[Tutor] Dynamically changing the state of a button

[Suzanne Little]

Hello, 

I decided to put this in a separate post since it really is two separate
problems. For details on the general project and some sample code please
see my previous post (How do I update a listbox?). I need to change the
state option of buttons from disabled to normal depending upon whether an
item is selected in a listbox. The things I've tried have been to bind an
event to clicking the mouse in the listbox which causes a test of whether
an item is selected and if so calls a function to remake the button frame
and change the states. It does this by first destroying the button frame
and then calling the make function and passing a value  
(normal/disabled). Obviously this is really messy and it doesn't work. The
bind/event doesn't notice that an item has been selected until the second
time you click and destroying/recreating the button frame looks 
awful. I've been reading around on python.org and my best guess is that I
might need to do something with after_idle() and update() but I don't
understand how either of these work. I need to extend this a bit as well
(one button should only be enabled if a certain type of element is
selected). 

If you're still with me after that rather confusing explanation, any
suggestions would be greatly appreciated.

Thanks,

Suzanne

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"Contrariwise," continued Tweedledee, "If it was so, it might be; and if
it were so, it would be; but as it isn't, it ain't.  That's logic"
                             -Lewis Carroll
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