medical image analysis SVN (old)

/*
** Copyrigh (C) 1999-2004 Max-Planck-Institute of Cognitive Neurosience
**  
** 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

  As an exception to this license, "NEC C&C Research Labs" may use
  this software under the terms of the GNU Lesser General Public License as
  published by the Free Software Foundation.
   
*/

// $Id: factory.hh,v 1.4 2005/06/03 11:00:38 gerddie Exp $

/** 
    \author: Gert Wollny < wollny at cbs mpg de >
    implements a plugin loading factory
*/

#ifndef FACTORY_HH
#define FACTORY_HH

#include <iostream>
#include <memory>
#include <boost/shared_ptr.hpp>

#include <mia/core/handler.hh>
#include <mia/core/msgstream.hh>
#include <mia/core/plugin_base.hh>
#include <mia/core/optionparser.hh>

NS_MIA_BEGIN

/** this is the class to load a certain plugin */
template <typename P, typename D, typename T>
class TFactory: public TPlugin<D,T> {
public: 
	typedef P Product; 
	typedef boost::shared_ptr<P> ProductPtr; 
	
	/** initialise the plugin by the names 
	    \remark what are these names and types good for?
	*/
	TFactory(char const * const  name);
	
	/** the creation function 
	    \params options the options to initialise the plugin 
	    \returns an instance of the requested object
	*/
	virtual ProductPtr create(const CParsedOptions& options);
	
	/** this is the important part  of the plugin loading mechanism:
	    \param params is a string that describes the options for loading the plugin
	    \param ph is the handler of a certain kind of plugins 
	    \returns a entitity of the requested functionallity 
	*/
	
	template <class  H>
	static ProductPtr produce(char const *params, const H& ph)
	{
		CComplexOptionParser param_list(params);
		
		if (param_list.size() < 1) 
			return ProductPtr(); 
		
		const std::string& factory_name = param_list.begin()->first; 
		cvdebug() << "TFactory<>::produce: Create plugin from '" << factory_name << "'\n"; 

		if (factory_name == plugin_help) {
			cvdebug() << "wait for the help\n"; 
			ph.print_help(std::cerr);
			return ProductPtr(); 
		}

		typename H::Interface *factory = ph.plugin(factory_name.c_str());
		if (factory)
			return factory->create(param_list.begin()->second);
		else 
			return ProductPtr(); 
	}

	/// a selftest function, actual implementation in \a do_test 
	void test() const; 

private:
	virtual void do_test() const = 0; 
	virtual ProductPtr do_create() = 0;
};


template <typename P, typename D, typename T>
TFactory<P,D,T>::TFactory(char const * const  name):
	TPlugin<D,T>(name)
{
}

template <typename P, typename D, typename T>
typename TFactory<P,D,T>::ProductPtr TFactory<P,D,T>::create(const CParsedOptions& options)
{
	this->set_parameters(options);
	this->check_parameters();
	return this->do_create(); 
}

template <typename P, typename D, typename T>
void TFactory<P,D,T>::test() const
{
	this->do_test(); 
}

NS_MIA_END
#endif

/*
  $Log: factory.hh,v $
  Revision 1.4  2005/06/03 11:00:38  gerddie
  add log entries to all files

*/