DevTools: expose layer compositing reasons and paint count via layer tree agent

Source/core/inspector/InspectorLayerTreeAgent.cpp

 /*
  * Copyright (C) 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 28 matching lines @@
 #include "core/inspector/InspectorState.h"
 #include "core/inspector/InstrumentingAgents.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/page/Page.h"
 #include "core/platform/graphics/IntRect.h"
 #include "core/platform/graphics/transforms/TransformationMatrix.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderLayerBacking.h"
 #include "core/rendering/RenderLayerCompositor.h"
 #include "core/rendering/RenderView.h"
+#include "public/platform/WebCompositingReasons.h"
 #include "public/platform/WebLayer.h"
 
 namespace WebCore {
 
 namespace LayerTreeAgentState {
 static const char layerTreeAgentEnabled[] = "layerTreeAgentEnabled";
 };
 
 static PassRefPtr<TypeBuilder::LayerTree::Layer> buildObjectForLayer(GraphicsLayer* graphicsLayer, int nodeId, bool forceRoot)
 {
     RefPtr<TypeBuilder::LayerTree::Layer> layerObject = TypeBuilder::LayerTree::Layer::create()
         .setLayerId(String::number(graphicsLayer->platformLayer()->id()))
         .setNodeId(nodeId)
         .setOffsetX(graphicsLayer->position().x())
         .setOffsetY(graphicsLayer->position().y())
         .setWidth(graphicsLayer->size().width())
         .setHeight(graphicsLayer->size().height())
-        .setPaintCount(graphicsLayer->repaintCount());
+        .setPaintCount(graphicsLayer->paintCount());
 
-    // Artificially clip tree at root renger layer's graphic layer -- it might be not the real
-    // root of graphics layer hierarchy, as platform adds containing layers (e.g. for overflosw scroll).
-    if (graphicsLayer->parent() && !forceRoot)
-        layerObject->setParentLayerId(String::number(graphicsLayer->parent()->platformLayer()->id()));
-
+    // Artificially clip tree at root render layer's graphic layer -- it might be not the real
+    // root of graphics layer hierarchy, as platform adds containing layers (e.g. for frame scrolling).
+    if (!forceRoot) {
+        GraphicsLayer* parent = graphicsLayer->parent();
+        if (!parent)
+            parent = graphicsLayer->replicatedLayer();
+        if (parent)
+            layerObject->setParentLayerId(String::number(parent->platformLayer()->id()));
+    }
     const TransformationMatrix& transform = graphicsLayer->transform();
     if (!transform.isIdentity()) {
         TransformationMatrix::FloatMatrix4 flattenedMatrix;
         transform.toColumnMajorFloatArray(flattenedMatrix);
         RefPtr<TypeBuilder::Array<double> > transformArray = TypeBuilder::Array<double>::create();
         for (size_t i = 0; i < WTF_ARRAY_LENGTH(flattenedMatrix); ++i)
             transformArray->addItem(flattenedMatrix[i]);
         layerObject->setTransform(transformArray);
         const FloatPoint3D& anchor = graphicsLayer->anchorPoint();
         layerObject->setAnchorX(anchor.x());
@@ skipping 61 matching lines @@
 
 void InspectorLayerTreeAgent::layerTreeDidChange()
 {
     m_frontend->layerTreeDidChange();
 }
 
 void InspectorLayerTreeAgent::getLayers(ErrorString* errorString, const int* nodeId, RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::Layer> >& layers)
 {
     layers = TypeBuilder::Array<TypeBuilder::LayerTree::Layer>::create();
 
-    RenderView* renderView = m_page->mainFrame()->contentRenderer();
-    RenderLayerCompositor* compositor = renderView ? renderView->compositor() : 0;
-    if (!compositor) {
-        *errorString = "Not in compositing mode";
+    RenderLayerCompositor* compositor = renderLayerCompositor(errorString);
+    if (!compositor)
         return;
-    }
     if (!nodeId) {
         gatherLayersUsingRenderLayerHierarchy(errorString, compositor->rootRenderLayer(), layers);
         return;
     }
     Node* node = m_instrumentingAgents->inspectorDOMAgent()->nodeForId(*nodeId);
     if (!node) {
         *errorString = "Provided node id doesn't match any known node";
         return;
     }
     RenderObject* renderer = node->renderer();
     if (!renderer) {
         *errorString = "Node for provided node id doesn't have a renderer";
         return;
     }
     gatherLayersUsingRenderObjectHierarchy(errorString, renderer, layers);
 }
 
 void InspectorLayerTreeAgent::addRenderLayerBacking(ErrorString* errorString, RenderLayerBacking* layerBacking, Node* node, RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::Layer> >& layers)
 {
     int nodeId = idForNode(errorString, node);
-    RenderLayerCompositor* compositor = layerBacking->owningLayer()->compositor();
     bool forceRoot = layerBacking->owningLayer()->isRootLayer();
     if (layerBacking->ancestorClippingLayer()) {
         maybeAddGraphicsLayer(layerBacking->ancestorClippingLayer(), nodeId, layers, forceRoot);
         forceRoot = false;
     }
     maybeAddGraphicsLayer(layerBacking->graphicsLayer(), nodeId, layers, forceRoot);
     maybeAddGraphicsLayer(layerBacking->clippingLayer(), nodeId, layers);
     maybeAddGraphicsLayer(layerBacking->foregroundLayer(), nodeId, layers);
     maybeAddGraphicsLayer(layerBacking->backgroundLayer(), nodeId, layers);
     maybeAddGraphicsLayer(layerBacking->scrollingLayer(), nodeId, layers);
@@ skipping 27 matching lines @@
 {
     InspectorDOMAgent* domAgent = m_instrumentingAgents->inspectorDOMAgent();
 
