#!/usr/bin/perl
use warnings;
use strict;

use Tk;
use Tk::ROText;

my $mw = 'MainWindow'->new(-title => 'Tagging');

$mw->Label(-text => 'Here, the tags are being created:')->pack;
my $rotext = $mw->ROText->pack;
$mw->Label(-text => 'Try typing here, including the letter "s":')->pac
+k;
my $text = $mw->Text(-width => 20, -height => 3)->pack;
$mw->Entry(-text => 'Click here to change focus.', -state => 'readonly
+')->pack;
my $label = $mw->Label(-textvariable => \ my $l)->pack;

my $max = 1000;
my ($i, $repeat, $stop);
$repeat = $mw->repeat(10, sub {
    return if $stop;

    ++$i;
    $rotext->insert('end', $i, "T$i");
    $l = "$i/$max tags added. Press 's' to stop.";
    $repeat->cancel if $i == $max;
});

sub stop {
    $stop = ! $stop;
    $l =~ s/stop/start/;
}

$mw->bind('<s>', \&stop);
$text->bind('<FocusIn>',  sub { $mw->bind('<s>', "") });
$text->bind('<FocusOut>', sub { $mw->bind('<s>', \&stop) });

MainLoop();
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Update: Fixed the problem with "stop" not being updated.