Java Event Handling

Adapter Classes for Listener Interfaces

Any class which handles events must implement a listener interface for the event type it wishes to handle. A class can implement any number of listener interfaces. To implement a listener interface the class must implement every method in the interface. Sometimes you may want to implement only one or two of the methods in an interface. You can avoid having to write your own implementation of all the methods in an interface by using an adapter class. An adapter class is a class that already implements all the methods in its corresponding interface. Your class must extend the adapter class by inheritance so you can extend only one adapter class in your class (Java does not support multiple inheritance). Here are the Java adapter classes and the listener interfaces they implement. Notice that adapters exist for only listener interfaces with more than one method.

Adapter Class Listener Interface

ComponentAdapter ComponentListener

ContainerAdapter ContainerListener

FocusAdapter FocusListener

KeyAdapter KeyListener

MouseAdapter MouseListener

MouseMotionAdapter MouseMotionListener

WindowAdapter WindowListener

---