source: code/branches/core/src/orxonox/core/Identifier.h @ 810

/*
 *   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 Identifier.h
    @brief Definition of the Identifier, ClassIdentifier and SubclassIdentifier classes, implementation of the ClassIdentifier and SubclassIdentifier classes.

    The Identifier contains all needed informations about the class it belongs to:
     - the name
     - a list with all objects
     - parents and childs
     - the factory (if available)
     - the networkID that can be synchronised with the server
     - all configurable variables (if available)

    Every object has a pointer to the Identifier of its class. This allows the use isA(...),
    isDirectlyA(...), isChildOf(...) and isParentOf(...).

    To create the class-hierarchy, the Identifier has some intern functions and variables.

    Every Identifier is in fact a ClassIdentifier, but they are derived from Identifier.

    SubclassIdentifier is a separated class, acting like an Identifier, but has a given class.
    You can only assign Identifiers of exactly the given class or of a derivative to a SubclassIdentifier.
*/

#ifndef _Identifier_H__
#define _Identifier_H__

#include <map>
#include <string>
#include <utility>

#include "CorePrereqs.h"

#include "ObjectList.h"
#include "IdentifierList.h"
#include "Debug.h"
#include "Iterator.h"

namespace orxonox
{
    class BaseFactory; // Forward declaration
    class BaseObject;  // Forward declaration

    // ###############################
    // ###       Identifier        ###
    // ###############################
    //! The Identifier is used to identify the class of an object and to store informations about the class.
    /**
        The Identifier contains all needed informations about the class it belongs to:
         - the name
         - a list with all objects
         - parents and childs
         - the factory (if available)
         - the networkID that can be synchronised with the server
         - all configurable variables (if available)

        Every object has a pointer to the Identifier of its class. This allows the use isA(...),
        isDirectlyA(...), isChildOf(...) and isParentOf(...).

        You can't directly create an Identifier, it's just the base-class for ClassIdentifier.
    */
    class _CoreExport Identifier
    {
        template <class T>
        friend class ClassIdentifier;

        template <class T>
        friend class SubclassIdentifier;

        friend class Factory;

        public:
            /** @brief Sets the Factory. @param factory The factory to assign */
            inline void addFactory(BaseFactory* factory) { this->factory_ = factory; }

            BaseObject* fabricate();
            bool isA(const Identifier* identifier) const;
            bool isDirectlyA(const Identifier* identifier) const;
            bool isChildOf(const Identifier* identifier) const;
            bool isParentOf(const Identifier* identifier) const;

            /** @brief Removes all objects of the corresponding class. */
            virtual void removeObjects() const = 0;

            /** @returns the name of the class the Identifier belongs to. */
            inline const std::string& getName() const { return this->name_; }

            /** @returns the parents of the class the Identifier belongs to. */
            inline const IdentifierList& getParents() const { return this->parents_; }

            /** @returns the children of the class the Identifier belongs to. */
            inline IdentifierList& getChildren() const { return *this->children_; }

            /** @returns true, if a branch of the class-hierarchy is being created, causing all new objects to store their parents. */
            inline static bool isCreatingHierarchy() { return (hierarchyCreatingCounter_s > 0); }

            /** @returns the network ID to identify a class through the network. */
            inline const unsigned int getNetworkID() const { return this->classID_; }

            /** @brief Sets the network ID to a new value. @param id The new value */
            void setNetworkID(unsigned int id);

            /** @returns the ConfigValueContainer of a variable, given by the string of its name. @param varname The name of the variable */
            inline ConfigValueContainer* getConfigValueContainer(const std::string& varname)
                { return this->configValues_[varname]; }

            /** @brief Sets the ConfigValueContainer of a variable, given by the string of its name. @param varname The name of the variablee @param container The container */
            inline void setConfigValueContainer(const std::string& varname, ConfigValueContainer* container)
                { this->configValues_[varname] = container; }

        private:
            Identifier();
            Identifier(const Identifier& identifier) {} // don't copy
            virtual ~Identifier();
            void initialize(const IdentifierList* parents);

            /**
                @brief Increases the hierarchyCreatingCounter_s variable, causing all new objects to store their parents.
            */
            inline static void startCreatingHierarchy()
            {
                hierarchyCreatingCounter_s++;
                COUT(4) << "*** Increased Hierarchy-Creating-Counter to " << hierarchyCreatingCounter_s << std::endl;
            }

