[Idle-dev] [ idlefork-Bugs-661324 ] Does not play well with Tkinter when on-quit handler invoked

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Bugs item #661324, was opened at 2003-01-02 21:58
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https://sourceforge.net/tracker/?func=detail&atid=109579&aid=661324&group_id=9579

Category: None
Group: None
Status: Open
Resolution: Accepted
Priority: 5
Submitted By: Chui Tey (teyc)
Assigned to: Nobody/Anonymous (nobody)
Summary: Does not play well with Tkinter when on-quit handler invoked

Initial Comment:
The following program:

import Tkinter
import sys

root = Tkinter.Tk()

console = Tkinter.Button(root, text='Done', 
command=root.quit)
console.pack()

root.mainloop()

locks up the running program if "Done" is pressed. The 
program stops locking when the Shell window is closed.

I observed this behaviour on Windows 2000, running 
ASPN Python 2.2.

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Comment By: David Harris (edcdave)
Date: 2003-03-17 18:07

Message:
Logged In: YES 
user_id=72287

I have tried several work-arounds and have come up with 
a quit technique which always works. Unfortunately, I 
can't figure out how to change IDLEfork to accomplish the 
necessary action.

The problem is that quit() (a member of the Misc class) 
goes for the jugular and tries to kill the top-top-level 
widget - the Tk() window opened by IDLE.

I found that walking the container chain backwards and 
destroying the first 'Tk' widget works, even it Tk() is not 
explicitly invoked by the application (that is, 
master=None). Here's an example:

def quit(self): # where self is a Tk widget or an instance
                      # object with a widget attribute
    parent = self
    while parent.winfo_class() != 'Tk':
        if parent.master == None:
            break;
        parent = parent.master
    else:
        parent.destroy()

The fact that this works indicates to me that Misc quit() is 
ignoring the toplevel window for the application and 
zapping IDLE's toplevel window instead.


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Comment By: David Harris (edcdave)
Date: 2003-03-01 02:18

Message:
Logged In: YES 
user_id=72287

The same behavior occurs when the command is "sys.exit".

Since the 'Close Window' widget works correctly, I looked at 
the Tkinter source to learn what was different. But I didn't go 
very far before I encountered some example code in 
Tkinter.py which uses tk.destroy as the command (where 
tk=Tk()).

Once I change to "destroy", the given code exits correctly, 
erasing the window.

Windows XP. IdleFork 0.92a. Python 2.2.2

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Comment By: Kurt B. Kaiser (kbk)
Date: 2003-01-03 17:51

Message:
Logged In: YES 
user_id=149084

Confirmed on IDLEfork/Linux.  Code can be Run again, though,
don't need to close shell.   Is that true for Windows?

Same program crashes Python IDLE on second button press,
something about a Tk callback error.  Probably some kind of
self abuse issue?

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You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=109579&aid=661324&group_id=9579