Push to Make (Single Pole) Button running a loop

[Jon Todd]

Happy holidays all!

I'm developing an application and, as a relative newbie to Python, have come
across a stumbling block with Tkinter.

I'd like to have a button that when pressed executes a loop (this could be a
thread) and then stops execution when it's released (Push to Make - Single
Pole in electronics terms).

I've tried the regular way of associating the procedure with a callback and
tried using <Button-1and <ButtonRelease-1bindings but am getting nowhere
fast (in the latter case the button release event seems to occur anyhows).

So my question is: Is there a neat way of doing this? And would it
necessarily involve creating a custom widget?

....

Also, while I'm here, what's the state of play regarding non-ASCII in
Tkinter widgets. I've been trying to get our currency symbol, £, to display
but didn't have much luck even playing with the coding: settings.

TIA

jon

[Hendrik van Rooyen]

"Jon Todd" <jo...en.co.ukwrote:

>I'd like to have a button that when pressed executes a loop (this could be a
thread) and then stops execution when it's released (Push to Make - Single
Pole in electronics terms).

I've tried the regular way of associating the procedure with a callback and
tried using <Button-1and <ButtonRelease-1bindings but am getting nowhere
fast (in the latter case the button release event seems to occur anyhows).

You are a bit stymied :

Afaik, Button needs the click on the button, leaving it depressed,
while ButtonRelease needs a click on the button, and the release can be anywhere
for drag and drop implementation. So it is possible to call two routines with
one
click and release.

But there is another hassle - you would have to code the loop as a separate
thread,
started by the first, while the second routine sets some variable that is
checked by
the loop to kill itself, as the GUI will not be responsive until the first
command
returns, because the command "captures" the main loop...

HTH - Hendrik