Map.h

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/*********************************************************\
 *  File: Map.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_MAP_H__
#define __PLCORE_CONTAINER_MAP_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include "PLCore/Container/Iterable.h"


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


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Abstract map (associative array) base template class
*
*  @verbatim
*    Usage example:
*    HashMap<String, MyClass*> mapHashMap;  // Hash table which manages MyClass pointers
*    MyClass *pT1=new MyClass(), *pT2=new MyClass(), *pT3=new MyClass(), *pT;  // Test instances
*    mapHashMap.Add("Lenny", pT1);  // Give pointer to T1 the name 'Lenny'
*    mapHashMap.Add("Barny", pT2);  // Give pointer to T2 the name 'Barny'
*    mapHashMap.Set("Homer", pT3);  // Give pointer to T3 the name 'Homer' by using the set function
*    pT = mapHashMap.Get("Barny");   // Give us the pointer to 'Barny'
*    pT = mapHashMap.Get("Homer");   // Give us the pointer to 'Homer'
*    pT = mapHashMap.Get("Lenny");   // Give us the pointer to 'Lenny'
*  @endverbatim
*
*  @note
*    - The standard container iterator iterates over all values (NOT the keys!) within the map, use
*      the special key iterator for iterating over all keys
*    - Within a map, you can't expect that the iterator returns the elements always in exact the same order
*    - Usually map iterators are not that performance by concept, so, try to avoid to use map iterators
*/
template <class KeyType, class ValueType>
class Map : public Iterable<ValueType> {


    //[-------------------------------------------------------]
    //[ Public static variables                               ]
    //[-------------------------------------------------------]
    public:
        static KeyType NullKey; /**< 'Null' key object, do NEVER EVER manipulate this object! */


    //[-------------------------------------------------------]
    //[ Public virtual Map functions                          ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Clears the map
        */
        virtual void Clear() = 0;

        /**
        *  @brief
        *    Checks whether the map is complete empty
        *
        *  @return
        *    'true' if the map is empty, else 'false'
        */
        virtual bool IsEmpty() const = 0;

        /**
        *  @brief
        *    Returns the number of elements/entries
        *
        *  @return
        *    Number of container elements/entries
        */
        virtual uint32 GetNumOfElements() const = 0;

        /**
        *  @brief
        *    Adds/puts a new element to the map
        *
        *  @param[in] Key
        *    The key of the new element
        *  @param[in] Value
        *    The value of the new element
        *
        *  @return
        *    'true' if all went fine, else 'false'
        *
        *  @note
        *    - You have to check by yourself whether there's already such a key within the map
        *
        *  @see
        *    - Set()
        */
        virtual bool Add(const KeyType &Key, const ValueType &Value) = 0;

        /**
        *  @brief
        *    Replaces the value of a map element
        *
        *  @param[in] Key
        *    The key of the element
        *  @param[in] NewValue
        *    The new value of the element
        *
        *  @return
        *    'true' if all went fine, else 'false' (key not found?)
        *
        *  @see
        *    - Set()
        */
        virtual bool Replace(const KeyType &Key, const ValueType &NewValue) = 0;

        /**
        *  @brief
        *    Sets (adds or replaces) the value of a map element
        *
        *  @param[in] Key
        *    The key of the element
        *  @param[in] Value
        *    The set value of the element
        *
        *  @return
        *    'false' if a new element was added, 'true' if the value was replaced
        *
        *  @remarks
        *    This function is a combination of the add and replace function and 'just' assigns
        *    a value to a given key without taking care of whether or not there's already an
        *    element with the given key inside the map.
        *
        *  @see
        *    - Add()
        *    - Replace()
        */
        virtual bool Set(const KeyType &Key, const ValueType &Value) = 0;

        /**
        *  @brief
        *    Removes an element from the map
        *
        *  @param[in] Key
        *    Key of the element which should be removed
        *
        *  @return
        *    'true' if all went fine, else 'false'
        */
        virtual bool Remove(const KeyType &Key) = 0;

        /**
        *  @brief
        *    Removes all elements with a certain value from the map
        *
        *  @param[in] Value
        *    Value to look for
        *
        *  @return
        *    Number of removed elements
        *
        *  @note
        *    - For performance reasons, try to use the Remove(<Key>) function
        *      whenever possible!
        */
        virtual uint32 RemoveValue(const ValueType &Value) = 0;

        /**
        *  @brief
        *    Returns the value of a given key
        *
        *  @param[in] Key
        *    Key to use
        *
        *  @return
        *    Reference of the value of the given key, reference to the 'Null'-object on error
        */
        virtual const ValueType &Get(const KeyType &Key) const = 0;

        /**
        *  @brief
        *    Returns the value of a given key
        *
        *  @param[in] Key
        *    Key to use
        *
        *  @return
        *    Reference of the value of the given key, reference to the 'Null'-object on error
        */
        virtual ValueType &Get(const KeyType &Key) = 0;

        /**
        *  @brief
        *    Returns a key iterator operating on the derived data structure
        *
        *  @param[in] nIndex
        *    Start index, if >= 'total number of elements' the index is set to the last valid index
        *
        *  @return
        *    Key iterator operating on the derived
        */
        virtual Iterator<KeyType> GetKeyIterator(uint32 nIndex = 0) const = 0;

        /**
        *  @brief
        *    Returns a constant key iterator operating on the derived data structure
        *
        *  @param[in] nIndex
        *    Start index, if >= 'total number of elements' the index is set to the last valid index
        *
        *  @return
        *    Constant key iterator operating on the derived
        */
        virtual ConstIterator<KeyType> GetConstKeyIterator(uint32 nIndex = 0) const = 0;

        /**
        *  @brief
        *    Returns a key iterator operating on the derived data structure and starting at the end
        *
        *  @return
        *    Key iterator operating on the derived,
        *
        *  @remarks
        *    Use this function to get a key iterator if you want to iterate in reversed order starting
        *    at the end last element.
        */
        virtual Iterator<KeyType> GetEndKeyIterator() const = 0;

        /**
        *  @brief
        *    Returns a constant key iterator operating on the derived data structure and starting at the end
        *
        *  @return
        *    Constant key iterator operating on the derived,
        *
        *  @remarks
        *    Use this function to get a constant key iterator if you want to iterate in reversed order
        *    starting at the end last element.
        */
        virtual ConstIterator<KeyType> GetConstEndKeyIterator() const = 0;


    //[-------------------------------------------------------]
    //[ Private virtual Map functions                         ]
    //[-------------------------------------------------------]
    private:
        /**
        *  @brief
        *    Makes this map to a copy of another map
        *
        *  @param[in] cMap
        *    Map to copy from
        *
        *  @return
        *    Reference to this instance
        */
        virtual Map<KeyType, ValueType> &operator =(const Map<KeyType, ValueType> &cMap) = 0;


};


//[-------------------------------------------------------]
//[ Public static variables                               ]
//[-------------------------------------------------------]
template <class KeyType, class ValueType> KeyType Map<KeyType, ValueType>::NullKey;


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


#endif // __PLCORE_CONTAINER_MAP_H__