source: code/branches/tutorial/src/orxonox/core/MetaObjectList.h @ 859

/*
 *   ORXONOX - the hottest 3D action shooter ever to exist
 *
 *
 *   License notice:
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation; either version 2
 *   of the License, or (at your option) any later version.
 *
 *   This program 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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 *   Author:
 *      Fabian 'x3n' Landau
 *   Co-authors:
 *      ...
 *
 */

/*!
    @file MetaObjectList.h
    @brief Definition of the MetaObjectList class.

    The MetaObjectList is a single-linked list, containing all list-elements and their
    lists wherein the object, owning the MetaObjectList, is registered.
    This allows much faster deletion of objects because no iteration is needed.
*/

#ifndef _MetaObjectList_H__
#define _MetaObjectList_H__

#include "CorePrereqs.h"

#include "ObjectList.h"
#include "Identifier.h"
#include "Debug.h"

namespace orxonox
{
    //! Base-class of MetaObjectListElement, because those is a template
    class BaseMetaObjectListElement
    {
        public:
            /** @brief Default destructor */
            virtual ~BaseMetaObjectListElement() {};

            BaseMetaObjectListElement* next_;       //!< The next Element in the list
    };

    // ###############################
    // ###  MetaObjectListElement  ###
    // ###############################
    //! The list-element of the MetaObjectList
    template <class T>
    class MetaObjectListElement : public BaseMetaObjectListElement
    {
        public:
            MetaObjectListElement(ObjectList<T>* list, ObjectListElement<T>* element);
            virtual ~MetaObjectListElement();

            ObjectListElement<T>* element_;         //!< The list element, containing the object
            ObjectList<T>* list_;                   //!< The list, containing the element
    };

    /**
        @brief Constructor: Creates the list-element with given list and element.
    */
    template <class T>
    MetaObjectListElement<T>::MetaObjectListElement(ObjectList<T>* list, ObjectListElement<T>* element)
    {
        this->element_ = element;
        this->list_ = list;
        this->next_ = 0;
    }

    /**
        @brief Destructor: Removes the ObjectListElement from the ObjectList by linking next_ and prev_ of the ObjectListElement.
    */
    template <class T>
    MetaObjectListElement<T>::~MetaObjectListElement()
    {
        if (this->element_->next_)
            this->element_->next_->prev_ = this->element_->prev_;
        else
            this->list_->last_ = this->element_->prev_; // If there is no next_, we deleted the last object and have to update the last_ pointer of the list

        if (this->element_->prev_)
            this->element_->prev_->next_ = this->element_->next_;
        else
            this->list_->first_ = this->element_->next_; // If there is no prev_, we deleted the first object and have to update the first_ pointer of the list


        COUT(4) << "*** Removing Object from " << ClassIdentifier<T>::getIdentifier()->getName() << "-list." << std::endl;
        delete this->element_;
    }


    // ###############################
    // ###       ObjectList        ###
    // ###############################
    //!  The MetaObjectList contains ObjectListElements and their ObjectLists.
    /**
        The MetaObjectList is a single-linked list, containing all list-elements and their
        lists wherein the object that owns the MetaObjectList is registered.
        This allows much faster deletion of objects because no iteration is needed.
    */
    class MetaObjectList
    {
        public:
            MetaObjectList();
            ~MetaObjectList();
            template <class T>
            void add(ObjectList<T>* list, ObjectListElement<T>* element);

            BaseMetaObjectListElement* first_;      //!< The first element in the list
    };

    /**
        @brief Adds an ObjectList and an element of that list to the MetaObjectList.
        @param list The ObjectList wherein the element is
        @param element The element wherein the object is
    */
    template <class T>
    void MetaObjectList::add(ObjectList<T>* list, ObjectListElement<T>* element)
    {
        BaseMetaObjectListElement* temp = this->first_;
        this->first_ = new MetaObjectListElement<T>(list, element);
        this->first_->next_ = temp;
    }
}

#endif /* _MetaObjectList_H__ */