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

Source/core/inspector/InspectorLayerTreeAgent.cpp

Index: Source/core/inspector/InspectorLayerTreeAgent.cpp
diff --git a/Source/core/inspector/InspectorLayerTreeAgent.cpp b/Source/core/inspector/InspectorLayerTreeAgent.cpp
index 3a7ab1d5bfb8b7d41f89ed3032ac25c87844b005..722964d7c43d9575e2a9c12c6d4823cf9208e5ba 100644
--- a/Source/core/inspector/InspectorLayerTreeAgent.cpp
+++ b/Source/core/inspector/InspectorLayerTreeAgent.cpp
@@ -46,6 +46,7 @@
 #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 {
@@ -63,13 +64,17 @@ static PassRefPtr<TypeBuilder::LayerTree::Layer> buildObjectForLayer(GraphicsLay
         .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).

[trchen, 2013/08/22 23:02:35]

I knew you didn't add this, but this comment is full of typos. :(

s/renger layer/render layer/
s/overflosw scroll/frame scrolling/

-    if (graphicsLayer->parent() && !forceRoot)
-        layerObject->setParentLayerId(String::number(graphicsLayer->parent()->platformLayer()->id()));
-
+    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;
@@ -151,8 +156,7 @@ void InspectorLayerTreeAgent::getLayers(ErrorString* errorString, const int* nod
 {
     layers = TypeBuilder::Array<TypeBuilder::LayerTree::Layer>::create();
 
-    RenderView* renderView = m_page->mainFrame()->contentRenderer();
-    RenderLayerCompositor* compositor = renderView ? renderView->compositor() : 0;
+    RenderLayerCompositor* compositor = renderLayerCompositor(errorString);
     if (!compositor) {
         *errorString = "Not in compositing mode";

[trchen, 2013/08/22 23:02:35]

errorString is already set.

         return;
@@ -177,7 +181,7 @@ void InspectorLayerTreeAgent::getLayers(ErrorString* errorString, const int* nod
 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();
+    RenderLayerCompositor* compositor = renderLayerCompositor(errorString);

[trchen, 2013/08/22 23:02:35]

Unused. Can we remove this variable?

     bool forceRoot = layerBacking->owningLayer()->isRootLayer();
     if (layerBacking->ancestorClippingLayer()) {
         maybeAddGraphicsLayer(layerBacking->ancestorClippingLayer(), nodeId, layers, forceRoot);
@@ -225,4 +229,142 @@ int InspectorLayerTreeAgent::idForNode(ErrorString* errorString, Node* 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;
+}
+
+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;
+    Vector<std::pair<GraphicsLayer*, size_t> > stack;

[trchen, 2013/08/22 23:02:35]

Any reason why not use recursion here?

