[Tkinter-discuss] Re: Modal dialog behavior

[Michael Lange]

Martin, Jeff, Russell,

thanks for the replies,

> Could you share a small snippet of code that exhibits this behavior?  I
> use XFCE4 by default but can test with at least GNOME (I think I still
> have KDE on an older machine somewhere...)  I also have a couple of 
> version of Tk installed so we can at least narrow it down

A minimal code example that shows this behavior:

###############################
#!/usr/bin/env python
from Tkinter import *

class ModalDialog(Toplevel):
    def __init__(self, master=None, **kw):
        Toplevel.__init__(self, master, **kw)
        self.withdraw()
        
    def show(self):
        self.deiconify()
        self.transient(self.master)
        self.grab_set()

def main():
    root = Tk()
    top = ModalDialog(root)
    b = Button(root, text='Show', command=lambda:root.after(3000, top.show))
    b.pack()
    root.mainloop()

if __name__ == '__main__':
    main()
#################################

> Several things you can try:
> - Update to the current Tk (8.4.9). (You could search the tk bug 
> database first.)
> - Roll your own dialog box. How are you creating it anyway? 
> tkMessageBox? There are some "interesting" differences between Tkinter's 
> dialog boxes and the code suggested in Welch's "Practical Programming in 
> Tcl and Tk". I don't remember the details at the moment, but after 
> running into nasty problems with tkSimpleDialog.askfloat I ended up 
> writing my own dialog boxes*, mostly following Welch but with a few 
> changes that proved desirable for MacOS X aqua.
> 

I use Pmw.Dialog.activate() for modal dialogs. Unfortunately updating Tk is not much of
an option, because I want it to work with any Tk >= 8.3.3 .
Maybe the quick workaround to make the one dialog in my program where this is likely to
happen non-modal will be the best for now.

Thanks and best regards

Michael