/*
 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
 *           (C) 2000 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2003, 2005, 2008 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef DataRef_h
#define DataRef_h

#include <wtf/RefPtr.h>

namespace khtml
{

template <class DATA>
class DataRef
{
public:
    DataRef()
    {
        data = 0;
    }

    DataRef(const DataRef<DATA> &d)
    {
        data = d.data;
        data->ref();
    }

    ~DataRef()
    {
        if (data) {
            data->deref();
        }
    }

    const DATA *operator->() const
    {
        return data;
    }

    const DATA *get() const
    {
        return data;
    }

    DATA *access()
    {
        if (!data->hasOneRef()) {
            data->deref();
            data = new DATA(*data);
            data->ref();
        }
        return data;
    }

    void init()
    {
        data = new DATA;
        data->ref();
    }

    DataRef<DATA> &operator=(const DataRef<DATA> &d)
    {
        if (data == d.data) {
            return *this;
        }
        if (data) {
            data->deref();
        }
        data = d.data;

        data->ref();

        return *this;
    }

    bool operator == (const DataRef<DATA> &o) const
    {
        return (*data == *(o.data));
    }

    bool operator != (const DataRef<DATA> &o) const
    {
        return (*data != *(o.data));
    }

private:
    DATA *data;
};

} // namespace khtml

#endif // DataRef_h
