Tkinter bug in Entry widgets on OS X

[Arnaud Delobelle]

On 1 September 2012 11:30, Peter Otten <__peter__ at web.de> wrote:
> Arnaud Delobelle wrote:
>> It would be good if I could intercept the key press event and cancel its
>> action on the Entry widget.  It's easy to intercept the key event, but I
>> haven't found out how to prevent the funny characters from being inserted
>> into the Entry widget input area.
>
> Untested as I have no Mac:
>
> import Tkinter as tk
>
> def suppress(event):
>     if event.keycode in {111, 116}:
>         print "ignoring", event.keycode
>         return "break"
>     print event.keycode, "accepted"
>
> root = tk.Tk()
> entry = tk.Entry(root)
> entry.bind("<Key>", suppress)
> entry.pack()
>
> root.mainloop()

This works fine!

return "break" is the piece of knowledge that I was missing. Thanks a
lot!  In fact I lied a bit in my original message - I do use the UP
and DOWN arrows on one Entry widget for navigating its command
history. To do this I was binding the "<Up>" and "<Down>" events to a
function, which simply has to return "break" to work around the bug.
On other Entry widgets, I just bind "<Up>" and "<Down>" to a suppress
function which simply returns "break".

>> I've struggled to find good tkinter
>> docs on the web.
>
> For my (basic) needs I keep coming back to
>
> http://infohost.nmt.edu/tcc/help/pubs/tkinter/

Thanks for the link.  I was using the docs on effbot which are nice
but probably incomplete (and old).

I guess I should flag up this bug but I don't even know if it's a
Python or Tk problem and have little time or expertise to investigate.

-- 
Arnaud