ResizeObserver pt6: integration

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 17 matching lines @@
 #include "core/layout/api/LayoutItem.h"
 #include "core/layout/api/LayoutPartItem.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/DocumentLoader.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/RootScrollerController.h"
 #include "core/page/scrolling/RootViewportScrollCallback.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/paint/FramePainter.h"
@@ skipping 2420 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()

[esprehn, 2016/08/10 04:27:09]

Observers() I think you want plural?

[atotic1, 2016/08/10 18:25:33]

Done.

I usually keep everything singular for simplicity.

+{
+    // Controller exists only if ResizeObserver was created.
+    if (!frame().document()->resizeObserverController())
+        return;
+
+    ResizeObserverController& resizeController = m_frame->document()->ensureResizeObserverController();
+
+    DCHECK(lifecycle().state() >= DocumentLifecycle::LayoutClean);
+
+    size_t minDepth = 0;
+    for (minDepth = resizeController.gatherObservations(0);
+        minDepth != ResizeObserverController::kDepthBottom;
+        minDepth = resizeController.gatherObservations(minDepth)) {
+        resizeController.deliverObservations();
+        frame().document()->updateStyleAndLayout();
+    }
+
+    if (resizeController.skippedObservations()) {
+        resizeController.clearObservations();

[esprehn, 2016/08/10 04:27:09]

Hmm, if we clear the observations how does scheduling a frame below go about
calling all of the observers again?

[atotic1, 2016/08/10 18:25:33]

This is non-obvious.

ResizeObserver has a set of active observations.
gather/deliver/clear/skipped API operates on this set.

ResizeObserverController/ResizeObserver/ResizeObservation have "changed" flags. 

Active observations are regenerated for every event loop from a set of 
"changed" flags.

"changed" flags are only cleared when observations on deliver(), not on clear().

+        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();
+    }
+
+    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
@@ skipping 11 matching lines @@
     }
 
     updateStyleAndLayoutIfNeededRecursive();
     DCHECK(lifecycle().state() >= DocumentLifecycle::LayoutClean);
 
     if (targetState == DocumentLifecycle::LayoutClean) {
         updateViewportIntersectionsForSubtree(targetState);
         return;
     }
 
+    forAllNonThrottledFrameViews([](FrameView& frameView) {
+        frameView.notifyResizeObserver();

[esprehn, 2016/08/10 04:27:09]

Did you add some iframe tests where the new ResizeObserver call is inside the
iframe?

[atotic1, 2016/08/10 18:25:33]

observer.html, test6()

+    });
+
     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 1722 matching lines @@
 }
 
 bool FrameView::canThrottleRendering() const
 {
     if (!RuntimeEnabledFeatures::renderingPipelineThrottlingEnabled())
         return false;
     return m_subtreeThrottled || (m_hiddenForThrottling && m_crossOriginForThrottling);
 }
 
 } // namespace blink