#!/usr/bin/env perl

use strict;
use warnings;

use Tk;

my $mw = MainWindow::->new();

my $mb = $mw->Menubutton(-text => 'Popup');
my $menu = $mb->menu();
$mb->configure(-menu => $menu);
$mb->pack();

$mw->Button(
    -text => 'Add menu item',
    -command => sub {
        $mb->command(-label => 'A', -command => sub { 1 })
    },
)->pack();

MainLoop;