#!/usr/bin/perl
use strict;
use Tk;
use Tk::ProgressBar;

#dosn't leak

my $mw=MainWindow->new;
$mw->geometry('+100+100');

my $tframe = $mw->Frame->pack();

my $pro_on = 0;
my $count = 0;

my $label = $tframe->Label(
           -text => 'Show Progress',
          )->pack(-side => 'left', -padx => 5);


my $cb = $tframe->Checkbutton(
            -activebackground => "white",
            -variable => \$pro_on,             
            -command  => [ \&display_pro ]
          )->pack(-side => 'left');

my $bframe = $mw->Frame->pack();

my $pb = $bframe->ProgressBar(
   -height      => 0,
   -width       => 20,
   -length      => 100,
   -colors=>[0,'blue'],
   -blocks=>100,
   -variable => \$count,
   )->pack();

# need to pack then unpack them to get right window size
my @w = $bframe->packSlaves;
foreach (@w) { $_->packForget; }

MainLoop;

sub display_pro {
   print $pro_on,"\n";
    
   if($pro_on){
      $count  = 0;
      $bframe->pack();    
      $pb->pack();
#      $mw->packPropagate;
#      $mw->update;
      show_progress();
   }else{
   
     my @w = $bframe->packSlaves;
     foreach (@w) { $_->packForget; }
     $bframe->packForget;
   
   }
}

sub show_progress{
  my $timer;
  $timer = $mw->repeat(100,sub{
       $count++;
       $pb->value($count);
       $mw->update;
       if($count == 100){$timer->cancel}
     });
}
__END__