1/*
2 * Copyright (C) 2010 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#include "ScopedEventQueue.h"
33
34#include "Event.h"
35#include "EventDispatcher.h"
36#include "EventTarget.h"
37
38namespace WebCore {
39
40ScopedEventQueue::ScopedEventQueue()
41    : m_scopingLevel(0)
42{
43}
44
45ScopedEventQueue::~ScopedEventQueue()
46{
47    ASSERT(!m_scopingLevel);
48    ASSERT(!m_queuedEvents.size());
49}
50
51ScopedEventQueue& ScopedEventQueue::instance()
52{
53    static NeverDestroyed<ScopedEventQueue> scopedEventQueue;
54    return scopedEventQueue;
55}
56
57void ScopedEventQueue::enqueueEvent(PassRefPtr<Event> event)
58{
59    if (m_scopingLevel)
60        m_queuedEvents.append(event);
61    else
62        dispatchEvent(event);
63}
64
65void ScopedEventQueue::dispatchEvent(PassRefPtr<Event> event) const
66{
67    ASSERT(event->target());
68    // Store the target in a local variable to avoid possibly dereferencing a nullified PassRefPtr after it's passed on.
69    Node* node = event->target()->toNode();
70    EventDispatcher::dispatchEvent(node, event);
71}
72
73void ScopedEventQueue::dispatchAllEvents()
74{
75    Vector<RefPtr<Event>> queuedEvents = WTF::move(m_queuedEvents);
76    for (size_t i = 0; i < queuedEvents.size(); i++)
77        dispatchEvent(queuedEvents[i].release());
78}
79
80void ScopedEventQueue::incrementScopingLevel()
81{
82    m_scopingLevel++;
83}
84
85void ScopedEventQueue::decrementScopingLevel()
86{
87    ASSERT(m_scopingLevel);
88    m_scopingLevel--;
89    if (!m_scopingLevel)
90        dispatchAllEvents();
91}
92
93}
94