[iOS WK1] Single touch div scrolling in Mobile Safari doesn't work in framesets (breaks Word previews)
Created attachment 235188 [details] Patch
<rdar://problem/11830219>
Comment on attachment 235188 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=235188&action=review r=me, not sure if you need to switch to a post-order traversal > Source/WebCore/rendering/RenderLayerCompositor.cpp:474 > + notifySubframesAfterLayerFlush(); > + didFlushLayers(); It seems strange to flush the top frame separately. Also, I think the function should be named for what it does rather than in what circumstance it’s called in. Maybe flushDescendantLayers, except that argues against putting it in there. > Source/WebCore/rendering/RenderLayerCompositor.cpp:500 > + for (Frame* currFrame = frame.tree().firstChild(); currFrame; currFrame = currFrame->tree().traverseNext(&frame)) { I suggest naming this variable subframe or descendant rather than currFrame. Since we want to flush subframes before their parent, this traversal is not the one we want. This is a pre-order traversal, where each frame is visited before its children. I think what we want is a post-order traversal, where children are visited before their parents. Unfortunately, we don’t have a post-order traversal function in FrameTree. It’s not hard to write one. The nextPostOrder function in NodeTraversal.cpp is not a bad model: static Frame* firstDescendantFramePostOrder(Frame& frame) { Frame* descendant = &frame; while (Frame* firstChild = descendant->tree()->firstChild()) descendant = firstChild; return descendant; } static Frame* nextFramePostOrder(Frame* frame) { Frame* next = frame->tree()->nextSibling(); if (!next) return frame->tree()->parent(); return firstDescendantFramePostOrder(*next); } And the loop is a little different: for (Frame* subframe = firstDescendantFramePostOrder(frame); subframe != &frame; subframe = nextFramePostOrder(subframe)) { ... }
The order in which we notify subframes doesn't really matter in this code, and I'd rather not add an O(N^2) post-order frame traversal.
https://trac.webkit.org/r171306