Re: [Pyobjc-dev] UI bindings no longer work for me

[Jason F. <ja...@th...>]

On Aug 31, 2009, at 10:12 PM, Mani Ghasemlou wrote:
> I have an NSImageView, whose Hidden state is bound to a variable of my
> app delegate. Clicking the "Show" button sets this value to False, and
> "Hide" sets this value to True.
>
> Using Snow Leopard, the NSImageView's Hidden state does not change
> when clicking these buttons. Using Leopard, the image shows and hides
> itself depending on the button pressed.
>
> Can someone help me understand what I might be doing wrong?


I'm sure someone with more PyObjC experience can give you a better  
answer, but here's my findings:

There seems to be an issue with the way you initialize your app  
delegate and KVC/KVO.  If you change your calls like  
"self.hideComputer = False" to "self.setValue_forKey_(False,  
'hideComputer')" it starts working.  Similarly, you can override the  
app delegate's init method, and this seems to setup KVC correctly for  
the hideComputer field:

class BindingsUITestAppDelegate(NSObject):
     # hideComputer = ivar('hideComputer')
     def init(self):
         self.hideComputer = False
         return self
     .... etc


I don't have any idea why this is, and am anxious myself to hear an  
explanation from the gurus.  But in the meantime this might be a  
suitable workaround for you.


Jason