using Gtk;

static int main (string[] args) {
    Gtk.init (ref args);

    var window = new Window (WindowType.TOPLEVEL);
    window.title = "Aprendendo Vala no Viva o Linux";
    window.set_default_size (300, 50);
    window.position = WindowPosition.CENTER;
    window.destroy += Gtk.main_quit;

    var button = new Button.with_label ("Clica aqui!");
    button.clicked += (source) => {
        source.label = "Obrigado por clicar!";
    };

    window.add (button);
    window.show_all ();

    Gtk.main ();
    return 0;
}