[MacRuby-devel] Bindings only working one-way

Michael Winterstein parzival at mindspring.com
Fri Nov 21 16:01:15 PST 2008


I'm having difficulty working with bindings and I'm not sure if it's a  
MacRuby thing or my poor understanding of how they work.

I've tried binding to two types of things - an NSMatrix of radio  
buttons (binding to "selectedTag") and a Checkbox value.

Using just an attr_accessor - the variable changes when the user  
changes them, but changing the variable doesn't update in the UI.

So I added an explicit setter method and to change the variable, I use  
self.setVideoSource(VID_USE_S2) to modify it.

This works to change it on-screen, but now UI changes aren't getting  
through to the variables properly.  The NSMatrix variable isn't  
changing, and the other variables are changing but are no longer  
Boolean.  (If I do a "p x" I get  either #<NSCFBoolean:0xa07f13f8> or  
#<NSCFBoolean:0xa07f1400>.

I tried replacing 'attr_accessor' with 'attr_reader', and adding an  
explicit getter. That results in the following when I run (even if I  
add a 'return nil' to my setter method):

[4169:10b] KVO autonotifying only supports -set<Key>: methods that  
return void. Autonotifying will not be done for invocations of - 
[MainWinController setVideoSource:].

I haven't yet tried manual notification because I'm not likely to use  
bindings for this case if that much work is required.  Is this the  
expected way to go, or am I missing something here?



Here's a bit of the code (these are set as keys in IB).  When used  
elsewhere, I just have them as the instance variable :

attr_accessor	:audioIncludeS1		# whether to include audio
attr_accessor	:audioIncludeS2		# for a particular channel
attr_accessor   	:videoSource		# which source to use (if any) for video
	
def setAudioIncludeS1(value)
     @audioIncludeS1 = value
end

def setAudioIncludeS2(value)
     @audioIncludeS2 = value
end


def setVideoSource(value)
     case value
         when VID_USE_S1
             @videoSource = VID_USE_S1
         when VID_USE_S2
             @videoSource = VID_USE_S2
         when VID_USE_NONE
             @videoSource = VID_USE_NONE
         else
             @videoSource = VID_USE_NONE
     end
end

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.macosforge.org/pipermail/macruby-devel/attachments/20081121/40324018/attachment.html>


More information about the MacRuby-devel mailing list