Initial ResizeObserver implementation

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 20 matching lines @@
 #include "core/css/FontFaceSet.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/dom/AXObjectCache.h"
 #include "core/dom/DOMNodeIds.h"
 #include "core/dom/Fullscreen.h"
 #include "core/dom/IntersectionObserverController.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/FrameSelection.h"
 #include "core/editing/RenderedPosition.h"
 #include "core/editing/markers/DocumentMarkerController.h"
+#include "core/events/ErrorEvent.h"
 #include "core/fetch/ResourceFetcher.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/Settings.h"
 #include "core/frame/TopControls.h"
 #include "core/frame/VisualViewport.h"
 #include "core/html/HTMLFrameElement.h"
@@ skipping 15 matching lines @@
 #include "core/layout/TracedLayoutObject.h"
 #include "core/layout/api/LayoutBoxModel.h"
 #include "core/layout/api/LayoutItem.h"
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/layout/compositing/CompositedLayerMapping.h"
 #include "core/layout/compositing/CompositedSelection.h"
 #include "core/layout/compositing/PaintLayerCompositor.h"
 #include "core/layout/svg/LayoutSVGRoot.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderClient.h"
+#include "core/observer/ResizeObserverController.h"
 #include "core/page/AutoscrollController.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/FocusController.h"
 #include "core/page/FrameTree.h"
 #include "core/page/Page.h"
 #include "core/page/scrolling/ChildViewportScrollCallback.h"
 #include "core/page/scrolling/RootViewportScrollCallback.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/paint/FramePainter.h"
 #include "core/paint/PaintLayer.h"
@@ skipping 2412 matching lines @@
 {
     LocalFrame* localFrameRoot = frame().localFrameRoot();
     if (localFrameRoot->view()->m_currentUpdateLifecyclePhasesTargetState < DocumentLifecycle::PaintInvalidationClean
         || lifecycle().state() >= DocumentLifecycle::PrePaintClean) {
         // Schedule visual update to process the paint invalidation in the next cycle.
         localFrameRoot->scheduleVisualUpdateUnlessThrottled();
     }
     // Otherwise the paint invalidation will be handled in paint invalidation phase of this cycle.
 }
 
+void FrameView::notifyResizeObserver()
+{
+    if (!m_frame->document()->resizeObserverController())

[eae, 2016/07/13 23:39:47]

When would notifyResizeObserver ever be called if the document doesn't have a
resizeObserverController? A comment explaining the edge case would be helpful!

[atotic1, 2016/07/15 01:43:17]

Controller is allocated only if ResizeObserver is created. This is a common
case.

+        return;
+
+    ResizeObserverController& resizeController = m_frame->document()->ensureResizeObserverController();
+
+    DCHECK(lifecycle().state() >= DocumentLifecycle::LayoutClean);
+
+    size_t resizeNotifyCount = 0;
+
+    while (resizeController.gatherObservations()) {
+        if (++resizeNotifyCount > ResizeObserverController::kRenderLoopLimit) {
+            resizeController.clearObservations();
+            // Report the error.

[eae, 2016/07/13 23:39:47]

Please remove redundant comment.

[atotic1, 2016/07/15 01:43:17]

Done.

+            ErrorEvent * error = ErrorEvent::create("ResizeObserver loop limit exceeded", SourceLocation::capture(m_frame->document()), nullptr);
+            m_frame->document()->reportException(error, NotSharableCrossOrigin);
+            // Ensure notifications will get delivered in next cycle.
+            if (FrameView* frameView = m_frame->view())
+                frameView->scheduleAnimation();
+            break;
+        }
+
+        resizeController.deliverObservations();
+
+        if (lifecycle().state() < DocumentLifecycle::LayoutClean || layoutView()->needsLayout())
+            updateStyleAndLayoutIfNeededRecursive();
+    }
+
+    DCHECK(!layoutView()->needsLayout());
+}
+
 // TODO(leviw): We don't assert lifecycle information from documents in child PluginViews.
 void FrameView::updateLifecyclePhasesInternal(DocumentLifecycle::LifecycleState targetState)
 {
     // This must be called from the root frame, since it recurses down, not up.
     // Otherwise the lifecycles of the frames might be out of sync.
     DCHECK(m_frame->isLocalRoot());
 
     // Only the following target states are supported.
     DCHECK(targetState == DocumentLifecycle::LayoutClean
         || targetState == DocumentLifecycle::CompositingClean
         || targetState == DocumentLifecycle::PrePaintClean
         || targetState == DocumentLifecycle::PaintClean);
 
     TemporaryChange<DocumentLifecycle::LifecycleState> targetStateScope(m_currentUpdateLifecyclePhasesTargetState, targetState);
 
     if (shouldThrottleRendering()) {
         updateViewportIntersectionsForSubtree(std::min(targetState, DocumentLifecycle::CompositingClean));
         return;
     }
 
     updateStyleAndLayoutIfNeededRecursive();
     DCHECK(lifecycle().state() >= DocumentLifecycle::LayoutClean);
 
     if (targetState == DocumentLifecycle::LayoutClean) {
         updateViewportIntersectionsForSubtree(targetState);
         return;
     }
 
+    notifyResizeObserver();
+
     if (LayoutViewItem view = layoutViewItem()) {
         forAllNonThrottledFrameViews([](FrameView& frameView) {
             frameView.checkDoesNotNeedLayout();
             frameView.m_allowsLayoutInvalidationAfterLayoutClean = false;
         });
 
         {
             TRACE_EVENT1("devtools.timeline", "UpdateLayerTree", "data", InspectorUpdateLayerTreeEvent::data(m_frame.get()));
 
             // This was required for slimming paint v1 but is only temporarily
@@ skipping 1712 matching lines @@
     return m_subtreeThrottled || (m_hiddenForThrottling && m_crossOriginForThrottling);
 }
 
 LayoutBox& FrameView::boxForScrollControlPaintInvalidation() const
 {
     ASSERT(!layoutViewItem().isNull());
     return *layoutView();
 }
 
 } // namespace blink