#!/usr/bin/perl
use Tk;
use strict;
package MyButton;

# see perldoc Tk::mega 

use base qw/Tk::Derived Tk::Button/;
Construct Tk::Widget 'MyButton';

sub ClassInit {
     my ($class, $mw) = @_;
     $class->SUPER::ClassInit($mw);
#    $mw->bind($class, '<Enter>', sub{print "Entered a MyButton\n"}); 
}

sub Populate {
     my ($self, $args) = @_;
     $self->SUPER::Populate($args);
     $self->bind('<Enter>', sub{print "Entered a MyButton\n"});
#    my (@bt) = $self->bindtags; 
#    $self->bindtags( [ @bt[ 1, 0, 2, 3 ] ] ); 
}

1;

package main;

my $mw = MainWindow->new;
$mw->Button(-text => 'NormalButton')->pack;
$mw->MyButton(-text => 'MyButton')->pack;

MainLoop;