/*
 * Copyright (C) 2011 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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``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 APPLE INC. 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, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef FrameDestructionObserver_h
#define FrameDestructionObserver_h

#include "platform/heap/Handle.h"

namespace blink {

class LocalFrame;

class FrameDestructionObserver : public WillBeGarbageCollectedMixin {
public:
    explicit FrameDestructionObserver(LocalFrame*);

#if !ENABLE(OILPAN)
    // Oilpan: there is no known need for directly observing
    // frameDestroyed() with Oilpan enabled, as its clearing is
    // handled by keeping a weak reference.
    //
    // A weak callback version of frameDestroyed() can be reintroduced
    // later, should the need arise.
    virtual void frameDestroyed();
#endif
    virtual void willDetachFrameHost();

    LocalFrame* frame() const { return m_frame; }

    virtual void trace(Visitor*);

protected:
#if !ENABLE(OILPAN)
    virtual ~FrameDestructionObserver();
#endif

    void observeFrame(LocalFrame*);

    RawPtrWillBeWeakMember<LocalFrame> m_frame;
};

}

#endif
