Tcl::Tk is an alternative binding to Tcl/Tk from Perl (as opposed to Perl/Tk). It uses Tcl in the bridge (which Perl/Tk does not). These are the Tcl [L1 ] and Tcl::Tk [L2 ] modules for Perl. Make sure you get the latest.
It has advantages over the traditional Perl/Tk in using less memory and being faster, as well as being more portable and flexible (for example, for use on Windows/CE). It gains this by linking directly against Tcl using a bridge that has deep understanding of Tcl_Objs and PerlSVs. It has a slightly varied interface, but there is a rough Perl/Tk compatability layer (about 80% compatability). It would be nice to see another module layered on top that provides near 100% Perl/Tk compability while maintaining the efficient lower layer that ties tightly to Tcl.
VK: Other advantages of Tcl, Tcl::Tk perl modules over Perl/Tk are briefly listed at perl's discussion site [L3 ]:
$interpreter->Eval('pure-tcl-code-to-create-and-manipulate-widgets');or use perlTk syntax
my $btn=$frame->Button(-text=>'Ok',-command=>sub{print 'ok'})->pack;Disadvantage and major compat issue over Perl/Tk is lack of documented way for creating of pure-perl widgets. This is currently work in progress. It is all technically possible, just needs to be done. Since Tcl::Tk is open to the world of Tcl/Tk widget sets (BLT, BWidgets, Tix, tile, iwidgets, vu, Tktable, ...), developers of new (from scratch) apps may find it easier to use these, but compat for older apps should remain a consideration.
an example of pure-perl widget based on mkWidgets package:
use Tcl::Tk;
my $int = new Tcl::Tk;
my $mw = $int->mainwindow;
#
# make pure-perl widget
#
# 1. bring mkWidgets package, it provides megawidgets (among others are snit, Tix, BWidget, IWidgets)
$int->pkg_require('mkWidgets');
# 2. create metawidget
# 2.1 metawidget itself
$int->metawidgetCreate('LabEntry2', sub {
#print STDERR "init proc: instantiation of a metawidget; create internal widgets\n";
my $this = $int->widget($int->GetVar('this'));
my ($var1,$var2);
my ($rvar1,$rvar2) = \($var1,$var2);
my $lab1 = $this->Label(-text=>'lab1')->grid(-column=>0,-row=>0,-sticky=>'e');
my $ed1 = $this->Entry(-textvariable=>\$var1)->grid(-column=>1,-row=>0,-sticky=>'w');
my $lab2 = $this->Label(-text=>'lab2 [][][]')->grid(-column=>0,-row=>1,-sticky=>'e');
my $ed2 = $this->Entry(-textvariable=>\$var2)->grid(-column=>1,-row=>1,-sticky=>'w');
my $btn = $this->Button(-text=>'frustrate',-command=>sub{$this->frustrate})
->grid(-column=>0,-row=>2,-sticky=>'we',-columnspan=>2);
$this->widget_data->{w} = [$lab1,$ed1,$lab2,$ed2,$btn,$rvar1,$rvar2];
}, sub {
print STDERR "exit proc: destruction of a metawidget; delete internal widgets\n";
my $this = $int->widget($int->GetVar('this'));
# do I need deleting child widgets? those are deleted automatically
});
# 2.2 some of its methods/options
$int->metawidgetCommand('LabEntry2', frustrate=> sub {
my $this = $int->widget($int->GetVar('this'));
# frustrate method of our megawidget swaps two entry subwidgets, so user will be frustrated
# TODO
print STDERR "frustrate\n";
});
$int->metawidgetOption('LabEntry2', -textvariable1=> sub {
my $this = $int->widget($int->GetVar('this'));
# TODO
print STDERR "frustrate\n";
});
# 3. now Tcl/Tk has our megawidget; bring it to Perl
$mw->Declare('LabEntry2','labentry2');
# megawidget creation completed. now use it
my $mywid = $mw->LabEntry2->pack;
$int->MainLoop;Code above will be cleaned up and commented later, and also demonstrations of pure-perl widgets based on other Tcl approaches will be added.