[Tkinter-discuss] Syntactic problems

[Francisco Gracia]

I am exploring the possibilities of using *Tkinter* for a serious
application mainly devoted to the handling of pure text.

As en exercise I have tried to rewrite in *Python* an interesting example
that is unusually included in the manual page of *Tk* for the *font*
component (*Tcl8.5.7/Tk8.5.7 Documentation > TkCmd > font > example*); this
code works fine under *tclsh* and *wish*. What is does is getting a list of
the font names available in the machine in which it is running and
displaying nicely each of its items with a sample of the corresponding
font.

I have performed most of my purpose and my *Python* script works. Along the
way have learned a lot about *Tkinter/Tk/Tcl*, which was also a desired
goal of the exercise. But the script does not work completely well, as I
have also hit against an obstacle that I do not know how to overcome and
seems to be rather deep. It is the following:

Some of the names of the font families returned by the operating system (be
it Windows or Linux) are composed of two or more words (like *Times New
Roman CE*). Now these multiword arguments are not easily accepted by
*Tcl/Tk*, especially if they are referenced by some variable, so that for
instance tags cannot be reconfigured this way in order to apply such fonts;
or the size of sentences using them cannot be measured, two operations that
are essential for the procedure.

I have learned that this is a real and inherent difficulty with *Tcl*
(Harrison and McLennan, *Effective Tcl/Tk programming*: 34, 66); this is
why the original code uses such a strange syntax like

    .t tag configure f[incr count] -font [list $family 10]

The function *list* of *Tcl* seems to be mainly dedicated to solve this odd
problem with the dereferencing of multiword contents of variables (*family*
in this case, which holds the name of the font). But apparently this does
not work when *Tcl/Tk* are finally moved by *Tkinter* during the execution
of the script or at least I have been unable to find a way to make it work
in due form.

Which does not mean much, as I am not a programmer or, at most, I am a very
unseasoned one. Can somebody who has had the same problem and solved it
succesfully from *Tkinter* offer me (and perhaps us) his insight and
describe the essentials of how to do it?

Many thanks in advance!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/tkinter-discuss/attachments/20111202/66481922/attachment.html>