            /**
                @brief Decreases the hierarchyCreatingCounter_s variable, causing the objects to stop storing their parents.
            */
            inline static void stopCreatingHierarchy()
            {
                hierarchyCreatingCounter_s--;
                COUT(4) << "*** Decreased Hierarchy-Creating-Counter to " << hierarchyCreatingCounter_s << std::endl;
            }

            IdentifierList parents_;                                    //!< The Parents of the class the Identifier belongs to
            IdentifierList* children_;                                  //!< The Children of the class the Identifier belongs to

            std::string name_;                                          //!< The name of the class the Identifier belongs to

            BaseFactory* factory_;                                      //!< The Factory, able to create new objects of the given class (if available)
            bool bCreatedOneObject_;                                    //!< True if at least one object of the given type was created (used to determine the need of storing the parents)
            static int hierarchyCreatingCounter_s;                      //!< Bigger than zero if at least one Identifier stores its parents (its an int instead of a bool to avoid conflicts with multithreading)
            unsigned int classID_;                                      //!< The network ID to identify a class through the network
            std::map<std::string, ConfigValueContainer*> configValues_; //!< A map to link the string of configurable variables with their ConfigValueContainer
    };


    // ###############################
    // ###     ClassIdentifier     ###
    // ###############################
    //! The ClassIdentifier is derived from Identifier and holds all class-specific functions and variables the Identifier cannot have.
    /**
        ClassIdentifier is a Singleton, which means that only one object of a given type T exists.
        This makes it possible to store informations about a class, sharing them with all
        objects of that class without defining static variables in every class.

        To be really sure that not more than exactly one object exists (even with libraries),
        ClassIdentifiers are only created by IdentifierDistributor.

        You can access the ClassIdentifiers created by IdentifierDistributor through the
        ClassManager singletons.
    */
    template <class T>
    class ClassIdentifier : public Identifier
    {
        template <class TT>
        friend class ClassManager;

        public:
            ClassIdentifier<T>* registerClass(const IdentifierList* parents, const std::string& name, bool bRootClass);
            void addObject(T* object);
            void removeObjects() const;
            void setName(const std::string& name);

        private:
            ClassIdentifier();
            ClassIdentifier(const ClassIdentifier<T>& identifier) {}    // don't copy
            ~ClassIdentifier() {}                                       // don't delete

            ObjectList<T>* objects_;    //!< The ObjectList, containing all objects of type T
            bool bSetName_;             //!< True if the name is set
    };

    /**
        @brief Constructor: Creates the ObjectList.
    */
    template <class T>
    ClassIdentifier<T>::ClassIdentifier()
    {
        this->objects_ = ObjectList<T>::getList();
        this->bSetName_ = false;
    }

    /**
        @brief Registers a class, which means that the name and the parents get stored.
        @param parents An IdentifierList, containing the Identifiers of all parents of the class
        @param name A string, containing exactly the name of the class
        @param bRootClass True if the class is either an Interface or the BaseObject itself
        @return The ClassIdentifier itself
    */
    template <class T>
    ClassIdentifier<T>* ClassIdentifier<T>::registerClass(const IdentifierList* parents, const std::string& name, bool bRootClass)
    {
        COUT(4) << "*** Register Class in " << name << "-Singleton." << std::endl;

        // Check if at least one object of the given type was created
        if (!this->bCreatedOneObject_)
        {
            // If no: We have to store the informations and initialize the Identifier
            this->setName(name);

            COUT(4) << "*** Register Class in " << name << "-Singleton -> Initialize Singleton." << std::endl;
            if (bRootClass)
                this->initialize(NULL); // If a class is derived from two interfaces, the second interface might think it's derived from the first because of the order of constructor-calls. Thats why we set parents to zero in that case.
            else
                this->initialize(parents);
        }

        return this;
    }

    /**
        @brief Sets the name of the class.
        @param name The name
    */
    template <class T>
    void ClassIdentifier<T>::setName(const std::string& name)
    {
        if (!this->bSetName_)
        {
            this->name_ = name;
            this->bSetName_ = true;
        }
    }

    /**
        @brief Adds an object of the given type to the ObjectList.
        @param object The object to add
    */
    template <class T>
    void ClassIdentifier<T>::addObject(T* object)
    {
        COUT(4) << "*** Added object to " << this->getName() << "-list." << std::endl;
        object->getMetaList().add(this->objects_, this->objects_->add(object));
    }

    /**
        @brief Removes all objects of the corresponding class.
    */
    template <class T>
    void ClassIdentifier<T>::removeObjects() const
    {
        for (Iterator<T> it = ObjectList<T>::start(); it;)
            delete *(it++);
    }

