Added showing slow scroll rectangles in Layers panel.

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 55 matching lines @@
     }
     int layerId;
     RefPtr<GraphicsContextSnapshot> graphicsSnapshot;
 };
 
 inline String idForLayer(const GraphicsLayer* graphicsLayer)
 {
     return String::number(graphicsLayer->platformLayer()->id());
 }
 
+static void buildRegionObjects(const blink::WebVector<blink::WebRect>& regions,

[pfeldman, 2014/02/28 07:43:43]

Builders return objects: we have buildObjectFor and buildArrayFor that return
object and array. This one is rather populateRects, but I'd simply do
buildScrollRect(rect, type) and populate single list below using two for loops.

(Region is a CSS term, you probably want a different name.)

[malch, 2014/02/28 12:19:57]

Done.

+    TypeBuilder::Array<TypeBuilder::LayerTree::ScrollRect>& scrollRects,
+    const TypeBuilder::LayerTree::ScrollRect::Type::Enum& type,
+    const TypeBuilder::LayerTree::LayerId& layerId)

[pfeldman, 2014/02/28 07:43:43]

Looks like this is unused.

[malch, 2014/02/28 12:19:57]

Done.

+{
+    for (size_t i = 0; i < regions.size(); ++i) {
+        RefPtr<TypeBuilder::DOM::Rect> rectObject = TypeBuilder::DOM::Rect::create()
+            .setX(regions[i].x)
+            .setY(regions[i].y)
+            .setHeight(regions[i].height)
+            .setWidth(regions[i].width);
+        RefPtr<TypeBuilder::LayerTree::ScrollRect> regionObject = TypeBuilder::LayerTree::ScrollRect::create()
+            .setRect(rectObject)
+            .setType(type);
+        scrollRects.addItem(regionObject);
+    }
+}
+
+static PassRefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::ScrollRect> > buildScrollRectsForLayer(GraphicsLayer* graphicsLayer)
+{
+    RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::ScrollRect> > scrollRects = TypeBuilder::Array<TypeBuilder::LayerTree::ScrollRect>::create();
+    blink::WebLayer* webLayer = graphicsLayer->platformLayer();
+    buildRegionObjects(webLayer->nonFastScrollableRegion(), *scrollRects, TypeBuilder::LayerTree::ScrollRect::Type::RepaintsOnScroll, idForLayer(graphicsLayer));
+    buildRegionObjects(webLayer->touchEventHandlerRegion(), *scrollRects, TypeBuilder::LayerTree::ScrollRect::Type::TouchEventHandler, idForLayer(graphicsLayer));
+    if (webLayer->haveWheelEventHandlers()) {
+        RefPtr<TypeBuilder::DOM::Rect> rectObject = TypeBuilder::DOM::Rect::create()

[pfeldman, 2014/02/28 07:43:43]

Then you would be able to reuse builder method here and would actually save on
the number of lines. There is nothing wrong in building WebRect from the layer
data for the sake of the call.

[malch, 2014/02/28 12:19:57]

Done.

+            .setX(webLayer->position().x)
+            .setY(webLayer->position().y)
+            .setHeight(webLayer->bounds().height)
+            .setWidth(webLayer->bounds().width);
+        RefPtr<TypeBuilder::LayerTree::ScrollRect> regionObject = TypeBuilder::LayerTree::ScrollRect::create()
+            .setRect(rectObject)
+            .setType(TypeBuilder::LayerTree::ScrollRect::Type::WheelEventHandler);
+        scrollRects->addItem(regionObject);
+    }
+    return scrollRects->length() ? scrollRects : nullptr;
+}
+
 static PassRefPtr<TypeBuilder::LayerTree::Layer> buildObjectForLayer(GraphicsLayer* graphicsLayer, int nodeId)
 {
     blink::WebLayer* webLayer = graphicsLayer->platformLayer();
     RefPtr<TypeBuilder::LayerTree::Layer> layerObject = TypeBuilder::LayerTree::Layer::create()
         .setLayerId(idForLayer(graphicsLayer))
         .setOffsetX(webLayer->position().x)
         .setOffsetY(webLayer->position().y)
         .setWidth(webLayer->bounds().width)
         .setHeight(webLayer->bounds().height)
         .setPaintCount(graphicsLayer->paintCount());
@@ skipping 14 matching lines @@
         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());
         layerObject->setAnchorY(anchor.y());
         layerObject->setAnchorZ(anchor.z());
     }
+    RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::ScrollRect> > scrollRects =
+        buildScrollRectsForLayer(graphicsLayer);
+    if (scrollRects)
+        layerObject->setScrollRects(buildScrollRectsForLayer(graphicsLayer));

[pfeldman, 2014/02/28 07:43:43]

Why building twice, use scrollRects instead?

Do you need a check at all? I thought we supported nullable arrays.

[malch, 2014/02/28 12:19:57]

Done.

     return layerObject;
 }
 
 InspectorLayerTreeAgent::InspectorLayerTreeAgent(InspectorDOMAgent* domAgent, Page* page)
     : InspectorBaseAgent<InspectorLayerTreeAgent>("LayerTree")
     , m_frontend(0)
     , m_page(page)
     , m_domAgent(domAgent)
 {
 }
@@ skipping 75 matching lines @@
         buildLayerIdToNodeIdMap(child, layerIdToNodeIdMap);
     if (!root->renderer()->isRenderIFrame())
         return;
     FrameView* childFrameView = toFrameView(toRenderWidget(root->renderer())->widget());
     if (RenderView* childRenderView = childFrameView->renderView()) {
         if (RenderLayerCompositor* childCompositor = childRenderView->compositor())
             buildLayerIdToNodeIdMap(childCompositor->rootRenderLayer(), layerIdToNodeIdMap);
     }
 }
 
-void InspectorLayerTreeAgent::gatherGraphicsLayers(GraphicsLayer* root, HashMap<int, int>& layerIdToNodeIdMap, RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::Layer> >& layers)
+void InspectorLayerTreeAgent::gatherGraphicsLayers(GraphicsLayer* root, HashMap<int, int>& layerIdToNodeIdMap,
+    RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::Layer> >& layers)

[pfeldman, 2014/02/28 07:43:43]

no need for new line here.

[malch, 2014/02/28 12:19:57]

Done.

 {
     int layerId = root->platformLayer()->id();
     if (m_pageOverlayLayerIds.find(layerId) != WTF::kNotFound)
         return;
     layers->addItem(buildObjectForLayer(root, layerIdToNodeIdMap.get(layerId)));
     if (GraphicsLayer* replica = root->replicaLayer())
         gatherGraphicsLayers(replica, layerIdToNodeIdMap, layers);
     for (size_t i = 0, size = root->children().size(); i < size; ++i)
         gatherGraphicsLayers(root->children()[i], layerIdToNodeIdMap, layers);
 }
@@ skipping 137 matching lines @@
 void InspectorLayerTreeAgent::didRemovePageOverlay(const GraphicsLayer* layer)
 {
     size_t index = m_pageOverlayLayerIds.find(layer->platformLayer()->id());
     if (index == WTF::kNotFound)
         return;
     m_pageOverlayLayerIds.remove(index);
 }
 
 
 } // namespace WebCore