Util.java

/**
* OLAT - Online Learning and Training<br>
* http://www.olat.org
* <p>
* Licensed under the Apache License, Version 2.0 (the "License"); <br>
* you may not use this file except in compliance with the License.<br>
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing,<br>
* software distributed under the License is distributed on an "AS IS" BASIS, <br>
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br>
* See the License for the specific language governing permissions and <br>
* limitations under the License.
* <p>
* Copyright (c) since 2004 at Multimedia- & E-Learning Services (MELS),<br>
* University of Zurich, Switzerland.
* <hr>
* <a href="http://www.openolat.org">
* OpenOLAT - Online Learning and Training</a><br>
* This file has been modified by the OpenOLAT community. Changes are licensed
* under the Apache 2.0 license as the original file.  
* <p>
*/ 
package org.olat.core.gui.dev;

import java.util.List;

import org.olat.core.gui.components.Component;
import org.olat.core.gui.components.ComponentEventListener;
import org.olat.core.gui.control.Controller;

/**
 * Description:<br>
 * Util class
 * 
 * <P>
 * Initial Date: 16.03.2007 <br>
 * @author Felix Jost, http://www.goodsolutions.ch
 */
public class Util {
	/**
	 * returns the listener of a component. by legacy this could be more than one, but in practice it is never more than one, and it is also discouraged to have more than one listener, since then there would be no clear responsibility for a component.
	 * @param comp
	 * @return
	 */
	public static Controller getListeningControllerFor(Component comp) {
		Controller c = null;
		List<ComponentEventListener> listeners = comp.debuginfoGetListeners();
		if (listeners.size() > 0) {
			// legacy, in future a component may only have one listener (in practice no component ever uses more than one listener; one listener = assigned responsability) 
			for(ComponentEventListener listener:listeners) {
				if(listener instanceof Controller) {
					c = (Controller)listener;
					break;
				}
			}
		}
		return c;
	}
}