Changeset 270198 in webkit

Timestamp:

Nov 27, 2020, 9:45:58 AM (5 years ago)

Author:

Simon Fraser

Message:

[LFC Display] A ContainerBox can establish an inline formatting context and have box children
​https://bugs.webkit.org/show_bug.cgi?id=218736

Reviewed by Zalan Bujtas.

If a layout box establishes an inline formatting context, then the only descendant container
boxes that we should make display boxes for while traversing non-inline descendants
are those which are out of flow.

• display/DisplayTreeBuilder.cpp:

(WebCore::Display::TreeBuilder::recursiveBuildDisplayTree const):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• display/DisplayTreeBuilder.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2020-11-27  Simon Fraser  <simon.fraser@apple.com>
+
+        [LFC Display] A ContainerBox can establish an inline formatting context and have box children
+        https://bugs.webkit.org/show_bug.cgi?id=218736
+
+        Reviewed by Zalan Bujtas.
+
+        If a layout box establishes an inline formatting context, then the only descendant container
+        boxes that we should make display boxes for while traversing non-inline descendants
+        are those which are out of flow.
+
+        * display/DisplayTreeBuilder.cpp:
+        (WebCore::Display::TreeBuilder::recursiveBuildDisplayTree const):
+
 2020-11-27  Adrian Perez de Castro  <aperez@igalia.com>
 

trunk/Source/WebCore/display/DisplayTreeBuilder.cpp

@@ -142 +142 @@
 
     auto positionForChildren = InsertionPosition { downcast<ContainerBox>(*insertionPosition.currentChild) };
-    
+
+    enum class DescendantBoxInclusion { AllBoxes, OutOfFlowOnly };
+    auto boxInclusion = DescendantBoxInclusion::AllBoxes;
+
     if (layoutContainerBox.establishesInlineFormattingContext()) {
         buildInlineDisplayTree(layoutState, offsetFromRoot, downcast<Layout::ContainerBox>(layoutContainerBox), positionForChildren);
-        return;
-    }
+        boxInclusion = DescendantBoxInclusion::OutOfFlowOnly;
+    }
+
+    auto includeBox = [](DescendantBoxInclusion boxInclusion, const Layout::Box& box) {
+        switch (boxInclusion) {
+        case DescendantBoxInclusion::AllBoxes: return true;
+        case DescendantBoxInclusion::OutOfFlowOnly: return !box.isInFlow();
+        }
+        return false;
+    };
 
     for (auto& child : Layout::childrenOfType<Layout::Box>(layoutContainerBox)) {
-        if (layoutState.hasBoxGeometry(child))
+        if (includeBox(boxInclusion, child) && layoutState.hasBoxGeometry(child))
             recursiveBuildDisplayTree(layoutState, offsetFromRoot, child, positionForChildren);
     }