+    stack.append(std::make_pair(compositor->rootGraphicsLayer(), 0));
+    while (!stack.isEmpty()) {
+        GraphicsLayer* layer = stack.last().first;
+        size_t& childIndex = stack.last().second;
+        if (childIndex < layer->children().size()) {
+            stack.append(std::make_pair(layer->children()[childIndex], 0));
+            childIndex++;
+            continue;
+        }
+        if (layer->platformLayer()->id() == id)
+            return layer;
+        stack.removeLast();
+    }
+    *errorString = "No layer matching given id found";
+    return 0;
+}
+
+void InspectorLayerTreeAgent::reasonsForCompositingLayer(ErrorString* errorString, const String& layerId, RefPtr<TypeBuilder::LayerTree::CompositingReasons>& compositingReasons)
+{
+    const GraphicsLayer* graphicsLayer = layerById(errorString, layerId);
+    if (!graphicsLayer)
+        return;
+
+    WebKit::WebCompositingReasons reasonsBitmask = graphicsLayer->compositingReasons();
+    compositingReasons = TypeBuilder::LayerTree::CompositingReasons::create();
+
+    if (reasonsBitmask & CompositingReason3DTransform)
+        compositingReasons->setTransform3D(true);
+
+    if (reasonsBitmask & CompositingReasonVideo)
+        compositingReasons->setVideo(true);
+    else if (reasonsBitmask & CompositingReasonCanvas)
+        compositingReasons->setCanvas(true);
+    else if (reasonsBitmask & CompositingReasonPlugin)
+        compositingReasons->setPlugin(true);
+    else if (reasonsBitmask & CompositingReasonIFrame)
+        compositingReasons->setIFrame(true);
+
+    if (reasonsBitmask & CompositingReasonBackfaceVisibilityHidden)
+        compositingReasons->setBackfaceVisibilityHidden(true);
+
+    if (reasonsBitmask & CompositingReasonAnimation)
+        compositingReasons->setAnimation(true);
+
+    if (reasonsBitmask & CompositingReasonFilters)
+        compositingReasons->setFilters(true);
+
+    if (reasonsBitmask & CompositingReasonPositionFixed)
+        compositingReasons->setPositionFixed(true);
+
+    if (reasonsBitmask & CompositingReasonPositionSticky)
+        compositingReasons->setPositionSticky(true);
+
+    if (reasonsBitmask & CompositingReasonOverflowScrollingTouch)
+        compositingReasons->setOverflowScrollingTouch(true);
+
+    if (reasonsBitmask & CompositingReasonAssumedOverlap)
+        compositingReasons->setAssumedOverlap(true);
+
+    if (reasonsBitmask & CompositingReasonOverlap)
+        compositingReasons->setOverlap(true);
+
+    if (reasonsBitmask & CompositingReasonNegativeZIndexChildren)
+        compositingReasons->setNegativeZIndexChildren(true);
+
+    if (reasonsBitmask & CompositingReasonTransformWithCompositedDescendants)
+        compositingReasons->setTransformWithCompositedDescendants(true);
+
+    if (reasonsBitmask & CompositingReasonOpacityWithCompositedDescendants)
+        compositingReasons->setOpacityWithCompositedDescendants(true);
+
+    if (reasonsBitmask & CompositingReasonMaskWithCompositedDescendants)
+        compositingReasons->setMaskWithCompositedDescendants(true);
+
+    if (reasonsBitmask & CompositingReasonReflectionWithCompositedDescendants)
+        compositingReasons->setReflectionWithCompositedDescendants(true);
+
+    if (reasonsBitmask & CompositingReasonFilterWithCompositedDescendants)
+        compositingReasons->setFilterWithCompositedDescendants(true);
+
+    if (reasonsBitmask & CompositingReasonBlendingWithCompositedDescendants)
+        compositingReasons->setBlendingWithCompositedDescendants(true);
+
+    if (reasonsBitmask & CompositingReasonClipsCompositingDescendants)
+        compositingReasons->setClipsCompositingDescendants(true);
+
+    if (reasonsBitmask & CompositingReasonPerspective)
+        compositingReasons->setPerspective(true);
+
+    if (reasonsBitmask & CompositingReasonPreserve3D)
+        compositingReasons->setPreserve3D(true);
+
+    if (reasonsBitmask & CompositingReasonRoot)
+        compositingReasons->setRoot(true);
+
+    if (reasonsBitmask & CompositingReasonLayerForClip)
+        compositingReasons->setLayerForClip(true);
+
+    if (reasonsBitmask & CompositingReasonLayerForScrollbar)
+        compositingReasons->setLayerForScrollbar(true);
+
+    if (reasonsBitmask & CompositingReasonLayerForScrollingContainer)
+        compositingReasons->setLayerForScrollingContainer(true);
+
+    if (reasonsBitmask & CompositingReasonLayerForForeground)
+        compositingReasons->setLayerForForeground(true);
+
+    if (reasonsBitmask & CompositingReasonLayerForBackground)
+        compositingReasons->setLayerForBackground(true);
+
+    if (reasonsBitmask & CompositingReasonLayerForMask)
+        compositingReasons->setLayerForMask(true);
+
+    if (reasonsBitmask & CompositingReasonLayerForVideoOverlay)
+        compositingReasons->setLayerForVideoOverlay(true);
+}
+
 } // namespace WebCore