libreccm-legacy/ccm-core/src/com/arsdigita/domain/GlobalObserverManager.java

84 lines
2.5 KiB
Java
Executable File

/*
* Copyright (C) 2001-2004 Red Hat Inc. All Rights Reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
package com.arsdigita.domain;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.log4j.Logger;
/**
* The GlobalObserverManager class is a singleton class that allows observers
* implementing the GlobalObserver interface to be registered.
*
* Once such observers are registered they have the opportunity to observe
* every single observable domain object that is created. The
* GlobalObserver.shouldObserve(DomainObject) method can be used by an observer
* to select which objects to observe.
*
* @author <a href="mailto:rhs@mit.edu">rhs@mit.edu</a>
* @version $Id: GlobalObserverManager.java 2070 2010-01-28 08:47:41Z pboy $
*/
public class GlobalObserverManager {
private static final GlobalObserverManager s_manager =
new GlobalObserverManager();
/**
* Returns the global observer manager. This is a singleton class that
* allows the "global" observers, or observers of any
*/
public static final GlobalObserverManager getManager() {
s_log.debug("getInstance of GlobalObserverManager invoked.");
return s_manager;
}
private static final Logger s_log = Logger.getLogger(GlobalObserverManager.class);
private List m_observers = new ArrayList();
private GlobalObserverManager() {}
/**
* Adds a new observer.
*
* @param doo the new observer
*/
public void addObserver(GlobalObserver go) {
s_log.debug("addObserver invoked.");
m_observers.add(go);
}
/**
* Returns the global observers.
*
* @return The observers for the given domain object.
*/
Iterator getObservers() {
return m_observers.iterator();
}
}