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 15 matching lines @@
 
 #include "core/dom/LayoutTreeBuilderTraversal.h"
 
 #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).hasDisplayContentsStyle();
+}
 
 static bool isLayoutObjectReparented(const LayoutObject* layoutObject) {
   if (!layoutObject->node()->isElementNode())
     return false;
-  if (toElement(layoutObject->node())->isInTopLayer())
-    return true;
-  return false;
+  return toElement(layoutObject->node())->isInTopLayer();
 }
 
-void ParentDetails::didTraverseInsertionPoint(
+void LayoutTreeBuilderTraversal::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) {
+ContainerNode* LayoutTreeBuilderTraversal::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);
 }
 
-Node* nextSibling(const Node& node) {
+ContainerNode* LayoutTreeBuilderTraversal::layoutParent(
+    const Node& node,
+    ParentDetails* details) {
+  ContainerNode* parent = LayoutTreeBuilderTraversal::parent(node, details);
+
+  while (parent && hasDisplayContentsStyle(*parent))
+    parent = LayoutTreeBuilderTraversal::parent(*parent, details);
+
+  return parent;
+}
+
+LayoutObject* LayoutTreeBuilderTraversal::parentLayoutObject(const Node& node) {
+  ContainerNode* parent = LayoutTreeBuilderTraversal::layoutParent(node);
+  return parent ? parent->layoutObject() : nullptr;
+}
+
+Node* LayoutTreeBuilderTraversal::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;
   }
 
   Node* parent = FlatTreeTraversal::parent(node);
   if (parent && parent->isElementNode())
     return toElement(parent)->pseudoElement(PseudoIdAfter);
 
   return nullptr;
 }
 
-Node* previousSibling(const Node& node) {
+Node* LayoutTreeBuilderTraversal::previousSibling(const Node& node) {
   if (node.isAfterPseudoElement()) {
     assertPseudoElementParent(toPseudoElement(node));
     if (Node* previous = FlatTreeTraversal::lastChild(*node.parentNode()))
       return previous;
   } else {
     if (node.isBeforePseudoElement())
       return nullptr;
     if (Node* previous = FlatTreeTraversal::previousSibling(node))
       return previous;
   }
 
   Node* parent = FlatTreeTraversal::parent(node);
   if (parent && parent->isElementNode())
     return toElement(parent)->pseudoElement(PseudoIdBefore);
 
   return nullptr;
 }
 
 static Node* lastChild(const Node& node) {
   return FlatTreeTraversal::lastChild(node);
 }
 
 static Node* pseudoAwarePreviousSibling(const Node& node) {
-  Node* previousNode = previousSibling(node);
-  Node* parentNode = parent(node);
+  Node* previousNode = LayoutTreeBuilderTraversal::previousSibling(node);
+  Node* parentNode = LayoutTreeBuilderTraversal::parent(node);
 
   if (parentNode && parentNode->isElementNode() && !previousNode) {
     if (node.isAfterPseudoElement()) {
       if (Node* child = lastChild(*parentNode))
         return child;
     }
     if (!node.isBeforePseudoElement())
       return toElement(parentNode)->pseudoElement(PseudoIdBefore);
   }
   return previousNode;
 }
 
 static Node* pseudoAwareLastChild(const Node& node) {
   if (node.isElementNode()) {
     const Element& currentElement = toElement(node);
     Node* last = currentElement.pseudoElement(PseudoIdAfter);
     if (last)
       return last;
 
     last = lastChild(currentElement);
     if (!last)
       last = currentElement.pseudoElement(PseudoIdBefore);
     return last;
   }
 
   return lastChild(node);
 }
 
-Node* previous(const Node& node, const Node* stayWithin) {
+Node* LayoutTreeBuilderTraversal::previous(const Node& node,
+                                           const Node* stayWithin) {
   if (node == stayWithin)
     return 0;
 
   if (Node* previousNode = pseudoAwarePreviousSibling(node)) {
     while (Node* previousLastChild = pseudoAwareLastChild(*previousNode))
       previousNode = previousLastChild;
     return previousNode;
   }
   return parent(node);
 }
 
-Node* firstChild(const Node& node) {
+Node* LayoutTreeBuilderTraversal::firstChild(const Node& node) {
   return FlatTreeTraversal::firstChild(node);
 }
 
 static Node* pseudoAwareNextSibling(const Node& node) {
-  Node* parentNode = parent(node);
-  Node* nextNode = nextSibling(node);
+  Node* parentNode = LayoutTreeBuilderTraversal::parent(node);
+  Node* nextNode = LayoutTreeBuilderTraversal::nextSibling(node);
 
   if (parentNode && parentNode->isElementNode() && !nextNode) {
     if (node.isBeforePseudoElement()) {
-      if (Node* child = firstChild(*parentNode))
+      if (Node* child = LayoutTreeBuilderTraversal::firstChild(*parentNode))
         return child;
     }
     if (!node.isAfterPseudoElement())
       return toElement(parentNode)->pseudoElement(PseudoIdAfter);
   }
   return nextNode;
 }
 
 static Node* pseudoAwareFirstChild(const Node& node) {
   if (node.isElementNode()) {
     const Element& currentElement = toElement(node);
     Node* first = currentElement.pseudoElement(PseudoIdBefore);
     if (first)
       return first;
-    first = firstChild(currentElement);
+    first = LayoutTreeBuilderTraversal::firstChild(currentElement);
     if (!first)
       first = currentElement.pseudoElement(PseudoIdAfter);
     return first;
   }
 
