dynamicfactory.h

This software aims to create an applet and panel tools to manage a wireless interface card, such as

//
// DynamicFactory.h
//
// $Id: //poco/Main/Foundation/include/Foundation/DynamicFactory.h#1 $
//
// Definition of the DynamicFactory class.
//
// Copyright (c) 2004-2005, Guenter Obiltschnig/Applied Informatics.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// 3. Redistributions in any form must be accompanied by information on
//    how to obtain complete source code for this software and any
//    accompanying software that uses this software.  The source code
//    must either be included in the distribution or be available for no
//    more than the cost of distribution plus a nominal fee, and must be
//    freely redistributable under reasonable conditions.  For an
//    executable file, complete source code means the source code for all
//    modules it contains.  It does not include source code for modules or
//    files that typically accompany the major components of the operating
//    system on which the executable file runs.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//


#ifndef Foundation_DynamicFactory_INCLUDED
#define Foundation_DynamicFactory_INCLUDED


#ifndef Foundation_Foundation_INCLUDED
#include "Foundation/Foundation.h"
#endif
#ifndef Foundation_ObjectFactory_INCLUDED
#include "Foundation/ObjectFactory.h"
#endif
#ifndef Foundation_Exception_INCLUDED
#include "Foundation/Exception.h"
#endif
#ifndef Foundation_Mutex_INCLUDED
#include "Foundation/Mutex.h"
#endif
#ifndef STD_MAP_INCLUDED
#include <map>
#define STD_MAP_INCLUDED
#endif
#ifndef STD_MEMORY_INCLUDED
#include <memory>
#define STD_MEMORY_INCLUDED
#endif


Foundation_BEGIN


template <class Base>
class DynamicFactory
	/// A factory that creates objects by class name.
{
public:
	typedef AbstractObjectFactory<Base> AbstractFactory;

	DynamicFactory()
		/// Creates the DynamicFactory.
	{
	}

	~DynamicFactory()
		/// Destroys the DynamicFactory and deletes the object factories for 
		/// all registered classes.
	{
		for (typename FactoryMap::iterator it = _map.begin(); it != _map.end(); ++it)
		{
			delete it->second;
		}
	}
	
	Base* createInstance(const std::string& className) const
		/// Creates a new instance of the class with the given name.
		/// The class must have been registered with registerClass.
		/// If the class name is unknown, a NotFoundException is thrown.
	{
		FastMutex::ScopedLock lock(_mutex);

		typename FactoryMap::const_iterator it = _map.find(className);
		if (it != _map.end())
			return it->second->createInstance();
		else
			throw NotFoundException(className);
	}
	
	template <class C> 
	void registerClass(const std::string& className)
		/// Registers the object factory for the given class with the DynamicFactory.
		/// The DynamicFactory takes ownership of the abstract factory and deletes
		/// it when it's no longer used.
		/// If the class has already been registered, an ExistsException is thrown
		/// and the object factory is deleted.
	{
		registerClass(className, new ObjectFactory<C, Base>);
	}
	
	void registerClass(const std::string& className, AbstractFactory* pAbstractFactory)
		/// Registers the object factory for the given class with the DynamicFactory.
		/// The DynamicFactory takes ownership of the abstract factory and deletes
		/// it when it's no longer used.
		/// If the class has already been registered, an ExistsException is thrown
		/// and the object factory is deleted.
	{
		poco_check_ptr (pAbstractFactory);

		FastMutex::ScopedLock lock(_mutex);

		std::auto_ptr<AbstractFactory> ptr(pAbstractFactory);
		typename FactoryMap::iterator it = _map.find(className);
		if (it == _map.end())
			_map[className] = ptr.release();
		else
			throw ExistsException(className);
	}
	
	void unregisterClass(const std::string& className)
		/// Unregisters the given class and deletes the object factory
		/// for the class.
		/// Throws a NotFoundException if the class has not been registered.
	{
		FastMutex::ScopedLock lock(_mutex);

		typename FactoryMap::iterator it = _map.find(className);
		if (it != _map.end())
		{
			delete it->second;
			_map.erase(it);
		}
		else throw NotFoundException(className);
	}
	
	bool isClass(const std::string& className) const
		/// Returns true iff the given class has been registered.
	{
		FastMutex::ScopedLock lock(_mutex);

		return _map.find(className) != _map.end();
	}

private:
	DynamicFactory(const DynamicFactory&);
	DynamicFactory& operator = (const DynamicFactory&);

	typedef std::map<std::string, AbstractFactory*> FactoryMap;
	
	FactoryMap _map;
	mutable FastMutex _mutex;
};


Foundation_END


#endif // Foundation_DynamicFactory_INCLUDED