001 package sale.events;
002
003 import util.*;
004
005 /**
006 * An abstract adapter class for receiving timer events. The methods in this
007 * class are empty. This class exists as convenience for creating listener objects.
008 *
009 * <p>Extend this class to create a TimerEvent listener and override the methods
010 * for the events of interest. (If you implement the TimerListener interface, you
011 * have to define all of the methods in it. This abstract class defines empty method bodies for
012 * them all, so you can concentrate on defining methods only for events you care about.)</p>
013 *
014 * <p>Create a listener object using the extended class and then register it with a
015 * Timer using the Timer's {@link sale.Timer#addTimerListener} method. When a timer event occurs, the relevant
016 * method in the listener object is invoked, and a {@link TimerEvent} is passed to it.</p>
017 *
018 * @author Steffen Zschaler
019 * @version 2.0 18/08/1999
020 * @since v2.0
021 */
022 public abstract class TimerAdapter extends Object implements TimerListener, SerializableListener {
023
024 /**
025 * Invoked when the time has been set.
026 *
027 * @param tevtEvent the TimerEvent to process
028 *
029 * @override Sometimes
030 */
031 public void onTimeSet(TimerEvent tevtEvent) {}
032
033 /**
034 * Invoked when the interval has been set.
035 *
036 * @param tevtEvent the TimerEvent to process
037 *
038 * @override Sometimes
039 */
040 public void onIntervalSet(TimerEvent tevtEvent) {}
041
042 /**
043 * Invoked when the time has been increased.
044 *
045 * @param tevtEvent the TimerEvent to process
046 *
047 * @override Sometimes
048 */
049 public void onGoneAhead(TimerEvent tevtEvent) {}
050 }