+  // mapToVisualRectInAncestorSpace will move it to the local root's coordinate
+  // space and account for any clip from containing elements such as a
+  // scrollable div. Passing nullptr as an argument to
+  // mapToVisualRectInAncestorSpace causes it to be clipped to the viewport,
+  // even if there are RemoteFrame ancestors in the frame tree.
+  LayoutRect rect(0, 0, frameRect().width(), frameRect().height());
+  rect.move(m_remoteFrame->ownerLayoutObject()->contentBoxOffset());
+  if (!m_remoteFrame->ownerLayoutObject()->mapToVisualRectInAncestorSpace(
+          nullptr, rect))
+    return;
+  IntRect rootVisibleRect = localRootView->visibleContentRect();
+  IntRect viewportIntersection(rect);
+  viewportIntersection.intersect(rootVisibleRect);
+  viewportIntersection.move(-localRootView->scrollOffsetInt());
+
+  // Translate the intersection rect from the root frame's coordinate space
+  // to the remote frame's coordinate space.
+  viewportIntersection = convertFromRootFrame(viewportIntersection);
+  if (viewportIntersection != m_lastViewportIntersection) {
+    m_remoteFrame->client()->updateRemoteViewportIntersection(
+        viewportIntersection);
+  }
+  m_lastViewportIntersection = viewportIntersection;
+}
+
 void RemoteFrameView::dispose() {
   HTMLFrameOwnerElement* ownerElement = m_remoteFrame->deprecatedLocalOwner();
   // ownerElement can be null during frame swaps, because the
   // RemoteFrameView is disconnected before detachment.
   if (ownerElement && ownerElement->ownedWidget() == this)
     ownerElement->setWidget(nullptr);
   Widget::dispose();
 }
 
 void RemoteFrameView::invalidateRect(const IntRect& rect) {
@@ skipping 19 matching lines @@
 }
 
 void RemoteFrameView::frameRectsChanged() {
   // Update the rect to reflect the position of the frame relative to the
   // containing local frame root. The position of the local root within
   // any remote frames, if any, is accounted for by the embedder.
   IntRect newRect = frameRect();
   if (parent() && parent()->isFrameView())
     newRect = parent()->convertToRootFrame(
         toFrameView(parent())->contentsToFrame(newRect));
-  m_remoteFrame->frameRectsChanged(newRect);
+  m_remoteFrame->client()->frameRectsChanged(newRect);
+
+  updateRemoteViewportIntersection();
 }
 
 void RemoteFrameView::hide() {
   setSelfVisible(false);
 
   Widget::hide();
 
-  m_remoteFrame->visibilityChanged(false);
+  if (m_remoteFrame->client())
+    m_remoteFrame->client()->visibilityChanged(false);

[dcheng, 2017/01/05 07:10:19]

How come these need to null check while frameRectsChanged() doesn't? Do we call
this on something that's detached?

[kenrb, 2017/01/09 19:31:20]

The checks on RemoteFrame::visibilityChanged() were in that method's initial
version from a year ago, but I don't see any problem running without them so I
have taken them out.

 }
 
 void RemoteFrameView::show() {
   setSelfVisible(true);
 
   Widget::show();
 
-  m_remoteFrame->visibilityChanged(true);
+  if (m_remoteFrame->client())
+    m_remoteFrame->client()->visibilityChanged(true);
 }
 
 void RemoteFrameView::setParentVisible(bool visible) {
   if (isParentVisible() == visible)
     return;
 
   Widget::setParentVisible(visible);
   if (!isSelfVisible())
     return;
 
-  m_remoteFrame->visibilityChanged(isVisible());
+  if (m_remoteFrame->client())
+    m_remoteFrame->client()->visibilityChanged(isVisible());
 }
 
 DEFINE_TRACE(RemoteFrameView) {
   visitor->trace(m_remoteFrame);
   Widget::trace(visitor);
 }
 
 }  // namespace blink