[Tkinter-discuss] Problem with 'cascade' and state=disabled (maybe)

Henry S. Thompson ht at inf.ed.ac.uk
Mon Feb 7 22:35:15 CET 2005

Jeff Epler <jepler at unpythonic.net> writes:

> Do you have a full program that demonstrates the problem?
> It's *likely* that str(w.entrycget(0, 'menu')) will return the menu's path
> as a string, in all cases.

Nope, that's precisely the bug.

> It's also possible that
>     import Tkinter
>     Tkinter.wantobjects = 0
> before creating any interpeter will get you a string instead.

Yes, that 'fixed' the problem.  But of course it had the side-effect
of causing other uses of entryget to _stop_ returning numbers and go
back to their old behaviour of returning strings.

> Tcl started as a typeless language:  everything is a string, but some
> strings can be interpreted as lists, as numbers, or as commands.  In
> later versions, Tcl gained an "object" representation, with a C type
> called TclObj* which could hold just a string, an efficient
> representation of numbers or lists, a pointer directly to a command,
> etc.
> With 'wantobjects = 1' (the default), a wrapper of a TclObject* can be
> returned from Tkinter calls, rather than a string.  In this case, you're
> getting the command object that corresponds to the menu widget, rather
> than the string naming the menu widget, or the Python object that wraps
> that particular menu widget.

So that seems like a bug, and whatever magic (in _tkinter.c ?)
negotiates return types should surely never let a raw cmdObject
surface into Python. . .

I will _try_ to produce a small test case, it may be difficult. . .

 Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
                     Half-time member of W3C Team
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