Question

Specs:
Python2.7.1
Tkinter (Tk version 8.5)
Windows7
IDLE 2.7.1

I’m coding a program that ‘spawns’ two windows, withdraws both, destroys one and then deiconifies the other (which then enters a mainloop).
This arrangement is interfering with a Checkbutton on the remaining window.

eg:

temp = Tk()
temp.withdraw()

root = Tk()
root.withdraw()
temp.destroy()

root.mainloop()

(It seems unusual, but it is set up this way so that the ‘temp’ window will display the problems that arose, during building of the root window).

However,
it seems that as soon as a single program deals with two Tkinter windows,
functionality of a Checkbutton (in root) goes out the window.

def ClickAButton():
    print Toggle.get()
Toggle = IntVar()
Checkbutton(root, text = "Me is broke", variable = Toggle).pack()
ClickAButton

Toggle.get() should return a 1 if the Checkbutton is ticked, otherwise a 0.
However, since adding the new window, Toggle.get always returns a 0.

(I’ve tried reformatting code {this brings up strange erros of it’s own},
renaming variables, etc.
The Checkbutton works just fine without the ‘temp’ window.

The ‘temp’ window is destroyed before the Checkbutton is even assigned, packed,
or ‘root’ even enters a mainloop!)

Entire eg:

temp = Tk()
temp.withdraw()
root = Tk()
root.withdraw()
if 'certain condition':
    root.destroy()
    temp.deiconify()
    temp.mainloop()
else:
    temp.destroy() 
    Toggle = IntVar()
    Checkbutton(root, text = "Why I only return 0?", variable = Toggle).pack()
    root.deiconify()
    root.mainloop()

For some reason,
the Checkbutton is always returns 0, even when checked.
I suspect it’s a multi-threading issue with Tkinter.

Is there anything at all I can do here?
(The actual coding is HUGE. I’m not eager to switch it all to another GUI module)
😐

Greatly appreciated!

(I only started programming the start of this year.
Please forgive me if I’ve made some horribly noobish mistake!)

Answer 1

Tkinter isn’t designed to have two root windows. I’m amazed your code works at all. This has nothing to do with multi-threading — Tkinter is single threaded and you don’t appear to be creating any new threads (though if you are, that might contribute to the problem)/

You need to create a single root window with a single mainloop. If you need another window, create a Toplevel window — that’s precisely what that widget is for.