/*

 * Copyright (C) 2010 Apple 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 APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 GenericCallback_h

#define GenericCallback_h

#include "WKAPICast.h"

#include <wtf/PassRefPtr.h>

#include <wtf/RefCounted.h>

namespace WebKit {

template<typename APIReturnValueType, typename InternalReturnValueType = typename APITypeInfo<APIReturnValueType>::ImplType>

class GenericCallback : public RefCounted<GenericCallback<APIReturnValueType, InternalReturnValueType> > {

public:

    typedef void (*CallbackFunction)(APIReturnValueType, void*);

    typedef void (*CallbackDisposeFunction)(void*);

    static PassRefPtr<GenericCallback> create(void* context, CallbackFunction callback, CallbackDisposeFunction disposeCallback)

    {

        return adoptRef(new GenericCallback(context, callback, disposeCallback));

    }

    ~GenericCallback()

    {

        ASSERT(!m_callback);

    }

    void performCallbackWithReturnValue(InternalReturnValueType returnValue)

    {

        ASSERT(m_callback);

        m_callback(toRef(returnValue), m_context);

        m_callback = 0;

        m_disposeCallback = 0;

    }

    void invalidate()

    {

        ASSERT(m_callback);

        m_disposeCallback(m_context);

        m_callback = 0;

        m_disposeCallback = 0;

    }

    uint64_t callbackID() const { return m_callbackID; }

private:

    static uint64_t generateCallbackID()

    {

        static uint64_t uniqueCallbackID = 1;

        return uniqueCallbackID++;

    }

    GenericCallback(void* context, CallbackFunction callback, CallbackDisposeFunction disposeCallback)

        : m_context(context)

        , m_callback(callback)

        , m_disposeCallback(disposeCallback)

        , m_callbackID(generateCallbackID())

    {

    }

    void* m_context;

    CallbackFunction m_callback;

    CallbackDisposeFunction m_disposeCallback;

    uint64_t m_callbackID;

};

} // namespace WebKit

#endif // GenericCallback_h