private void accel_edited_cb (Gtk.CellRendererAccel cell, string path_string, uint keyval, Gdk.ModifierType mask, uint hardware_keycode)
{
    var path = new Gtk.TreePath.from_string (path_string);
    if (path == null)
        return;

    stdout.printf("%s\n", path_string);

    Gtk.TreeIter iter;
    if (!liststore[0].get_iter (out iter, path))
        return;

    string? key = null;
    liststore[0].get (iter, 0, out key);
    if (key == null)
        return;

    liststore[0].set (iter, 2, keyval);
    worm_settings[0].set_int (key, (int) keyval);
}