ChangeListener Event listener interface for ChangeEvent
CompletionListener Event listener interface for CompletionEvent
DriveEvent Base interface implemented by all Drive event types. 
ResourceEvent Base interface for DriveEvent types related to a specific resource. 


ChangeEvent Sent when a DriveResource has had a change to its DriveContents or Metadata
CompletionEvent An event delivered after the client requests a completion notification using setNotifyOnCompletion(boolean) and that action has either succeeded or failed on the server. 
DriveEventService Abstract base class for a bound service that handles Drive events.