Example: Statusbar

public class Application : Gtk.Window {
public Application () {
// Prepare Gtk.Window:
this.title = "My Gtk.Statusbar";
this.window_position = Gtk.WindowPosition.CENTER;
this.destroy.connect (Gtk.main_quit);
this.set_default_size (350, 70);

// A Box:
Gtk.Box box = new Gtk.Box (Gtk.Orientation.VERTICAL, 0);
this.add (box);

// The Statusbar:
Gtk.Statusbar bar = new Gtk.Statusbar ();
box.pack_start (bar, false, false, 0);

uint context_id = bar.get_context_id ("example");
bar.push (context_id, "Waiting for response ...");

// A Button:
Gtk.Button button = new Gtk.Button.with_label ("Update");
box.pack_start (button, false, false, 0);

button.clicked.connect (() => {
bar.push (context_id, "Waiting for more response ...");
});
}

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

Application app = new Application ();
app.show_all ();
Gtk.main ();
return 0;
}
}

 valac --pkg gtk+-3.0 Gtk.Statusbar.vala

See: