Add a DOM.getLayoutTreeNodes devtools command

third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp

Index: third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp
diff --git a/third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp b/third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp
index 0f5b4712fe0ab5954057bacea35eee015f31bd09..a8417779659d6ac39d72ce95bd082414bf011ffc 100644
--- a/third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp
+++ b/third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp
@@ -66,7 +66,9 @@
 #include "core/inspector/InspectorHistory.h"
 #include "core/inspector/V8InspectorString.h"
 #include "core/layout/HitTestResult.h"
+#include "core/layout/LayoutInline.h"
 #include "core/layout/api/LayoutViewItem.h"
+#include "core/layout/line/InlineTextBox.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/page/FrameTree.h"
 #include "core/page/Page.h"
@@ -528,6 +530,83 @@ void InspectorDOMAgent::getDocument(ErrorString* errorString, std::unique_ptr<pr
     *root = buildObjectForNode(m_document.get(), 2, m_documentNodeToIdMap.get());
 }
 
+namespace {
+std::unique_ptr<protocol::DOM::Rect> getRectForFloatRect(const FloatRect& rect)

[pfeldman, 2016/09/16 00:59:35]

We call these build*. Also, either move those to the top of the file or drop the
namespace and use static modifiers.

[alex clarke (OOO till 29th), 2016/09/16 10:23:36]

Done.

+{
+    return protocol::DOM::Rect::create()
+        .setX(rect.x())
+        .setY(rect.y())
+        .setWidth(rect.width())
+        .setHeight(rect.height())
+        .build();
+}
+
+FloatRect getAbsoluteBoundingBox(LayoutObject* layoutObject)

[pfeldman, 2016/09/16 00:59:35]

Blink does not (yet) use get prefixes.

[alex clarke (OOO till 29th), 2016/09/16 10:23:36]

Done.

+{
+    if (layoutObject->isText()) {
+        FloatRect localRect(toLayoutText(layoutObject)->linesBoundingBox());
+        return layoutObject->localToAbsoluteQuad(localRect).boundingBox();

[pfeldman, 2016/09/16 00:59:35]

I am not sure this matches your expectations wrt coordinate system, but you'll
know better once you apply it. Make sure you checked it for the iframes,
scrolled iframes, etc.

[alex clarke (OOO till 29th), 2016/09/16 10:23:36]

Acknowledged.

+    }
+    if (layoutObject->isLayoutInline()) {
+        FloatRect localRect(toLayoutInline(layoutObject)->linesBoundingBox());
+        return layoutObject->localToAbsoluteQuad(localRect).boundingBox();
+    }
+    if (layoutObject->isBox()) {
+        FloatRect localRect(toLayoutBox(layoutObject)->borderBoxRect());
+        return layoutObject->localToAbsoluteQuad(localRect).boundingBox();
+    }
+    return layoutObject->absoluteBoundingBoxRect();
+}
+
+} // namespace
+
+void InspectorDOMAgent::getRenderTreeNodes(ErrorString* errorString, std::unique_ptr<protocol::Array<protocol::DOM::RenderTreeNode>>* renderTreeNodes)
+{
+    renderTreeNodes->reset(new protocol::Array<protocol::DOM::RenderTreeNode>);
+
+    std::vector<Node*> unvisited; // Neither WTF::Vector or HeapVector allow Node* :(
+    unvisited.push_back(m_document.get());
+
+    while (!unvisited.empty()) {
+        Node* node = unvisited.back();
+        unvisited.pop_back();
+        LayoutObject* layoutObject = node->layoutObject();
+        if (!layoutObject)

[pfeldman, 2016/09/16 00:59:35]

You still might want to go over the dom hierarchy.

[alex clarke (OOO till 29th), 2016/09/16 10:23:36]

Good point!

+            continue;
+
+        int backendNodeId = DOMNodeIds::idForNode(node);
+        DCHECK(backendNodeId);

[pfeldman, 2016/09/16 00:59:35]

It is always there

[alex clarke (OOO till 29th), 2016/09/16 10:23:36]

Done.

+        std::unique_ptr<protocol::DOM::RenderTreeNode> renderTreeNode =
+            protocol::DOM::RenderTreeNode::create()
+                .setBackendNodeId(backendNodeId)
+                .setBoundingBox(getRectForFloatRect(getAbsoluteBoundingBox(layoutObject)))
+                .build();
+
+        if (layoutObject->isText()) {
+            LayoutText* layoutText = toLayoutText(layoutObject);
+            renderTreeNode->setLayoutText(layoutText->text());
+            if (layoutText->hasTextBoxes()) {
+                std::unique_ptr<protocol::Array<protocol::DOM::InlineTextBox>> inlineTextNodes(new protocol::Array<protocol::DOM::InlineTextBox>());
+                for (const InlineTextBox* itb = layoutText->firstTextBox(); itb; itb = itb->nextTextBox()) {
+                    FloatRect localItbRect(itb->calculateBoundaries());
+                    FloatRect absoluteItbRect = layoutObject->localToAbsoluteQuad(localItbRect).boundingBox();
+                    inlineTextNodes->addItem(
+                        protocol::DOM::InlineTextBox::create()
+                            .setText(layoutText->text().substring(itb->start(), itb->len()).utf8().data())
+                            .setBoundingBox(getRectForFloatRect(absoluteItbRect))
+                            .build());
+                }
+                renderTreeNode->setInlineTextNodes(std::move(inlineTextNodes));
+            }
+        }
+
+        (*renderTreeNodes)->addItem(std::move(renderTreeNode));
+
+        for (node = innerFirstChild(node); node; node = innerNextSibling(node))

[pfeldman, 2016/09/16 00:59:35]

I don't see where you account for the shadow dom. Also, this seems to be an
array of layout objects for nodes rather than the render tree. Didn't you want
to traverse the render tree instead?

[alex clarke (OOO till 29th), 2016/09/16 10:23:36]

Hopefully I've done that now.
I'm under the impression that we don't want to traverse the render tree. 
Perhaps we should discuss this offline?

+            unvisited.push_back(node);
+    }
+}
+
 void InspectorDOMAgent::pushChildNodesToFrontend(int nodeId, int depth)
 {
     Node* node = nodeForId(nodeId);