Button Cell Images

[Christopher Armstrong]

Hi

I think I've written on this before, but I don't remember getting a 
reply so I'll try again. I want to put some images into a theme bundle 
that are to be used as button images for radio buttons and switch 
buttons. It appears the API for this is incomplete. Someone has been 
working on it but I am trying to understand what they were doing.

From what I can see, button images are currently loaded from the Appkit 
bundle by using the +[NSImage imageNamed:] API when -[NSButtonCell 
setButtonType:] is called. I believe the intention is to replace the 
encoding and decoding of system button images with instances of 
NSButtonImageSource; there appears to be some code to do this in 
NSButtonCell.m but it doesn't make any sense. NSButtonImageSource also 
seems incomplete and it isn't clear what role GSTheme plays in this.

My guess is that NSButtonImageSource instances are to be created for 
each type of button (NSRadioButton and NSSwitch), and they are to be put 
where -[NSButtonCell setImage:] is. NSButtonImageSource appears to be a 
hidden class in Cocoa as both QuantumStep and Cocotron have versions of 
it. I don't understand the part where it only gets stored for the 
alternate image (not the main one as well).

Would someone kindly explain what the intention of this is and how it 
should work? I have the time to work on it at the moment but I have no 
idea what should happen.

Cheers
Chris