Ejemplo boton P/G3

#!/usr/bin/env perl
#===============================================================================
#
#         FILE: ejemplo.pl
#
#        USAGE: ./ejemplo.pl
#
#  DESCRIPTION: :
#
#      OPTIONS: ---
# REQUIREMENTS: ---
#         BUGS: ---
#        NOTES: ---
#       AUTHOR: YOUR NAME (),
# ORGANIZATION:
#      VERSION: 1.0
#      CREATED: 27/11/12 16:58:52
#     REVISION: ---
#===============================================================================

use strict;
use warnings;
use utf8;

use Gtk3 '-init';
use Glib 'TRUE', 'FALSE';

my $ventana = Gtk3::Window->new('toplevel');
$ventana->set_title('Ejemplo');
$ventana->set_default_size(200, 200);$ventana->set_border_width(5);
$ventana->signal_connect( destroy  => sub { Gtk3->main_quit } );

my $hbox = Gtk3::Box->new( 'horizontal', 10 );

my $botones = Gtk3::Notebook->new();
$botones->set_show_tabs(FALSE);
$botones->set_show_border(FALSE);
$hbox->pack_start( $botones, TRUE, TRUE, 0 );

my $boton1 = Gtk3::ToolButton->new_from_stock('gtk-media-play');
$boton1->signal_connect( clicked => \&show_stop );
$botones->append_page($boton1);


my $boton2 = Gtk3::ToolButton->new_from_stock('gtk-media-stop');
$boton2->signal_connect( clicked => \&show_play );
$botones->append_page($boton2);

my $label = Gtk3::Label->new("Perl Gtk3");
my $label2 = Gtk3::Label->new("");

my $vbox = Gtk3::Box->new( 'vertical', 5 );
$vbox->pack_start( $label, FALSE, FALSE, 10 );
$vbox->pack_start( $hbox, FALSE, FALSE, 10 );
$vbox->pack_start( $label2, FALSE, FALSE, 0 );
$vbox->set_border_width(5);

$ventana->add($vbox);

$ventana->show_all;

Gtk3->main();

sub show_play {
    $botones->set_current_page(0);
   $label2->set_markup("Play");
}

sub show_stop {
    $botones->set_current_page(1);
    $label2->set_markup("Stop");
}