[Drawkit] DKKnob

[V1ru8]

Hi,

I'm trying to customize the Knobs. So I subclass DKKnob and implements  
some of the methods. Like fillColourForKnobType: and  
knobPathAtPoint:ofType:angle:userInfo:. That let me change the color  
and geometry of a few knobs (the ones to rotate and the ones to resize  
(only geometry). But I can't change the geometry nor change the color  
of the yellow one in the middle (to move the content). How can I  
change them? How can I change the color of the resize knobs?
For me it looks like the API to change the knobs isn't very  
consistent. Because when I see a method like "-  
(NSColor*)fillColourForKnobType:(DKKnobType) knobType" I assume that I  
can change the color of all knobs with it. Or is there something I  
should now about the knob system which brings a bit more clarity in?

Thank you in advance for some advices.

Thomas