Question

How can I simply disable a TkInter Listbox? It seems such a straightforward thing to do and possibly it is. In the simple example below, I’ve got a button which should toggle the state of the listbox from fully selectable to greyed and unselectable.

#!/usr/bin/python

from Tkinter import *

class MyDialog:
    def __init__(self, rootWin):
        self.rootWin_ = rootWin
        self.frame_ = Frame( self.rootWin_, borderwidth=10 )
        self.frame_.grid(row=0, column=0)
        self.listBox_ = Listbox( self.frame_, height=4, width=30, selectbackground='#000000' )
        self.listBox_.grid(row=0, column=0)
        self.lbEnabled_ = 1
        for item in [ 'Red', 'Orange', 'Yellow', 'Green', 'Blue', 'Indigo', 'Violet' ]:
            self.listBox_.insert(END, item)
        self.button_ = Button( self.frame_, text='Disable', command=self.onEnableDisable)
        self.button_.grid(row=1, column=0)

    def go(self):
        self.rootWin_.mainloop()

    def onEnableDisable(self):
        if self.lbEnabled_ == 1:
            self.button_.config( text='Enable' )
            # TODO enable the list box
            self.lbEnabled_ = 0
        else:
            self.button_.config( text='Disable' )
            # TODO disable the list box
            self.lbEnabled_ = 1

def main():
    myDlg = MyDialog(Tk())
    myDlg.go()

if __name__ == '__main__':
    main()

I’ve tried a few things including changing state:

self.listBox_.config( state = DISABLED )

The reference documentation I’ve found suggests you can set this with the state attribute:

state By default, a listbox is in the NORMAL state. To make the listbox unresponsive to mouse events, set this option to DISABLED.

However, if I try this, all I get is:

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python2.4/lib-tk/Tkinter.py", line 1345, in __call__
    return self.func(*args)
  File "./example.py", line 24, in onEnableDisable
    self.listBox_.config( state = DISABLED )
  File "/usr/lib/python2.4/lib-tk/Tkinter.py", line 1139, in configure
    return self._configure('configure', cnf, kw)
  File "/usr/lib/python2.4/lib-tk/Tkinter.py", line 1130, in _configure
    self.tk.call(_flatten((self._w, cmd)) + self._options(cnf))
TclError: unknown option "-state"

As you can see, I’m using a pretty old version (2.4) of python which probbaly won’t help, but I have no control over. Any ideas?

Answer 1

Your proposed code works for me (python 2.6, OS-X). It actually looks like Tkinter is doing the right thing from the traceback. Perhaps you’re also using an old version of Tcl/Tk which could also cause the problem you’re seeing. If you don’t have control over the python version, do you have control over the Tk version?