Changeset 275126 in webkit

Timestamp:

Mar 26, 2021, 6:37:26 PM (5 years ago)

Author:

Alan Bujtas

Message:

[RenderTreeBuilder] No need to update the counters when the renderer is moved internally
​https://bugs.webkit.org/show_bug.cgi?id=223801
<rdar://75835208>

Reviewed by Ryosuke Niwa.

When the renderer re-parenting is initiated by an "internal move" (e.g. anonymous block parent is not needed anymore so all the descendants
are moved "one level" up), we don't need to re-compute the counters. Their state should not be any different after this re-parenting.

• rendering/updating/RenderTreeBuilder.cpp:

(WebCore::RenderTreeBuilder::attachToRenderElementInternal):
(WebCore::RenderTreeBuilder::move):

• rendering/updating/RenderTreeBuilder.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/updating/RenderTreeBuilder.cpp (modified) (3 diffs)
• rendering/updating/RenderTreeBuilder.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-03-26  Zalan Bujtas  <zalan@apple.com>
+
+        [RenderTreeBuilder] No need to update the counters when the renderer is moved internally
+        https://bugs.webkit.org/show_bug.cgi?id=223801
+        <rdar://75835208>
+
+        Reviewed by Ryosuke Niwa.
+
+        When the renderer re-parenting is initiated by an "internal move" (e.g. anonymous block parent is not needed anymore so all the descendants
+        are moved "one level" up), we don't need to re-compute the counters. Their state should not be any different after this re-parenting.
+
+        * rendering/updating/RenderTreeBuilder.cpp:
+        (WebCore::RenderTreeBuilder::attachToRenderElementInternal):
+        (WebCore::RenderTreeBuilder::move):
+        * rendering/updating/RenderTreeBuilder.h:
+
 2021-03-26  Chris Fleizach  <cfleizach@apple.com>
 

trunk/Source/WebCore/rendering/updating/RenderTreeBuilder.cpp

@@ -428 +428 @@
 }
 
-void RenderTreeBuilder::attachToRenderElementInternal(RenderElement& parent, RenderPtr<RenderObject> child, RenderObject* beforeChild)
+void RenderTreeBuilder::attachToRenderElementInternal(RenderElement& parent, RenderPtr<RenderObject> child, RenderObject* beforeChild, ReinsertAfterMove reinsertAfterMove)
 {
     RELEASE_ASSERT_WITH_MESSAGE(!parent.view().frameView().layoutContext().layoutState(), "Layout must not mutate render tree");
@@ -452 +452 @@
             multiColumnBuilder().multiColumnDescendantInserted(downcast<RenderMultiColumnFlow>(*fragmentedFlow), *newChild);
 
-        if (is<RenderElement>(*newChild))
+        // FIXME: needsStateReset could probably be used for multicolumn as well.
+        auto needsStateReset = reinsertAfterMove == ReinsertAfterMove::No;
+        if (needsStateReset && is<RenderElement>(*newChild))
             RenderCounter::rendererSubtreeAttached(downcast<RenderElement>(*newChild));
     }
@@ -483 +485 @@
     } else {
         auto childToMove = detachFromRenderElement(from, child);
-        attachToRenderElementInternal(to, WTFMove(childToMove), beforeChild);
+        attachToRenderElementInternal(to, WTFMove(childToMove), beforeChild, ReinsertAfterMove::Yes);
     }
 }

trunk/Source/WebCore/rendering/updating/RenderTreeBuilder.h

@@ -71 +71 @@
     void attachToRenderGrid(RenderGrid& parent, RenderPtr<RenderObject> child, RenderObject* beforeChild = nullptr);
     void attachToRenderElement(RenderElement& parent, RenderPtr<RenderObject> child, RenderObject* beforeChild = nullptr);
-    void attachToRenderElementInternal(RenderElement& parent, RenderPtr<RenderObject> child, RenderObject* beforeChild = nullptr);
+    enum class ReinsertAfterMove { No, Yes };
+    void attachToRenderElementInternal(RenderElement& parent, RenderPtr<RenderObject> child, RenderObject* beforeChild = nullptr, ReinsertAfterMove = ReinsertAfterMove::No);
 
     enum class WillBeDestroyed { No, Yes };