dynclass.h

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#ifndef __DYNAMIC_H__
#define __DYNAMIC_H__

#include <cstdio>
#include <string>
#include <typeinfo>

#if !defined ( DYN_DECLARE ) 
	#define DYN_DECLARE(class_name)  DYN_CLASS::CFactory<class_name> class_name 
#endif

#if !defined ( DYN_CREATE ) 
	#define DYN_CREATE(class_name)   DYN_CLASS::Create(class_name)
#endif
  

namespace DYN_CLASS
{
	/* create object by class name */
    void * Create( const char * class_name );

    /* interface of class factory*/
    class CAbstractFactory
    {
    public:

        virtual void * Create( const char * class_name ) = 0;
    };
    
	/* list of class factory */
    class CFactoryList
    {
        friend void * Create( const char * class_name );
    
        static CFactoryList * _head;
        CFactoryList        * m_next;
        CAbstractFactory    * m_item;

    public:

        CFactoryList( CAbstractFactory * fact );
        virtual ~CFactoryList( void );

    };
    
	/* ctor of CFactoryList, add a class factory to list */
    inline CFactoryList::CFactoryList( CAbstractFactory * fact )
                            : m_item( fact )
    {
        m_next = _head;
        _head = this;
    }

#if defined ( _MSC_VER )
	/* disable warning for the following line : factory( void ): m_item( this ) {} */
    #pragma  warning(disable : 4355)
#endif

	/* realization of class factory */
    template <class t>
    class CFactory: public CAbstractFactory
    {
        static t     _object;
        CFactoryList m_item;
                                                      
    public:
 
		/* add itself to list of class factory when constructed */
        CFactory( void ) : m_item( this ) {}
        
        virtual ~CFactory() {}

		/* create object of this class if matched */
        void * Create( const char * class_name )
        {
			std::string strClassName;
			
#if defined (WIN32 )			
			strClassName = ( "class " );
#else
            char szSize[4] = {0};
            sprintf(szSize, "%d", strlen(class_name) );
			strClassName = szSize;
#endif			
            strClassName += class_name;

			/* RTTI support */
            return !strcmp( typeid(_object).name(), strClassName.c_str() )
                    ? (void*)( new t ) : 0 ;
                    
        }
    };
}
#endif /* __DYNAMIC_H__ */