Support display: contents for elements, first-line and first-letter pseudos.

third_party/WebKit/Source/core/dom/LayoutTreeBuilderTraversal.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 17 matching lines @@
 
 #include "core/HTMLNames.h"
 #include "core/dom/PseudoElement.h"
 #include "core/dom/shadow/FlatTreeTraversal.h"
 #include "core/layout/LayoutObject.h"
 
 namespace blink {
 
 namespace LayoutTreeBuilderTraversal {
 
+inline static bool hasDisplayContentsStyle(const Node& node) {
+  return node.isElementNode() && toElement(node).displayContentsStyle();
+}
+
 static bool isLayoutObjectReparented(const LayoutObject* layoutObject) {
   if (!layoutObject->node()->isElementNode())
     return false;
   if (toElement(layoutObject->node())->isInTopLayer())
     return true;
+
+  // NB: We intentionally ignore display:contents children here, since we aim to
+  // find them in the traversal.

[rune, 2016/11/08 13:09:20]

I think you can just remove this comment. The reparenting (the term reparenting
is not defined in a spec afaik) is about reparenting _elements_ into the top
layer to the extent it's defined in the fullscreen spec. Adding a comment about
display:contents here will just be confusing, I think.

[emilio, 2016/11/08 15:43:01]

Oh, ok, I see, will do.

+
   return false;
 }
 
 void ParentDetails::didTraverseInsertionPoint(
     const InsertionPoint* insertionPoint) {
   if (!m_insertionPoint) {
     m_insertionPoint = insertionPoint;
   }
 }
 
 inline static void assertPseudoElementParent(
     const PseudoElement& pseudoElement) {
   DCHECK(pseudoElement.parentNode());
   DCHECK(pseudoElement.parentNode()->canParticipateInFlatTree());
 }
 
 ContainerNode* parent(const Node& node, ParentDetails* details) {
   // TODO(hayato): Uncomment this once we can be sure
   // LayoutTreeBuilderTraversal::parent() is used only for a node which is
   // connected.
   // DCHECK(node.isConnected());
   if (node.isPseudoElement()) {
     assertPseudoElementParent(toPseudoElement(node));
     return node.parentNode();
   }
   return FlatTreeTraversal::parent(node, details);
 }
 
+LayoutObject* parentLayoutObject(const Node& node) {
+  ContainerNode* parent = LayoutTreeBuilderTraversal::parent(node);
+
+  while (parent && hasDisplayContentsStyle(*parent)) {
+    parent = LayoutTreeBuilderTraversal::parent(*parent);
+  }
+
+  return parent ? parent->layoutObject() : nullptr;
+}
+
 Node* nextSibling(const Node& node) {
   if (node.isBeforePseudoElement()) {
     assertPseudoElementParent(toPseudoElement(node));
     if (Node* next = FlatTreeTraversal::firstChild(*node.parentNode()))
       return next;
   } else {
     if (node.isAfterPseudoElement())
       return nullptr;
     if (Node* next = FlatTreeTraversal::nextSibling(node))
       return next;
@@ skipping 126 matching lines @@
     return nextNode;
   return nextAncestorSibling(node, stayWithin);
 }
 
 Node* next(const Node& node, const Node* stayWithin) {
   if (Node* child = pseudoAwareFirstChild(node))
     return child;
   return nextSkippingChildren(node, stayWithin);
 }
 
