IteratorImpl.h

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/*********************************************************\
 *  File: IteratorImpl.h                                 *
 *
 *  Copyright (C) 2002-2012 The PixelLight Team (http://www.pixellight.org/)
 *
 *  This file is part of PixelLight.
 *
 *  PixelLight is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  PixelLight 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with PixelLight. If not, see <http://www.gnu.org/licenses/>.
\*********************************************************/


#ifndef __PLCORE_CONTAINER_ITERATORIMPL_H__
#define __PLCORE_CONTAINER_ITERATORIMPL_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include "PLCore/Core/RefCount.h"


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
namespace PLCore {


//[-------------------------------------------------------]
//[ Forward declarations                                  ]
//[-------------------------------------------------------]
template <class ValueType> class Iterator;
template <class ValueType> class ConstIterator;


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Abstract iterator implementation class
*/
template <class ValueType>
class IteratorImpl : protected RefCount<ValueType> {


    //[-------------------------------------------------------]
    //[ Friends                                               ]
    //[-------------------------------------------------------]
    friend class Iterator<ValueType>;
    friend class ConstIterator<ValueType>;


    //[-------------------------------------------------------]
    //[ Protected virtual IteratorImpl functions              ]
    //[-------------------------------------------------------]
    protected:
        /**
        *  @brief
        *    Destructor
        */
        virtual ~IteratorImpl<ValueType>() {};

        /**
        *  @brief
        *    Creates a clone of the implementation
        *
        *  @return
        *    The created clone of the implementation, always valid
        */
        virtual IteratorImpl<ValueType> *Clone() const = 0;

        /**
        *  @brief
        *    Checks whether the iterator can return a next element
        *
        *  @return
        *    'true' if the iterator can return a next element, else 'false'
        */
        virtual bool HasNext() const = 0;

        /**
        *  @brief
        *    Returns the next element
        *
        *  @return
        *    Reference to the next element, reference to the 'Null'-object on error
        */
        virtual ValueType &Next() = 0;

        /**
        *  @brief
        *    Checks whether the iterator can return a previous element
        *
        *  @return
        *    'true' if the iterator can return a previous element, else 'false'
        */
        virtual bool HasPrevious() const = 0;

        /**
        *  @brief
        *    Returns the previous element
        *
        *  @return
        *    Reference to the previous element, reference to the 'Null'-object on error
        */
        virtual ValueType &Previous() = 0;


};


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
} // PLCore


#endif // __PLCORE_CONTAINER_ITERATORIMPL_H__