001/*
002 *                    BioJava development code
003 *
004 * This code may be freely distributed and modified under the
005 * terms of the GNU Lesser General Public Licence.  This should
006 * be distributed with the code.  If you do not have a copy,
007 * see:
008 *
009 *      http://www.gnu.org/copyleft/lesser.html
010 *
011 * Copyright for this code is held jointly by the individual
012 * authors.  These should be listed in @author doc comments.
013 *
014 * For more information on the BioJava project and its aims,
015 * or to join the biojava-l mailing list, visit the home page
016 * at:
017 *
018 *      http://www.biojava.org/
019 *
020 */
021
022
023package org.biojava.utils;
024
025
026/**
027 * Interface implemented by ChangeHubs, i.e.
028 * classes that handle behaviour for
029 * multiple instances of Changeable classes.
030 * <p>
031 * Listeners are indexed with a key and when
032 * an event is fired, only listeners with the same
033 * key are invoked.  The class manages the mapping
034 * between key and listener.  It is the users responsibility
035 * to compute the key.
036 *
037 * @author Thomas Down (original implementation)
038 * @author David Huen (refactoring)
039 * @since 1.3
040 */
041public interface ChangeHub
042{
043    /**
044     * add a ChangeListener associated with given key.
045     */
046    public void addListener(Object key, ChangeListener listener, ChangeType ct);
047
048    /**
049     * remove a ChangeListener associated with given key.
050     */
051    public void removeListener(Object key, ChangeListener listener, ChangeType ct);
052
053    /**
054     * invoke the firePreChangeEvent on all ChangeListeners associated with
055     * a specific key.
056     */
057    public void firePreChange(Object key, ChangeEvent cev) throws ChangeVetoException;
058
059    /**
060     * invoke the firePostChangeEvent on all ChangeListeners associated with
061     * a specific key.
062     */
063    public void firePostChange(Object key, ChangeEvent cev);
064}
065