    // ###############################
    // ###   SubclassIdentifier    ###
    // ###############################
    //! The SubclassIdentifier acts almost like an Identifier, but has some prerequisites.
    /**
        You can only assign an Identifier that belongs to a class T (or derived) to a SubclassIdentifier<T>.
        If you assign something else, the program aborts.
        Because we know the minimal type, a dynamic_cast is done, which makes it easier to create a new object.
    */
    template <class T>
    class SubclassIdentifier
    {
        public:
            /**
                @brief Constructor: Automaticaly assigns the Identifier of the given class.
            */
            SubclassIdentifier()
            {
                std::string name = ClassManager<T>::getName();

                if (name != "unknown")
                    this->subclassIdentifier_ = ClassManager<T>::getIdentifier(name);
                else
                    this->subclassIdentifier_ = 0;

                this->identifier_ = this->subclassIdentifier_;
            }

            /**
                @brief Copyconstructor: Assigns the given Identifier.
                @param identifier The Identifier
            */
            SubclassIdentifier(Identifier* identifier)
            {
                std::string name = ClassManager<T>::getName();

                if (name != "unknown")
                    this->subclassIdentifier_ = ClassManager<T>::getIdentifier(name);
                else
                    this->subclassIdentifier_ = 0;

                this->identifier_ = identifier;
            }

            /**
                @brief Overloading of the = operator: assigns the identifier and checks its type.
                @param identifier The Identifier to assign
                @return The SubclassIdentifier itself
            */
            SubclassIdentifier<T>& operator=(Identifier* identifier)
            {
                if (!identifier->isA(this->subclassIdentifier_))
                {
                    COUT(1) << "Error: Class " << identifier->getName() << " is not a " << this->subclassIdentifier_->getName() << "!" << std::endl;
                    COUT(1) << "Error: SubclassIdentifier<" << this->subclassIdentifier_->getName() << "> = Class(" << identifier->getName() << ") is forbidden." << std::endl;
                    COUT(1) << "Aborting..." << std::endl;
                    abort();
                }
                this->identifier_ = identifier;
                return *this;
            }

            /**
                @brief Overloading of the * operator: returns the assigned identifier.
                @return The assigned identifier
            */
            Identifier* operator*()
            {
                return this->identifier_;
            }

            /**
                @brief Overloading of the -> operator: returns the assigned identifier.
                @return The assigned identifier
            */
            Identifier* operator->() const
            {
                return this->identifier_;
            }

            /**
                @brief Creates a new object of the type of the assigned Identifier and dynamic_casts it to the minimal type given by T.
                @return The new object
            */
            T* fabricate()
            {
                BaseObject* newObject = this->identifier_->fabricate();

                // Check if the creation was successful
                if (newObject)
                {
                    // Do a dynamic_cast, because an object of type T is much better than of type BaseObject
                    return (T*)(newObject);
                }
                else
                {
                    // Something went terribly wrong
                    if (this->identifier_)
                    {
                        COUT(1) << "Error: Class " << this->identifier_->getName() << " is not a " << this->subclassIdentifier_->getName() << "!" << std::endl;
                        COUT(1) << "Error: Couldn't fabricate a new Object." << std::endl;
                        COUT(1) << "Aborting..." << std::endl;
                    }
                    else
                    {
                        COUT(1) << "Error: Couldn't fabricate a new Object - Identifier is undefined." << std::endl;
                        COUT(1) << "Aborting..." << std::endl;
                    }

                    abort();
                }
            }

            /** @returns the assigned identifier. */
            inline const Identifier* getIdentifier() const
                { return this->identifier_; }

            /** @returns true, if the assigned identifier is at least of the given type. @param identifier The identifier to compare with */
            inline bool isA(const Identifier* identifier) const
                { return this->identifier_->isA(identifier); }

            /** @returns true, if the assigned identifier is exactly of the given type. @param identifier The identifier to compare with */
            inline bool isDirectlyA(const Identifier* identifier) const
                { return this->identifier_->isDirectlyA(identifier); }

            /** @returns true, if the assigned identifier is a child of the given identifier. @param identifier The identifier to compare with */
            inline bool isChildOf(const Identifier* identifier) const
                { return this->identifier_->isChildOf(identifier); }

            /** @returns true, if the assigned identifier is a parent of the given identifier. @param identifier The identifier to compare with */
            inline bool isParentOf(const Identifier* identifier) const
                { return this->identifier_->isParentOf(identifier); }

        private:
            Identifier* identifier_;            //!< The assigned identifier
            Identifier* subclassIdentifier_;    //!< The identifier of the subclass
    };
}

#endif /* _Identifier_H__ */