/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ScopedEventQueue_h
#define ScopedEventQueue_h

#include <wtf/Noncopyable.h>
#include <wtf/PassOwnPtr.h>
#include <wtf/PassRefPtr.h>
#include <wtf/Vector.h>

namespace WebCore {

class Event;

class ScopedEventQueue {
    WTF_MAKE_NONCOPYABLE(ScopedEventQueue);

public:
    ~ScopedEventQueue();

    void enqueueEvent(PassRefPtr<Event>);
    void dispatchAllEvents();
    static ScopedEventQueue* instance();

    void incrementScopingLevel();
    void decrementScopingLevel();

private:
    ScopedEventQueue();
    static void initialize();
    void dispatchEvent(PassRefPtr<Event>) const;

    Vector<RefPtr<Event> > m_queuedEvents;
    unsigned m_scopingLevel;

    static ScopedEventQueue* s_instance;
};

class EventQueueScope {
    WTF_MAKE_NONCOPYABLE(EventQueueScope);

public:
    EventQueueScope() { ScopedEventQueue::instance()->incrementScopingLevel(); }
    ~EventQueueScope() { ScopedEventQueue::instance()->decrementScopingLevel(); }
};

}

#endif // ScopedEventQueue_h