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#include "config.h"
32
33#include "ChildListMutationScope.h"
34
35#include "DocumentFragment.h"
36#include "MutationObserverInterestGroup.h"
37#include "MutationRecord.h"
38#include "StaticNodeList.h"
39#include <wtf/StdLibExtras.h>
40
41namespace WebCore {
42
43typedef HashMap<ContainerNode*, ChildListMutationAccumulator*> AccumulatorMap;
44static AccumulatorMap& accumulatorMap()
45{
46    DEPRECATED_DEFINE_STATIC_LOCAL(AccumulatorMap, map, ());
47    return map;
48}
49
50ChildListMutationAccumulator::ChildListMutationAccumulator(ContainerNode& target, std::unique_ptr<MutationObserverInterestGroup> observers)
51    : m_target(target)
52    , m_lastAdded(nullptr)
53    , m_observers(WTF::move(observers))
54{
55}
56
57ChildListMutationAccumulator::~ChildListMutationAccumulator()
58{
59    if (!isEmpty())
60        enqueueMutationRecord();
61    accumulatorMap().remove(&m_target.get());
62}
63
64PassRefPtr<ChildListMutationAccumulator> ChildListMutationAccumulator::getOrCreate(ContainerNode& target)
65{
66    AccumulatorMap::AddResult result = accumulatorMap().add(&target, nullptr);
67    RefPtr<ChildListMutationAccumulator> accumulator;
68    if (!result.isNewEntry)
69        accumulator = result.iterator->value;
70    else {
71        accumulator = adoptRef(new ChildListMutationAccumulator(target, MutationObserverInterestGroup::createForChildListMutation(target)));
72        result.iterator->value = accumulator.get();
73    }
74    return accumulator.release();
75}
76
77inline bool ChildListMutationAccumulator::isAddedNodeInOrder(Node& child)
78{
79    return isEmpty() || (m_lastAdded == child.previousSibling() && m_nextSibling == child.nextSibling());
80}
81
82void ChildListMutationAccumulator::childAdded(Node& childRef)
83{
84    ASSERT(hasObservers());
85
86    Ref<Node> child(childRef);
87
88    if (!isAddedNodeInOrder(child.get()))
89        enqueueMutationRecord();
90
91    if (isEmpty()) {
92        m_previousSibling = child->previousSibling();
93        m_nextSibling = child->nextSibling();
94    }
95
96    m_lastAdded = &child.get();
97    m_addedNodes.append(child.get());
98}
99
100inline bool ChildListMutationAccumulator::isRemovedNodeInOrder(Node& child)
101{
102    return isEmpty() || m_nextSibling == &child;
103}
104
105void ChildListMutationAccumulator::willRemoveChild(Node& childRef)
106{
107    ASSERT(hasObservers());
108
109    Ref<Node> child(childRef);
110
111    if (!m_addedNodes.isEmpty() || !isRemovedNodeInOrder(child.get()))
112        enqueueMutationRecord();
113
114    if (isEmpty()) {
115        m_previousSibling = child->previousSibling();
116        m_nextSibling = child->nextSibling();
117        m_lastAdded = child->previousSibling();
118    } else
119        m_nextSibling = child->nextSibling();
120
121    m_removedNodes.append(child.get());
122}
123
124void ChildListMutationAccumulator::enqueueMutationRecord()
125{
126    ASSERT(hasObservers());
127    ASSERT(!isEmpty());
128
129    RefPtr<NodeList> addedNodes = StaticNodeList::adopt(m_addedNodes);
130    RefPtr<NodeList> removedNodes = StaticNodeList::adopt(m_removedNodes);
131    RefPtr<MutationRecord> record = MutationRecord::createChildList(m_target.get(), addedNodes.release(), removedNodes.release(), m_previousSibling.release(), m_nextSibling.release());
132    m_observers->enqueueMutationRecord(record.release());
133    m_lastAdded = 0;
134    ASSERT(isEmpty());
135}
136
137bool ChildListMutationAccumulator::isEmpty()
138{
139    bool result = m_removedNodes.isEmpty() && m_addedNodes.isEmpty();
140#ifndef NDEBUG
141    if (result) {
142        ASSERT(!m_previousSibling);
143        ASSERT(!m_nextSibling);
144        ASSERT(!m_lastAdded);
145    }
146#endif
147    return result;
148}
149
150} // namespace WebCore
151