<?php
/**
 * A registry for several data types and objects. Objects should be added by
 * addInstance() and therefore must implement the interface Registerable.
 *
 * @author		Roland Haeder <webmaster@shipsimu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2016 Core Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.shipsimu.org
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */
class GenericRegistry extends BaseRegistry implements Register {
	/**
	 * Instance of this class
	 */
	private static $registryInstance = NULL;

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);
	}

	/**
	 * Singleton getter for self instance. This class has no factory pattern
	 * because here is no need for special parameters.
	 *
	 * @return	$registryInstance	Instance of this class
	 */
	public static final function getRegistry () {
		// Is an instance there?
		if (is_null(self::$registryInstance)) {
			// Not yet, so create one
			self::$registryInstance = new GenericRegistry();
		} // END - if

		// Return the instance
		return self::$registryInstance;
	}

}