1/*
2 * Copyright (C) 2011 Google 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 are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#pragma once
32
33#include "ContainerNode.h"
34#include "Document.h"
35#include "MutationObserver.h"
36#include <memory>
37#include <wtf/Noncopyable.h>
38#include <wtf/RefCounted.h>
39
40namespace WebCore {
41
42class MutationObserverInterestGroup;
43
44// ChildListMutationAccumulator is not meant to be used directly; ChildListMutationScope is the public interface.
45class ChildListMutationAccumulator : public RefCounted<ChildListMutationAccumulator> {
46public:
47 static Ref<ChildListMutationAccumulator> getOrCreate(ContainerNode&);
48 ~ChildListMutationAccumulator();
49
50 void childAdded(Node&);
51 void willRemoveChild(Node&);
52
53 bool hasObservers() const { return !!m_observers; }
54
55private:
56 ChildListMutationAccumulator(ContainerNode&, std::unique_ptr<MutationObserverInterestGroup>);
57
58 void enqueueMutationRecord();
59 bool isEmpty();
60 bool isAddedNodeInOrder(Node&);
61 bool isRemovedNodeInOrder(Node&);
62
63 Ref<ContainerNode> m_target;
64
65 Vector<Ref<Node>> m_removedNodes;
66 Vector<Ref<Node>> m_addedNodes;
67 RefPtr<Node> m_previousSibling;
68 RefPtr<Node> m_nextSibling;
69 Node* m_lastAdded;
70
71 std::unique_ptr<MutationObserverInterestGroup> m_observers;
72};
73
74class ChildListMutationScope {
75 WTF_MAKE_NONCOPYABLE(ChildListMutationScope);
76public:
77 explicit ChildListMutationScope(ContainerNode& target)
78 {
79 if (target.document().hasMutationObserversOfType(MutationObserver::ChildList))
80 m_accumulator = ChildListMutationAccumulator::getOrCreate(target);
81 }
82
83 bool canObserve() const { return m_accumulator; }
84
85 void childAdded(Node& child)
86 {
87 if (m_accumulator && m_accumulator->hasObservers())
88 m_accumulator->childAdded(child);
89 }
90
91 void willRemoveChild(Node& child)
92 {
93 if (m_accumulator && m_accumulator->hasObservers())
94 m_accumulator->willRemoveChild(child);
95 }
96
97private:
98 RefPtr<ChildListMutationAccumulator> m_accumulator;
99};
100
101} // namespace WebCore
102