#!/usr/bin/perl -w
use strict;
use Tk;

my $counter = 0;
my $test = new Test();
my $mw = tkinit();

print $test->counter();

my $button1 = $mw->Button(-textvariable => \$counter)->pack();
my $button2 = $mw->Button(-textvariable => $test->counter()  )->pack();

$mw->repeat(100 => sub { fetch_data($test) });
MainLoop;

sub fetch_data {
  my $obj = shift;

  $counter++;
  $obj->counter( $obj->counter()+1 );
}


package Test;
sub new {
        bless {counter => 0}, shift;
}

sub counter {
  $_[1] ? $_[0]->{'counter'} = $_[1] : \$_[0]->{'counter'};
}
1;