+static LayoutObject* nextSiblingLayoutObjectInternal(Node* node,
+                                                     int32_t& limit) {
+  for (Node* sibling = node; sibling && limit-- != 0;
+       sibling = LayoutTreeBuilderTraversal::nextSibling(*sibling)) {
+    LayoutObject* layoutObject = sibling->layoutObject();
+
+#if DCHECK_IS_ON()
+    if (hasDisplayContentsStyle(*sibling))
+      DCHECK(!layoutObject);
+#endif
+
+    if (!layoutObject && hasDisplayContentsStyle(*sibling)) {
+      layoutObject = nextSiblingLayoutObjectInternal(
+          pseudoAwareFirstChild(*sibling), limit);
+      if (layoutObject)
+        return layoutObject;
+      if (!limit)
+        return nullptr;
+    }
+
+    if (layoutObject && !isLayoutObjectReparented(layoutObject))
+      return layoutObject;
+  }
+
+  return nullptr;
+}
+
 LayoutObject* nextSiblingLayoutObject(const Node& node, int32_t limit) {
   DCHECK(limit == kTraverseAllSiblings || limit >= 0) << limit;
-  for (Node* sibling = LayoutTreeBuilderTraversal::nextSibling(node);
-       sibling && limit-- != 0;
-       sibling = LayoutTreeBuilderTraversal::nextSibling(*sibling)) {
+  if (LayoutObject* foundLayoutObject = nextSiblingLayoutObjectInternal(
+          LayoutTreeBuilderTraversal::nextSibling(node), limit))
+    return foundLayoutObject;
+
+  Node* maybeDisplayContentsParent = LayoutTreeBuilderTraversal::parent(node);
+  while (limit && maybeDisplayContentsParent &&
+         hasDisplayContentsStyle(*maybeDisplayContentsParent)) {
+    Node* displayContentsSibling =
+        LayoutTreeBuilderTraversal::nextSibling(*maybeDisplayContentsParent);
+    if (LayoutObject* siblingLayoutObject =
+            nextSiblingLayoutObjectInternal(displayContentsSibling, limit))
+      return siblingLayoutObject;
+    maybeDisplayContentsParent =
+        LayoutTreeBuilderTraversal::parent(*maybeDisplayContentsParent);
+  }
+
+  return nullptr;
+}
+
+static LayoutObject* previousSiblingLayoutObjectInternal(Node* node,
+                                                         int32_t& limit) {
+  for (Node* sibling = node; sibling && limit-- != 0;
+       sibling = LayoutTreeBuilderTraversal::previousSibling(*sibling)) {
     LayoutObject* layoutObject = sibling->layoutObject();
+
+#if DCHECK_IS_ON()
+    if (hasDisplayContentsStyle(*sibling))
+      DCHECK(!layoutObject);
+#endif
+
+    if (!layoutObject && hasDisplayContentsStyle(*sibling)) {
+      layoutObject = nextSiblingLayoutObjectInternal(
+          pseudoAwareFirstChild(*sibling), limit);
+      if (layoutObject)
+        return layoutObject;
+      if (!limit)
+        return nullptr;
+    }
+
     if (layoutObject && !isLayoutObjectReparented(layoutObject))
       return layoutObject;
   }
-  return 0;
+
+  return nullptr;
 }
 
 LayoutObject* previousSiblingLayoutObject(const Node& node, int32_t limit) {
   DCHECK(limit == kTraverseAllSiblings || limit >= 0) << limit;
-  for (Node* sibling = LayoutTreeBuilderTraversal::previousSibling(node);
-       sibling && limit-- != 0;
-       sibling = LayoutTreeBuilderTraversal::previousSibling(*sibling)) {
-    LayoutObject* layoutObject = sibling->layoutObject();
-    if (layoutObject && !isLayoutObjectReparented(layoutObject))
-      return layoutObject;
+  if (LayoutObject* foundLayoutObject = previousSiblingLayoutObjectInternal(
+          LayoutTreeBuilderTraversal::previousSibling(node), limit))
+    return foundLayoutObject;
+
+  Node* maybeDisplayContentsParent = LayoutTreeBuilderTraversal::parent(node);
+  while (limit && maybeDisplayContentsParent &&
+         hasDisplayContentsStyle(*maybeDisplayContentsParent)) {
+    Node* displayContentsSibling = LayoutTreeBuilderTraversal::previousSibling(
+        *maybeDisplayContentsParent);
+    if (LayoutObject* siblingLayoutObject =
+            previousSiblingLayoutObjectInternal(displayContentsSibling, limit))
+      return siblingLayoutObject;
+    maybeDisplayContentsParent =
+        LayoutTreeBuilderTraversal::parent(*maybeDisplayContentsParent);
   }
-  return 0;
+
+  return nullptr;
 }
 
 LayoutObject* nextInTopLayer(const Element& element) {
   if (!element.isInTopLayer())
     return 0;
   const HeapVector<Member<Element>>& topLayerElements =
       element.document().topLayerElements();
   size_t position = topLayerElements.find(&element);
   DCHECK_NE(position, kNotFound);
   for (size_t i = position + 1; i < topLayerElements.size(); ++i) {
     if (LayoutObject* layoutObject = topLayerElements[i]->layoutObject())
       return layoutObject;
   }
   return 0;
 }
 
 }  // namespace LayoutTreeBuilderTraversal
 
 }  // namespace blink