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

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2004, 2007, 2008 Apple Inc. All rights reserved.
 * Copyright (C) 2014 Samsung Electronics. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "core/dom/ChildNodeList.h"

#include "core/dom/Element.h"
#include "core/dom/NodeRareData.h"

namespace blink {

ChildNodeList::ChildNodeList(ContainerNode& parent) : m_parent(parent) {}

Node* ChildNodeList::virtualOwnerNode() const {
  return &ownerNode();
}

ChildNodeList::~ChildNodeList() {}

Node* ChildNodeList::traverseForwardToOffset(unsigned offset,
                                             Node& currentNode,
                                             unsigned& currentOffset) const {
  DCHECK_LT(currentOffset, offset);
  DCHECK_EQ(ownerNode().childNodes(), this);
  DCHECK_EQ(&ownerNode(), currentNode.parentNode());
  for (Node* next = currentNode.nextSibling(); next;
       next = next->nextSibling()) {
    if (++currentOffset == offset)
      return next;
  }
  return 0;
}

Node* ChildNodeList::traverseBackwardToOffset(unsigned offset,
                                              Node& currentNode,
                                              unsigned& currentOffset) const {
  DCHECK_GT(currentOffset, offset);
  DCHECK_EQ(ownerNode().childNodes(), this);
  DCHECK_EQ(&ownerNode(), currentNode.parentNode());
  for (Node* previous = currentNode.previousSibling(); previous;
       previous = previous->previousSibling()) {
    if (--currentOffset == offset)
      return previous;
  }
  return 0;
}

DEFINE_TRACE(ChildNodeList) {
  visitor->trace(m_parent);
  visitor->trace(m_collectionIndexCache);
  NodeList::trace(visitor);
}

}  // namespace blink