107165 2013-01-17 13:08:08 -0800 Traverse the layer tree instead of the render tree in closestScrollableNodeInDocumentIfPossible() 2013-03-01 10:39:53 -0800 1 1 1 Unclassified WebKit UI Events 528+ (Nightly build) Unspecified Unspecified RESOLVED INVALID P2 Normal --- 1 tdanderson tdanderson rjkroege simon.fraser tonikitoo oldest_to_newest 809677 0 tdanderson 2013-01-17 13:08:08 -0800 Consider Antonio's comment from https://bugs.webkit.org/show_bug.cgi?id=103952#c59: > Source/WebCore/page/EventHandler.cpp:2613 > + for (Node* scrollableNode = node; scrollableNode; scrollableNode = scrollableNode->parentNode()) { > + if (scrollableNode->isDocumentNode()) > + break; > + RenderObject* renderer = scrollableNode->renderer(); > + if (renderer && renderer->isBox() && toRenderBox(renderer)->canBeScrolledAndHasScrollableArea()) > + return scrollableNode; > + } It would be faster (sometimes measurably faster) if instead of traversing the Render tree upwards, you traversed the Layer tree, given that any scrollable renderer will have an associated RenderLayer. 809687 1 tdanderson 2013-01-17 13:15:49 -0800 I should also re-consider Antonio's comment regarding a possibly-redundant boolean member variable: > Source/WebCore/page/EventHandler.cpp:2633 > + m_lastHitTestResultOverWidget = result.isOverWidget(); I do not think you need this m_lastHitTestResultOverWidget boolean. The Renderer can tell you this as well no? RenderObject::isWidget() 845296 2 tdanderson 2013-03-01 10:39:53 -0800 The function closestScrollableNodeCandidate() in EventHandler.cpp is being removed in https://bugs.webkit.org/show_bug.cgi?id=109769 since we're no longer going to be using it, so this issue is no longer valid.