/*
 * GNU LESSER GENERAL PUBLIC LICENSE Copyright (C) 2006 The Lobo Project
 * 
 * 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.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 * 
 * Contact info: lobochief@users.sourceforge.net
 */
/*
 * Created on Mar 19, 2005
 */
package com.nvarghese.beowulf.common.cobra.util;

import java.util.ArrayList;
import java.util.Collection;
import java.util.EventListener;
import java.util.EventObject;

/**
 * @author J. H. S.
 */
public abstract class EventDispatch2 {

	private Collection listeners;
	private static final EventListener[] EMPTY_ARRAY = new EventListener[0];

	public EventDispatch2() {

	}

	public Collection createListenerCollection() {

		return new ArrayList();
	}

	public final void addListener(EventListener listener) {

		synchronized (this) {
			if (this.listeners == null) {
				this.listeners = this.createListenerCollection();
			}
			this.listeners.add(listener);
		}
	}

	public final void removeListener(EventListener listener) {

		synchronized (this) {
			if (this.listeners != null) {
				this.listeners.remove(listener);
			}
		}
	}

	public final boolean fireEvent(EventObject event) {

		EventListener[] larray;
		synchronized (this) {
			Collection listeners = this.listeners;
			if (listeners == null || listeners.size() == 0) {
				return false;
			}
			larray = (EventListener[]) this.listeners.toArray(EMPTY_ARRAY);
		}
		int length = larray.length;
		for (int i = 0; i < length; i++) {
			// Call holding no locks
			this.dispatchEvent(larray[i], event);
		}
		return true;
	}

	protected abstract void dispatchEvent(EventListener listener, EventObject event);
}