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, 2013 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 24#ifndef ChildNodeList_h 25#define ChildNodeList_h 26 27#include "CollectionIndexCache.h" 28#include "NodeList.h" 29#include <wtf/Ref.h> 30#include <wtf/RefPtr.h> 31 32namespace WebCore { 33 34class ContainerNode; 35 36class EmptyNodeList final : public NodeList { 37public: 38 static PassRef<EmptyNodeList> create(Node& owner) 39 { 40 return adoptRef(*new EmptyNodeList(owner)); 41 } 42 virtual ~EmptyNodeList(); 43 44 Node& ownerNode() { return m_owner.get(); } 45 46private: 47 explicit EmptyNodeList(Node& owner) : m_owner(owner) { } 48 49 virtual unsigned length() const override { return 0; } 50 virtual Node* item(unsigned) const override { return nullptr; } 51 virtual Node* namedItem(const AtomicString&) const override { return nullptr; } 52 virtual size_t memoryCost() const override { return 0; } 53 54 virtual bool isEmptyNodeList() const override { return true; } 55 56 Ref<Node> m_owner; 57}; 58 59class ChildNodeList final : public NodeList { 60public: 61 static PassRef<ChildNodeList> create(ContainerNode& parent) 62 { 63 return adoptRef(*new ChildNodeList(parent)); 64 } 65 66 virtual ~ChildNodeList(); 67 68 ContainerNode& ownerNode() { return m_parent.get(); } 69 70 void invalidateCache(); 71 72 // For CollectionIndexCache 73 Node* collectionBegin() const; 74 Node* collectionLast() const; 75 Node* collectionEnd() const { return nullptr; } 76 void collectionTraverseForward(Node*&, unsigned count, unsigned& traversedCount) const; 77 void collectionTraverseBackward(Node*&, unsigned count) const; 78 bool collectionCanTraverseBackward() const { return true; } 79 void willValidateIndexCache() const { } 80 81private: 82 explicit ChildNodeList(ContainerNode& parent); 83 84 virtual unsigned length() const override; 85 virtual Node* item(unsigned index) const override; 86 virtual Node* namedItem(const AtomicString&) const override; 87 virtual size_t memoryCost() const override { return m_indexCache.memoryCost(); } 88 89 virtual bool isChildNodeList() const override { return true; } 90 91 Ref<ContainerNode> m_parent; 92 mutable CollectionIndexCache<ChildNodeList, Node*> m_indexCache; 93}; 94 95} // namespace WebCore 96 97#endif // ChildNodeList_h 98