north - east - south - west selector using NSMatrix?

FROM : patrick machielse
DATE : Tue Aug 29 23:19:30 2006

I'm trying to implement a control area for selecting a direction 
(north - east - south - west, or top - right - bottom - left). Only 
one of these choices can be selected at one time.

My first try was to use an NSMatrix with radio buttons. In IB I 
created a 3x3 matrix of radio buttons and I disabled and made 
transparent the buttons at indeces 0, 2, 4, 6, and 8. The problem is 
that I can still 'select' the buttons at these indexes by clicking on 
their locations, in which case none of the enabled and visible radio 
buttons is selected.

Since this type of control seems fairly common, I was wondering what 
solutions other people are using, and if there is a better way to do 
it than I'm using now (I suppose so!).

patrick