1 /* 2 * Copyright (C) 2008 Apple Inc. All Rights Reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #ifndef NodeWithIndex_h 27 #define NodeWithIndex_h 28 29 #include "core/dom/Node.h" 30 #include "platform/heap/Handle.h" 31 32 namespace blink { 33 34 // For use when you want to get the index for a node repeatedly and 35 // only want to walk the child list to figure out the index once. 36 class NodeWithIndex { 37 STACK_ALLOCATED(); 38 public: 39 explicit NodeWithIndex(Node& node) 40 : m_node(node) 41 , m_index(-1) 42 { 43 } 44 45 Node& node() const { return *m_node; } 46 47 int index() const 48 { 49 if (!hasIndex()) 50 m_index = node().nodeIndex(); 51 ASSERT(hasIndex()); 52 ASSERT(m_index == static_cast<int>(node().nodeIndex())); 53 return m_index; 54 } 55 56 private: 57 bool hasIndex() const { return m_index >= 0; } 58 59 RawPtrWillBeMember<Node> m_node; 60 mutable int m_index; 61 }; 62 63 } 64 65 #endif 66
