1/** 2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org) 3 * (C) 1999 Antti Koivisto (koivisto@kde.org) 4 * (C) 2001 Dirk Mueller (mueller@kde.org) 5 * Copyright (C) 2004, 2007, 2008 Apple Inc. All rights reserved. 6 * 7 * This library is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Library General Public 9 * License as published by the Free Software Foundation; either 10 * version 2 of the License, or (at your option) any later version. 11 * 12 * This library is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Library General Public License for more details. 16 * 17 * You should have received a copy of the GNU Library General Public License 18 * along with this library; see the file COPYING.LIB. If not, write to 19 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 20 * Boston, MA 02110-1301, USA. 21 */ 22 23#include "config.h" 24#include "ChildNodeList.h" 25 26#include "Element.h" 27 28namespace WebCore { 29 30ChildNodeList::ChildNodeList(PassRefPtr<Node> rootNode, DynamicNodeList::Caches* info) 31 : DynamicNodeList(rootNode, info) 32{ 33} 34 35unsigned ChildNodeList::length() const 36{ 37 if (m_caches->isLengthCacheValid) 38 return m_caches->cachedLength; 39 40 unsigned len = 0; 41 for (Node* n = m_rootNode->firstChild(); n; n = n->nextSibling()) 42 len++; 43 44 m_caches->cachedLength = len; 45 m_caches->isLengthCacheValid = true; 46 47 return len; 48} 49 50Node* ChildNodeList::item(unsigned index) const 51{ 52 unsigned int pos = 0; 53 Node* n = m_rootNode->firstChild(); 54 55 if (m_caches->isItemCacheValid) { 56 if (index == m_caches->lastItemOffset) 57 return m_caches->lastItem; 58 59 int diff = index - m_caches->lastItemOffset; 60 unsigned dist = abs(diff); 61 if (dist < index) { 62 n = m_caches->lastItem; 63 pos = m_caches->lastItemOffset; 64 } 65 } 66 67 if (m_caches->isLengthCacheValid) { 68 if (index >= m_caches->cachedLength) 69 return 0; 70 71 int diff = index - pos; 72 unsigned dist = abs(diff); 73 if (dist > m_caches->cachedLength - 1 - index) { 74 n = m_rootNode->lastChild(); 75 pos = m_caches->cachedLength - 1; 76 } 77 } 78 79 if (pos <= index) { 80 while (n && pos < index) { 81 n = n->nextSibling(); 82 ++pos; 83 } 84 } else { 85 while (n && pos > index) { 86 n = n->previousSibling(); 87 --pos; 88 } 89 } 90 91 if (n) { 92 m_caches->lastItem = n; 93 m_caches->lastItemOffset = pos; 94 m_caches->isItemCacheValid = true; 95 return n; 96 } 97 98 return 0; 99} 100 101bool ChildNodeList::nodeMatches(Element* testNode) const 102{ 103 // Note: Due to the overrides of the length and item functions above, 104 // this function will be called only by DynamicNodeList::itemWithName, 105 // for an element that was located with getElementById. 106 return testNode->parentNode() == m_rootNode; 107} 108 109} // namespace WebCore 110