Putting a spinning progress indicator in a outline

FROM : Markus Spoettl
DATE : Fri Aug 01 23:49:47 2008

Hello List,

  I'm trying to figure out how I might be able to do something like 
Mail.app does displaying a spinning progress indicator as part of an 
outline item. Is this a custom cell type that AppKit doesn't have or 
is it something that's already there waiting to be used? I'd be 
grateful is someone could push me in the right direction.

Thanks!
Regards
Markus
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