[news.eclipse.platform.swt] Use swt's progressbar during long period ope

[handong@xxxxxxxxxxxxx (handong)]

i have a appcation that make a long period operation.(zip files) so,i want 
to show a swt's progressbar to user when they must waiting for result.
but how can i control progressbar's action , make it  disappeared 
automatically when the long period operation is over?

does i must use thread?