An abstract adapter class for receiving container events.

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

Extend this class to create a ContainerEvent listener and override the methods for the events of interest. (If you implement the ContainerListener 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 addContainerListener method. When the container's contents change because a component has been added or removed, the relevant method in the listener object is invoked, and the ContainerEvent is passed to it.