     int nodeId = domAgent->boundNodeId(node);
     if (!nodeId)
         nodeId = domAgent->pushNodeToFrontend(errorString, domAgent->boundNodeId(node->document()), node);
 
     return nodeId;
 }
 
+RenderLayerCompositor* InspectorLayerTreeAgent::renderLayerCompositor(ErrorString* errorString)
+{
+    RenderView* renderView = m_page->mainFrame()->contentRenderer();
+    RenderLayerCompositor* compositor = renderView ? renderView->compositor() : 0;
+    if (!compositor)
+        *errorString = "Not in the compositing mode";
+    return compositor;
+}
+
+static GraphicsLayer* findLayerById(GraphicsLayer* root, int layerId)
+{
+    if (root->platformLayer()->id() == layerId)
+        return root;
+    for (size_t i = 0, size = root->children().size(); i < size; ++i) {
+        if (GraphicsLayer* layer = findLayerById(root->children()[i], layerId))
+            return layer;
+    }
+    return 0;
+}
+
+GraphicsLayer* InspectorLayerTreeAgent::layerById(ErrorString* errorString, const String& layerId)
+{
+    bool ok;
+    int id = layerId.toInt(&ok);
+    if (!ok) {
+        *errorString = "Invalid layer id";
+        return 0;
+    }
+    RenderLayerCompositor* compositor = renderLayerCompositor(errorString);
+    if (!compositor)
+        return 0;
+
+    GraphicsLayer* result = findLayerById(compositor->rootGraphicsLayer(), id);
+    if (!result)
+        *errorString = "No layer matching given id found";
+    return result;
+}
+
+struct CompositingReasonToProtocolName {
+    uint64_t mask;
+    const char *protocolName;
+};
+
+
+void InspectorLayerTreeAgent::compositingReasons(ErrorString* errorString, const String& layerId, RefPtr<TypeBuilder::Array<String> >& reasonStrings)
+{
+    static CompositingReasonToProtocolName compositingReasonNames[] = {
+        { CompositingReason3DTransform, "transform3D" },
+        { CompositingReasonVideo, "video" },
+        { CompositingReasonCanvas, "canvas" },
+        { CompositingReasonPlugin, "plugin" },
+        { CompositingReasonIFrame, "iFrame" },
+        { CompositingReasonBackfaceVisibilityHidden, "backfaceVisibilityHidden" },
+        { CompositingReasonAnimation, "animation" },
+        { CompositingReasonFilters, "filters" },
+        { CompositingReasonPositionFixed, "positionFixed" },
+        { CompositingReasonPositionSticky, "positionSticky" },
+        { CompositingReasonOverflowScrollingTouch, "overflowScrollingTouch" },
+        { CompositingReasonAssumedOverlap, "assumedOverlap" },
+        { CompositingReasonOverlap, "overlap" },
+        { CompositingReasonNegativeZIndexChildren, "negativeZIndexChildren" },
+        { CompositingReasonTransformWithCompositedDescendants, "transformWithCompositedDescendants" },
+        { CompositingReasonOpacityWithCompositedDescendants, "opacityWithCompositedDescendants" },
+        { CompositingReasonMaskWithCompositedDescendants, "maskWithCompositedDescendants" },
+        { CompositingReasonReflectionWithCompositedDescendants, "reflectionWithCompositedDescendants" },
+        { CompositingReasonFilterWithCompositedDescendants, "filterWithCompositedDescendants" },
+        { CompositingReasonBlendingWithCompositedDescendants, "blendingWithCompositedDescendants" },
+        { CompositingReasonClipsCompositingDescendants, "clipsCompositingDescendants" },
+        { CompositingReasonPerspective, "perspective" },
+        { CompositingReasonPreserve3D, "preserve3D" },
+        { CompositingReasonRoot, "root" },
+        { CompositingReasonLayerForClip, "layerForClip" },
+        { CompositingReasonLayerForScrollbar, "layerForScrollbar" },
+        { CompositingReasonLayerForScrollingContainer, "layerForScrollingContainer" },
+        { CompositingReasonLayerForForeground, "layerForForeground" },
+        { CompositingReasonLayerForBackground, "layerForBackground" },
+        { CompositingReasonLayerForMask, "layerForMask" },
+        { CompositingReasonLayerForVideoOverlay, "layerForVideoOverlay" }
+    };
+
+    const GraphicsLayer* graphicsLayer = layerById(errorString, layerId);
+    if (!graphicsLayer)
+        return;
+    WebKit::WebCompositingReasons reasonsBitmask = graphicsLayer->compositingReasons();
+    reasonStrings = TypeBuilder::Array<String>::create();
+    for (size_t i = 0; i < WTF_ARRAY_LENGTH(compositingReasonNames); ++i) {
+        if (!(reasonsBitmask & compositingReasonNames[i].mask))
+            continue;
+        reasonStrings->addItem(compositingReasonNames[i].protocolName);
+#ifndef _NDEBUG
+        reasonsBitmask &= ~compositingReasonNames[i].mask;
+#endif
+    }
+    ASSERT(!reasonsBitmask);
+}
+
 } // namespace WebCore