[Tkinter-discuss] Public properties in Tkinter superclasses?

[Douglas S. Blank]

I'm not a Tkinter expert, but I have run into a similar problem that was 
caused by the class not being based on the new style "object". You might 
try:

class MyButton(Button, object):

to see if you get properties to work. But maybe I'm completely off the 
mark, and a tkinter expert will give you better information.

-Doug

Jeff Cagle wrote:
> Hi all,
> 
>   I wrote a small "can you match the color?" program.  The user is 
> confronted with a 4-bit/chan. color code such as '#3F6' and must click 
> the button out of six whose color matches the code.  Feedback in the 
> form of 'that color is #8D2' is given.  There is also a Reset button so 
> that the user can try a different panel of six colors when he desires.
> 
> Anyways, because I needed each button to display different feedback, I 
> ended up inheriting from the Button base class.  The original intent was 
> to create a color public property that could be set and gotten:
> 
> ----
> class MyButton(Button):
> 
>     HEX = "0123456789ABCDEF"
>    
>     def __init__(self, master):
>         self.color = self.rand_color()
>         Button.__init__(self, master, \
>                         fg=self.color,\
>                         bitmap="gray75",\
>                         width=50,\
>                         command = self.report)
>        def get_color(self):
>            return self['fg']
>  
>       def set_color(self, color):
>            self['fg'] = color
>  
>       color = property(get_color, set_color)
> 
>     def rand_color(self):
>         return '#' + ''.join([random.choice(self.HEX) for x in range(3)])
>    
>     def report(self):
>         Answer.set("That color is %s" % self.color)
> ----
> 
> Oddly, though, the get_color and set_color methods did not work properly 
> on Reset.  For the first run, the colors are set and gotten correctly.  
> But if the reset code is called,
> 
> ----
> def restart(self):
>         for x in self.buttons:
>             x.color = x.rand_color()
>         s = random.choice(self.buttons).color
>         self.update()
>         self.set_display(s)
> ----
> 
> the new colors are not set.  Further, if new colors are assigned 
> manually, the call to get_color() returns the originally assigned 
> color.  BUT, if I comment out the set_ and get_ methods and the 'color = 
> property()' line, and allow color to be a normal private property, then 
> this works to assign new colors:
> 
> ----
> def restart(self):
>         for x in self.buttons:
>             x.color = x.rand_color()
>             x['fg'] = x.color
>         s = random.choice(self.buttons).color
>         self.update()
>         self.set_display(s)
> ----
> 
> The only difference appears to be that I'm manually calling x['fg'] 
> instead of relying on set_color() to do so for me.  I can't fathom why 
> that would make a difference.
> 
> Do Tkinter classes not allow for property() s?
> 
> Thanks,
> Jeff
> 
> 
> 
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