Source/core/events/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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 * notice, this list of conditions and the following disclaimer.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 *
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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#include "config.h"
#include "core/events/ScopedEventQueue.h"

#include "core/events/Event.h"
#include "core/events/EventDispatchMediator.h"
#include "core/events/EventDispatcher.h"
#include "core/events/EventTarget.h"
#include "wtf/OwnPtr.h"
#include "wtf/RefPtr.h"

namespace WebCore {

ScopedEventQueue* ScopedEventQueue::s_instance = 0;

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

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

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

void ScopedEventQueue::enqueueEventDispatchMediator(PassRefPtr<EventDispatchMediator> mediator)
{
    if (m_scopingLevel)
        m_queuedEventDispatchMediators.append(mediator);
    else
        dispatchEvent(mediator);
}

void ScopedEventQueue::dispatchAllEvents()
{
    Vector<RefPtr<EventDispatchMediator> > queuedEventDispatchMediators;
    queuedEventDispatchMediators.swap(m_queuedEventDispatchMediators);

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

void ScopedEventQueue::dispatchEvent(PassRefPtr<EventDispatchMediator> mediator) const
{
    ASSERT(mediator->event()->target());
    Node* node = mediator->event()->target()->toNode();
    EventDispatcher::dispatchEvent(node, mediator);
}

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();
}

}