#!/usr/bin/perl

use warnings;
use strict;
use Tk;

my $mw = MainWindow->new;

my $c = $mw->Scrolled(
        qw/Canvas -width 400 -height 400 -relief sunken
        -bg white -borderwidth 1 -scrollbars se -scrollregion/ => 
                [qw/0 0 1000 1000/])->pack;
                
$mw->bind($mw, '<MouseWheel>', 
        [sub { my $unit = $_[1] > 0 ? -1 : 1; $c->yviewScroll($unit => 'units'); }, Ev('D')]
);

MainLoop;