<?php
/**
 *  Copyright (C) 2010  Kai Dorschner
 *
 *  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/>.
 *
 * @author Kai Dorschner <the-hide@address.com>
 * @copyright Copyright 2010, Kai Dorschner
 * @license http://www.gnu.org/licenses/gpl.html GPLv3
 * @package mocovi
 */

class_exists('MvcException')	or require $GLOBALS['library'].'autoload/MvcException.php';

/**
 * A generic Event object like in ActionScript or else.
 * 
 * It produces events sent to eventListener objects.
 *
 * @package mocovi
 */
class EventHandler
{
	protected static $listeners = array();

	protected function __construct()
	{
		throw new MvcException(get_class($this).' cannot be instantiated. It\'s a static class.');
	}

	public static final function observe($event, $namespace, EventListener $listener)
	{
		if(!isset(self::$listeners[$namespace]))
			self::$listeners[$namespace] = array();
		if(!isset(self::$listeners[$namespace][$event]))
			self::$listeners[$namespace][$event] = array();
		self::$listeners[$namespace][$event][] = $listener;
	}

	public static final function triggerEvent($event, &$context)
	{
		if(!isset(self::$listeners[$namespace = get_class($context)]) || !isset(self::$listeners[$namespace][$event]))
			return false;
		foreach(self::$listeners[$namespace][$event] as $listener)
			$listener->triggerEvent($context);
	} 
}