NSButton Subclass - 2 states plus tracking image

FROM : Trygve Inda
DATE : Sat Feb 23 13:19:26 2008

I need an NSButton with 5 different graphics and two states:

State 0  (enabled & disabled graphics)
State 1  (enabled & disabled graphics)
Pressed/Tracking state

I was thinking to subclass NSButton and in IB use "Momentary Change" so that
I can set the alt image to always be my Pressed/Tracking state and the
subclass will change the main image to one of the other 4 images as needed.

The problem I see is that Momentary Change buttons are really single state
so I think my action method for the button would have to also toggle a value
variable and I may need to override value/setValue to use my custom value.

If I set up a two state button, how can I provide a custom tracking image...
Eg when drawRect is called, how can I tell that my button is being pressed
and tracked?

Is there an existing class out there that will just do this? I haven't come
across one.

Thanks,

Trygve