Graphic Java™ 1.2, Volume I: AWT, Third Edition

Firing AWT Events from Custom Components

A good percentage of AWT components fire some sort of semantic event. Likewise, many custom components perform one or more actions that could be construed as semantic events. Equipping a custom component to fire semantic events is a fairly common and, thankfully, straightforward task that can be enumerated as follows:

1. Have the component implement a listener interface, if appropriate.

2. Add an appropriate listener member to the class.

3. Implement addXXXListener() and removeXXXListener().

4. Implement processXXXEvent().

Example 9-25 lists the ThreeDButton class modified to fire action events under the same circumstances that java.awt.Button does.

Example 9-25. ThreeDButton That Fires Action Events

import java.applet.Applet; ...