/*

 * 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,

 * 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 WebPrivatePtr_h

#define WebPrivatePtr_h

#if WEBKIT_IMPLEMENTATION

#include <wtf/PassRefPtr.h>

#endif

namespace WebKit {

// This class is an implementation detail of the WebKit API.  It exists

// to help simplify the implementation of WebKit interfaces that merely

// wrap a reference counted WebCore class.

template <typename T>

class WebPrivatePtr {

public:

    WebPrivatePtr() : m_ptr(0) { }

    ~WebPrivatePtr() { WEBKIT_ASSERT(!m_ptr); }

    bool isNull() const { return !m_ptr; }

#if WEBKIT_IMPLEMENTATION

    WebPrivatePtr(const PassRefPtr<T>& prp)

        : m_ptr(prp.releaseRef())

    {

    }

    void reset()

    {

        assign(0);

    }

    WebPrivatePtr<T>& operator=(const WebPrivatePtr<T>& other)

    {

        T* p = other.m_ptr;

        if (p)

            p->ref();

        assign(p);

        return *this;

    }

    WebPrivatePtr<T>& operator=(const PassRefPtr<T>& prp)

    {

        assign(prp.releaseRef());

        return *this;

    }

    T* get() const

    {

        return m_ptr;

    }

    T* operator->() const

    {

        ASSERT(m_ptr);

        return m_ptr;

    }

#endif

private:

#if WEBKIT_IMPLEMENTATION

    void assign(T* p)

    {

        // p is already ref'd for us by the caller

        if (m_ptr)

            m_ptr->deref();

        m_ptr = p;

    }

#endif

    T* m_ptr;

};

} // namespace WebKit

#endif