Instances of this class provide a description of a particular
event which occurred within SWT. The SWT untyped listener
API uses these instances for all event dispatching.
Note: For a given event, only the fields which are appropriate
will be filled in. The contents of the fields which are not used
by the event are unspecified.
Note: For a given event, only the fields which are appropriate will be filled in. The contents of the fields which are not used by the event are unspecified.