private bool on_draw () {

            // empty container
            int available_size = get_available_size ();

            int i = 0;
            foreach (Event e in list) {
                GLib.List<Gtk.Widget> children = get_children();

                if (i < available_size) {
                    if (children.find(e) == null)
                        pack_start (e, false, false, 0);

                    e.show ();
                } else {
                    //if (children.find((Gtk.Widget) e) != null)
                    //    e.hide ();
                }

                i++;
            }

            return true;
        }