| An abstract adapter class for receiving drag source events. The methods in
this class are empty. This class exists only as a convenience for creating
listener objects.
Extend this class to create a DragSourceEvent listener
and override the methods for the events of interest. (If you implement the
DragSourceListener interface, you have to define all of
the methods in it. This abstract class defines null methods for them
all, so you only have to define methods for events you care about.)
Create a listener object using the extended class and then register it with
a DragSource. When the drag enters, moves over, or exits
a drop site, when the drop action changes, and when the drag ends, the
relevant method in the listener object is invoked, and the
DragSourceEvent is passed to it.
The drop site is associated with the previous dragEnter()
invocation if the latest invocation of dragEnter() on this
adapter corresponds to that drop site and is not followed by a
dragExit() invocation on this adapter. | 