Source/WebCore/dom/ScopedEventQueue.cpp

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 *
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 * in the documentation and/or other materials provided with the
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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#include "config.h"
#include "ScopedEventQueue.h"

#include "Event.h"
#include "EventTarget.h"

namespace WebCore {

ScopedEventQueue* ScopedEventQueue::s_instance = 0;

ScopedEventQueue::ScopedEventQueue()
    : m_scopingLevel(0)
{
}

ScopedEventQueue::~ScopedEventQueue()
{
    ASSERT(!m_scopingLevel);
    ASSERT(!m_queuedEvents.size());
}

void ScopedEventQueue::initialize()
{
    ASSERT(!s_instance);
    OwnPtr<ScopedEventQueue> instance = adoptPtr(new ScopedEventQueue);
    s_instance = instance.leakPtr();
}

void ScopedEventQueue::enqueueEvent(PassRefPtr<Event> event)
{
    if (m_scopingLevel)
        m_queuedEvents.append(event);
    else
        dispatchEvent(event);
}

void ScopedEventQueue::dispatchAllEvents()
{
    Vector<RefPtr<Event> > queuedEvents;
    queuedEvents.swap(m_queuedEvents);

    for (size_t i = 0; i < queuedEvents.size(); i++)
        dispatchEvent(queuedEvents[i].release());
}

void ScopedEventQueue::dispatchEvent(PassRefPtr<Event> event) const
{
    RefPtr<EventTarget> eventTarget = event->target();
    eventTarget->dispatchEvent(event);
}

ScopedEventQueue* ScopedEventQueue::instance()
{
    if (!s_instance)
        initialize();

    return s_instance;
}

void ScopedEventQueue::incrementScopingLevel()
{
    m_scopingLevel++;
}

void ScopedEventQueue::decrementScopingLevel()
{
    ASSERT(m_scopingLevel);
    m_scopingLevel--;
    if (!m_scopingLevel)
        dispatchAllEvents();
}

}