An abstract adapter class for receiving keyboard events. The methods in this class are empty. This class exists as convenience for creating listener objects.

Extend this class to create a KeyEvent listener and override the methods for the events of interest. (If you implement the KeyListener interface, you have to define all of the methods in it. This abstract class defines null methods for them all, so you can only have to define methods for events you care about.)

Create a listener object using the extended class and then register it with a component using the component's addKeyListener method. When a key is pressed, released, or typed, the relevant method in the listener object is invoked, and the KeyEvent is passed to it.