Tkinter, Alt, and Windows

Tim Daneliuk tundra at
Fri Jan 7 18:08:30 EST 2005

Tim Daneliuk wrote:

> Arrrrrggg.  I have a program that runs comfortably across both Unix 
> variants
> and Windows ... except .... I wish to bind an Alt-ButtonRelease-3 
> combination
> to popup a menu.  This works flawlessly under Unix, but with windows,
> the menu appears briefly and then disappears.  I'm guessing that Alt
> under windows generates another event that I am not catching and the
> default internal Tk message handler is processing it and causing my
> menu to get destroyed.
> It seems that any combination involving the Alt key has this issue -
> for example Control-Alt-ButtonRelease-3 does the same thing.
> Has anyone else run into this behavior and have a fix???

I have a partial workaround but the mechanics still mystify me.
I actually was trying to bind two different popup menus to as follows:

Alt-ButtonRelease-3           Menu1
Alt-Control-ButtonRelease-3   Menu2

This did not work ... so I began to wonder if this was problem
with Tk using greedy matching with event descriptors.  So, I changed
it as follows:

Control-ButtonRelease-3       Menu1
Alt-Control-ButtonRelease-3   Menu2

This now works fine, BUT ONLY if Alt is pressed *before* Control when popping up
Menu2.  IOW Windows is sensitive to the *order* of Alt being applied where
Unix is not.  Very, very strange ...

Tim Daneliuk     tundra at
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