5a-Fun-with-labels.pl

#! /usr/bin/perl

use strict;
use warnings;
use diagnostics;
use feature ':5.14';
use Gtk3 '-init';

use Glib qw/TRUE FALSE/;

#### DECLARATIONS

my $window = Gtk3::Window->new('toplevel');
$window->set_title("My Title");
$window->set_position("mouse");
$window->set_default_size(400, 50);
$window->set_border_width(20);
$window->signal_connect (delete_event => \&quit_function);

my $button1 = Gtk3::Button->new("Twist");
$button1->signal_connect (clicked => \&say_something, "twist");

my $button2 = Gtk3::Button->new("red");
$button2->signal_connect (clicked => \&say_something, "red");

my $button3 = Gtk3::Button->new("weird");
$button3->signal_connect (clicked => \&say_something, "weird");

my $hbox = Gtk3::Box->new("horizontal", 5);
$hbox->set_homogeneous (TRUE);
$hbox->pack_start($button1, TRUE, TRUE, 0);
$hbox->pack_start($button2, TRUE, TRUE, 0);
$hbox->pack_start($button3, TRUE, TRUE, 0);

my $vbox = Gtk3::Box->new("vertical", 5);
$vbox->add($hbox);

my $label = Gtk3::Label->new("Am I connected?");
$vbox->add($label);

$window->add($vbox);
$window->show_all;

#### FUNCTIONS

sub quit_function {
	say "Exiting Gtk3";
	Gtk3->main_quit;
	return FALSE;
}

sub say_something {
    my ($button, $userdata) = @_;
    if ($userdata eq "twist") {
        my $angle = $label->get_angle;
        $label->set_angle( $angle - 30 );
    } elsif ($userdata eq "red") {
        $label->set_markup('<span foreground="red"><i>Red and connected</i></span>');
    } elsif ($userdata eq "weird") {
        $label->set_markup('<span foreground="cyan" background="yellow" size="x-large"><b>Weird</b></span>');
    }
	return FALSE;
}

Gtk3->main;