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

our $percent_done = 0;
our $stopped = 0;

my $mw = new MainWindow;

$mw->geometry('200x100+100+100');

my $progress = $mw->ProgressBar(
  -width => 40,
  -height => 20,
  -from => 0,
  -to => 100,
  -blocks => 50,
  -colors => [0, 'blue',30,'yellow',70,'orange'],
  -variable => \$percent_done
)->pack(-expand=>1, -fill=>'x');

my $buttonF = $mw->Frame->pack;

my $timer;

my $startB = $buttonF->Button(
  -text => 'start',
  -command => sub {
        $stopped = 0;
        $percent_done = 0;
      
      #restore original colors 
$progress->configure('-colors',[0, 'blue',30,'yellow',70,'orange'] );
               
               $mw->idletasks; # these commands
               $mw->update;    # don't seem to work
                               #but a window resize does
        $timer = $mw->repeat(50,
          sub{
              $percent_done++;
              $progress->update;
           
               if ($stopped) {
      #set red colors
     $progress->configure('-colors', [0, 'red',30,'red',70,'red'] );
               
               $mw->idletasks; # these commands
               $mw->update;    # don't seem to work
                               #but a window resize does
               
               
                $timer->cancel;
               }
             })        
     }
)->pack(-side => 'left');

my $stopB = $buttonF->Button(
  -text => "stop",
  -command => sub { $stopped = 1; }
 )->pack(-side => 'left');

MainLoop;