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
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 */
26
27#include "config.h"
28#include "EventQueue.h"
29
30#include "DOMWindow.h"
31#include "Document.h"
32#include "Event.h"
33#include "EventNames.h"
34#include "RuntimeApplicationChecks.h"
35#include "ScriptExecutionContext.h"
36#include "SuspendableTimer.h"
37
38namespace WebCore {
39
40static inline bool shouldDispatchScrollEventSynchronously(Document* document)
41{
42    ASSERT_ARG(document, document);
43    return applicationIsSafari() && (document->url().protocolIs("feed") || document->url().protocolIs("feeds"));
44}
45
46class EventQueueTimer : public SuspendableTimer {
47    WTF_MAKE_NONCOPYABLE(EventQueueTimer);
48public:
49    EventQueueTimer(EventQueue* eventQueue, ScriptExecutionContext* context)
50        : SuspendableTimer(context)
51        , m_eventQueue(eventQueue) { }
52
53private:
54    virtual void fired() { m_eventQueue->pendingEventTimerFired(); }
55    EventQueue* m_eventQueue;
56};
57
58PassRefPtr<EventQueue> EventQueue::create(ScriptExecutionContext* context)
59{
60    return adoptRef(new EventQueue(context));
61}
62
63EventQueue::EventQueue(ScriptExecutionContext* context)
64    : m_pendingEventTimer(adoptPtr(new EventQueueTimer(this, context)))
65{
66}
67
68EventQueue::~EventQueue()
69{
70}
71
72void EventQueue::enqueueEvent(PassRefPtr<Event> event)
73{
74    ASSERT(event->target());
75    bool wasAdded = m_queuedEvents.add(event).second;
76    ASSERT_UNUSED(wasAdded, wasAdded); // It should not have already been in the list.
77
78    if (!m_pendingEventTimer->isActive())
79        m_pendingEventTimer->startOneShot(0);
80}
81
82void EventQueue::enqueueOrDispatchScrollEvent(PassRefPtr<Node> target, ScrollEventTargetType targetType)
83{
84    // Per the W3C CSSOM View Module, scroll events fired at the document should bubble, others should not.
85    bool canBubble = targetType == ScrollEventDocumentTarget;
86    RefPtr<Event> scrollEvent = Event::create(eventNames().scrollEvent, canBubble, false /* non cancelleable */);
87
88    if (shouldDispatchScrollEventSynchronously(target->document())) {
89        target->dispatchEvent(scrollEvent.release());
90        return;
91    }
92
93    if (!m_nodesWithQueuedScrollEvents.add(target.get()).second)
94        return;
95
96    scrollEvent->setTarget(target);
97    enqueueEvent(scrollEvent.release());
98}
99
100bool EventQueue::cancelEvent(Event* event)
101{
102    bool found = m_queuedEvents.contains(event);
103    m_queuedEvents.remove(event);
104    if (m_queuedEvents.isEmpty())
105        m_pendingEventTimer->stop();
106    return found;
107}
108
109void EventQueue::cancelQueuedEvents()
110{
111    m_pendingEventTimer->stop();
112    m_queuedEvents.clear();
113}
114
115void EventQueue::pendingEventTimerFired()
116{
117    ASSERT(!m_pendingEventTimer->isActive());
118    ASSERT(!m_queuedEvents.isEmpty());
119
120    m_nodesWithQueuedScrollEvents.clear();
121
122    // Insert a marker for where we should stop.
123    ASSERT(!m_queuedEvents.contains(0));
124    bool wasAdded = m_queuedEvents.add(0).second;
125    ASSERT_UNUSED(wasAdded, wasAdded); // It should not have already been in the list.
126
127    RefPtr<EventQueue> protector(this);
128
129    while (!m_queuedEvents.isEmpty()) {
130        ListHashSet<RefPtr<Event> >::iterator iter = m_queuedEvents.begin();
131        RefPtr<Event> event = *iter;
132        m_queuedEvents.remove(iter);
133        if (!event)
134            break;
135        dispatchEvent(event.get());
136    }
137}
138
139void EventQueue::dispatchEvent(PassRefPtr<Event> event)
140{
141    EventTarget* eventTarget = event->target();
142    if (eventTarget->toDOMWindow())
143        eventTarget->toDOMWindow()->dispatchEvent(event, 0);
144    else
145        eventTarget->dispatchEvent(event);
146}
147
148}
149