Bean event communication depends on Java's delegation event model. The delegation event model (introduced with Java 1.1) supplants the old Java 1.0 event model. Three concepts, each associated with an abstract Java class, form the basis of the model:
The event source
The event object
The event listener
Java's delegation event model gets its name from the fact that event sources are delegated out (assigned) to specific event listeners. The result is an efficient event communication system.
Java objects that "fire" events and create event objects are known as event sources. For instance, each graphic user interface component in Java's Abstract Windowing Toolkit is an event source.
Event sources ...