+ number_label.set_text ("-");
+ number_label.set_no_show_all ();
+ number_label.set_name ("tracknumber label");
+ number_label.set_fixed_colors (0x80808080, 0x80808080);
+ number_label.set_elements (ArdourButton::Element(ArdourButton::Body | ArdourButton::Text));
+ number_label.set_alignment (.5, .5);
+ top_event_box.add (number_label);
+