Aegisub/aegisub/libmedia/include/libmedia/factory_manager.h

// Copyright (c) 2010, Thomas Goyne <plorkyeran@aegisub.org>
// All rights reserved.
//
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//     this list of conditions and the following disclaimer.
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// Aegisub Project http://www.aegisub.org/
//
// $Id$

/// @file factory_manager.h
/// @brief Template/base-class for factory classes
/// @ingroup utility
///

#pragma once

#ifndef MAGI_PRE
#include <algorithm>
#include <cctype>
#include <map>
#include <vector>
#endif

namespace media {

template <class func>
class FactoryBase {
protected:
	typedef std::map<std::string, std::pair<bool, func> > map;
	typedef typename map::iterator iterator;

	static map *classes;

	static void DoRegister(func function, std::string name, bool hide, std::vector<std::string> &subtypes) {
		if (!classes) classes = new map;

		if (subtypes.empty()) {
			classes->insert(std::make_pair(name, std::make_pair(hide, function)));
		}
		else {
			for (size_t i = 0; i < subtypes.size(); i++) {
				classes->insert(std::make_pair(name + '/' + subtypes[i], std::make_pair(hide, function)));
			}
		}
	}

	static func Find(std::string name) {
		if (!classes) return NULL;

		iterator factory = classes->find(name);
		if (factory != classes->end()) return factory->second.second;
		return NULL;
	}

public:
	static void Clear() {
		delete classes;
	}
	static std::vector<std::string> GetClasses(std::string favourite="") {
		std::vector<std::string> list;
		if (!classes) return list;
		std::string cmp;
		std::transform(favourite.begin(), favourite.end(), favourite.begin(), ::tolower);
		for (iterator cur=classes->begin();cur!=classes->end();cur++) {
			cmp.clear();
			std::transform(cur->first.begin(), cur->first.end(), std::back_inserter(cmp), ::tolower);
			if (cmp == favourite) list.insert(list.begin(), cur->first);
			else if (!cur->second.first) list.push_back(cur->first);
		}
		return list;
	}
	virtual ~FactoryBase() {
		delete classes;
	}
};

template<class Base>
class Factory0 : public FactoryBase<Base *(*)()> {
	typedef Base *(*func)();
	template<class T>
	static Base* create() {
		return new T;
	}
public:
	static Base* Create(std::string name) {
		func factory = FactoryBase<func>::Find(name);
		if (factory) {
			return factory();
		}
		else {
			return NULL;
		}
	}

	template<class T>
	static void Register(std::string name, bool hide = false, std::vector<std::string> subTypes = std::vector<std::string>()) {
		DoRegister(&Factory0<Base>::template create<T>, name, hide, subTypes);
	}
};

template<class Base, class Arg1>
class Factory1 : public FactoryBase<Base *(*)(Arg1)> {
	typedef Base *(*func)(Arg1);
	template<class T>
	static Base* create(Arg1 a1) {
		return new T(a1);
	}
public:
	static Base* Create(std::string name, Arg1 a1) {
		func factory = FactoryBase<func>::Find(name);
		if (factory) {
			return factory(a1);
		}
		else {
			return NULL;
		}
	}

	template<class T>
	static void Register(std::string name, bool hide = false, std::vector<std::string> subTypes = std::vector<std::string>()) {
		DoRegister(&Factory1<Base, Arg1>::template create<T>, name, hide, subTypes);
	}
};

} // namespace media