On Oct 28, 2010, at 3:37 , Jeff Hobbs wrote:
> On 2010-10-22, at 10:01 AM, Lindley, Robert A wrote:
>> I would like to use the tktable widget, but can't find any information on
>> how to pass something as the -variable option and be able to display and
>> retrieve data.
>>
>> use Tkx;
>> Tkx::package_require("Tktable");
>>
>> my $mw = Tkx::widget->new(".");
>> my $t = $mw->new_table(
>> -rows => 5,
>> -cols => 3,
>> );
>> $t->g_pack;
>>
>> Tkx::MainLoop()
>>
>> I found the above in the ActiveState documentation. It works as expected.
>>
>> All attempts to display or retrieve data have failed.
>
> So in working with Bob to address this, I found that there is a key missing
> feature in Tkx to support the final solution - obtaining the $interp used by
> Tkx.
>
> My first point was that the table by default needs a data source. The easiest
> is to use '-cache => 1' to say cache data in memory. To tie it to a hash, you
> need to use tie and reference the tied name in Tcl (.e.g -variable =>
> 'myarray'). It turns out the docs for Tcl.pm are incorrect in not quoting
> Tcl::Var, but it would look like this:
>
> tie %hash, 'Tcl::Var', $interp, "myarray";
>
> The real problem though is how do you get $interp from Tkx? It looks like
> you don't. It's a 'my' var in Tkx::i namespace, and the rest of the package
> handily abstracts everything so neatly that you don't need access to $interp.
> EXCEPT in this one case. I patched Tkx to have
>
> sub interp { return $interp; }
>
> in the Tkx::i namespace, which would allow:
>
> tie %hash, 'Tcl::Var', Tkx::i::interp(), "myarray";
>
> and checked that this does work with the attached sources. The question is,
> is this the correct answer? Should Tkx have a different redirect for 'tie',
> or should there be another way to get the $interp reference that Tkx uses?
>
> Gisle - any thoughts on this?
The $interp is hidden because I simply did not want to expose any of the Tcl.pm
interface. I wanted Tkx to stand on its own, be easy to grok, and be
documented without reference to Tcl.pm. That would also allow a potential
future development where Tkx embeds libtcl directly instead of adaping the
Tcl.pm interfaces and its quirks. This isn't likely to happen any time soon,
so I don't mind adding a (undocumented) Tkx::i::interp() function for the cases
where you need direct access.
For this specific problem I think we should just make passing of a hash
reference to a Tcl command work the same way it works to pass a scalar
reference. It should then be possible to just use:
my %hash = ( # data to display
'1,1' => 'Goodby',
'2,2' => 'cruel',
'3,3' => 'world',
);
my $t = $mw->new_table(
-rows => 5,
-cols => 3,
-variable => \%hash,
);
I'll play around a bit to figure if I can make that work easily.
Regards,
Gisle