-  return firstChild(node);
+  return LayoutTreeBuilderTraversal::firstChild(node);
 }
 
 static Node* nextAncestorSibling(const Node& node, const Node* stayWithin) {
   DCHECK(!pseudoAwareNextSibling(node));
   DCHECK_NE(node, stayWithin);
-  for (Node* parentNode = parent(node); parentNode;
-       parentNode = parent(*parentNode)) {
+  for (Node* parentNode = LayoutTreeBuilderTraversal::parent(node); parentNode;
+       parentNode = LayoutTreeBuilderTraversal::parent(*parentNode)) {
     if (parentNode == stayWithin)
       return 0;
     if (Node* nextNode = pseudoAwareNextSibling(*parentNode))
       return nextNode;
   }
   return 0;
 }
 
-Node* nextSkippingChildren(const Node& node, const Node* stayWithin) {
+Node* LayoutTreeBuilderTraversal::nextSkippingChildren(const Node& node,
+                                                       const Node* stayWithin) {
   if (node == stayWithin)
     return 0;
   if (Node* nextNode = pseudoAwareNextSibling(node))
     return nextNode;
   return nextAncestorSibling(node, stayWithin);
 }
 
-Node* next(const Node& node, const Node* stayWithin) {
+Node* LayoutTreeBuilderTraversal::next(const Node& node,
+                                       const Node* stayWithin) {
   if (Node* child = pseudoAwareFirstChild(node))
     return child;
   return nextSkippingChildren(node, stayWithin);
 }
 
-LayoutObject* nextSiblingLayoutObject(const Node& node, int32_t limit) {
-  DCHECK(limit == kTraverseAllSiblings || limit >= 0) << limit;
-  for (Node* sibling = LayoutTreeBuilderTraversal::nextSibling(node);
-       sibling && limit-- != 0;
+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 0;
+
+  return nullptr;
 }
 
-LayoutObject* previousSiblingLayoutObject(const Node& node, int32_t limit) {
+LayoutObject* LayoutTreeBuilderTraversal::nextSiblingLayoutObject(
+    const Node& node,
+    int32_t limit) {
   DCHECK(limit == kTraverseAllSiblings || limit >= 0) << limit;
-  for (Node* sibling = LayoutTreeBuilderTraversal::previousSibling(node);
-       sibling && limit-- != 0;
+  if (LayoutObject* sibling =
+          nextSiblingLayoutObjectInternal(nextSibling(node), limit))
+    return sibling;
+
+  Node* parent = LayoutTreeBuilderTraversal::parent(node);
+  while (limit && parent && hasDisplayContentsStyle(*parent)) {
+    if (LayoutObject* sibling =
+            nextSiblingLayoutObjectInternal(nextSibling(*parent), limit))
+      return sibling;
+    parent = LayoutTreeBuilderTraversal::parent(*parent);
+  }
+
+  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 = previousSiblingLayoutObjectInternal(
+          pseudoAwareLastChild(*sibling), limit);
+      if (layoutObject)
+        return layoutObject;
+      if (!limit)
+        return nullptr;
+    }
+
     if (layoutObject && !isLayoutObjectReparented(layoutObject))
       return layoutObject;
   }
-  return 0;
+
+  return nullptr;
 }
 
-LayoutObject* nextInTopLayer(const Element& element) {
+LayoutObject* LayoutTreeBuilderTraversal::previousSiblingLayoutObject(
+    const Node& node,
+    int32_t limit) {
+  DCHECK(limit == kTraverseAllSiblings || limit >= 0) << limit;
+  if (LayoutObject* sibling =
+          previousSiblingLayoutObjectInternal(previousSibling(node), limit))
+    return sibling;
+
+  Node* parent = LayoutTreeBuilderTraversal::parent(node);
+  while (limit && parent && hasDisplayContentsStyle(*parent)) {
+    if (LayoutObject* sibling = previousSiblingLayoutObjectInternal(
+            previousSibling(*parent), limit))
+      return sibling;
+    parent = LayoutTreeBuilderTraversal::parent(*parent);
+  }
+
+  return nullptr;
+}
+
+LayoutObject* LayoutTreeBuilderTraversal::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