#ifndef CREATABLE_H
#define CREATABLE_H
///////////////////////////////////////////////////////////////////////
//  creatable.h  -  declares creatable interface and object factory  //
//  ver 1.0                                                          //
//  Language:       Visual C++, ver 6.0, SP 5                        //
//  Platform:       Dell Dimension 8100, Win 2000 Pro, SP 2          //
//  Application:    CSE691/791 - SWM&A Demonstration                 //
//  Author:         Jim Fawcett, CST 2-187, Syracuse Univ            //
//                  (315) 443-3948, jfawcett@twcny.rr.com            //
///////////////////////////////////////////////////////////////////////
/*
    Module Operations:
    ==================
    The creatable class defines an interface for objects that can be
    created with an instance of class objFactory.  Creatable classes
    inherit from the creatable interface and implement three functions:
      - a constructor that registers the class with objFactory
      - a create function that returns a new instance of the class
        via a creatable pointer.
      - a function called classID() that returns a string holding the
        class name.
    Usually, we declare a static global instance of every class to be
    manufactured by objFactory.  Because they are static, their con-
    structors are called before main is entered, so any instance of
    objFactory has all the classes registered when your code begins to
    execute.

    Public Interface of creatable and objFactory classes
    ====================================================
    objFactory factory;
    myCreatable *pMyCr 
      = dynamic_cast<myCreatable*>(factory.makeObj("myCreatable");
    pMyCr->memberfun();
    delete pMyCr;

*/
//

/////////////////////////////////////////////////////////////////////////
//  build process                                                      //
/////////////////////////////////////////////////////////////////////////
//  required files:                                                    //
//    creatable.h, creatable.cpp                                       //
//                                                                     //
//  compiler command:                                                  //
//    cl /GX /GR /DTEST_CREATABLE creatable.cpp                        //
//                                                                     //
//  note: /GR enables RTTI which we need in order to use dynamic_cast. //
//        In the IDE you can enable RTTI on the Project Settings       //
//        menu.  Select C/C++ tab and select C++ language from the     //
//        category combo box.  Check the box for enabling RTTI.        //
//                                                                     //
/////////////////////////////////////////////////////////////////////////
/*
    Maintenance History
    ===================
    ver 1.0 : 01 Dec 01
      - first release

*/

//

#pragma warning(disable : 4786)
#include <string>
#include <map>

/////////////////////////////////////////////////////////////////////////
//  creatable interface declaration

typedef std::string classID;

class creatable {

  public:
    virtual ~creatable() { }
    static  creatable* create();
    virtual classID id() const = 0;
};

/////////////////////////////////////////////////////////////////////////
//  createFunc is a typedef for a pointer to a function with the
//  signature: creatable* create()
//  This function returns a new instance of a creatable class.

typedef creatable*(*createFunc)();    // Stroustrup, pg 420

/////////////////////////////////////////////////////////////////////////
//  registryType is the type of a map which holds pairs where the key
//  is a class name string and value is a pointer to a create function

typedef std::map<classID, createFunc> registryType;

/////////////////////////////////////////////////////////////////////////
//  objFactory class declaration

class objFactory {

  public:
    void reg(classID id, createFunc pFun);
    creatable* makeObj(classID id);

  private:
    static registryType registry;
};

#endif