Core Java - [Java Adapter Classes]

♠ Posted by Unknown in Core Java at 10:52

Java Adapter Classes

Java provides a special features, called an adapter class, that can simplify the creation of event handlers in certain situations. An adapter class provides an empty implementation of all methods in an event listener interface. You can define a new class to act as an event listener by extending one of the adapter classes and implementing only those events in which you are interested.

For example, the "MouseMotionAdapter" class has two methods, mouseDragged() and mouseMoved(). The signatures of these empty methods are exactly as defined in the "MouseMotionListener" interface. If you were interested in only mouse drag events, then you could simply extend "MouseMotionAdapter" and implement mouseDragged(). The empty implementation of mouseMoved() would handle the mouse motion events for you.

Adapter Class                         Listener Interface

ComponentAdapter                ComponentListener

ContainerAdapter                   ContainerListener

FocusAdapter                         FocusListener

KeyAdapter                            KeyListener

MouseAdapter                        MouseListener

MouseMotionAdapter              MouseMotionListener

WindowAdapter                     WindowListener