An abstract adapter class for receiving window events.
The methods in this class are empty. This class exists as
convenience for creating listener objects.
Extend this class to create a
and override the methods for the events of interest. (If you implement the
WindowListener 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 Window using the window's
method. When the window's status changes by virtue of being opened,
closed, activated or deactivated, iconified or deiconified,
the relevant method in the listener
object is invoked, and the
WindowEvent is passed to it.