[news.eclipse.platform.swt] How to handle window closing event?

[ewing@xxxxxxxxx (Bill Ewing)]

In our JFace app, we have an action for the traditional "File, Exit."  In 
it, we save some properties to a file.

When we close our app using the X button in the upper right corner of the 
window, however, this action does not get invoked.

How do we trap this event?   

And, is there a way to abort closing a window?

TIA, Bill