Adding a new type of NSButton

FROM : P Teeson
DATE : Wed Jun 25 21:12:44 2008

Environment is Mac OS X 10.4.11 Xcode 2.5

I need a new type of NSButton/NSButtonCell that I am calling an 
NSLatchButton.
Once it is pushed it stays pushed - pushing it again does not revert 
it back to unpushed state.
(Of course there would be a method to set it to it's unlatched state 
but pushing the button would not
invoke that action)

However I'm not sure how to approach this. Should I use categories, 
extensions, or subclass or what?

If I were dealing with the source code I would add to the button 
types enums
and add a method or case to deal with that type.

But what suggestions do you have?

TIA for your elegant wisdom.....

respect....

Peter