if (locked_film) {
_film_change_connection = locked_film->Change.connect (boost::bind (&HintsDialog::film_change, this, _1));
_film_content_change_connection = locked_film->ContentChange.connect (boost::bind (&HintsDialog::film_content_change, this, _1));
if (locked_film) {
_film_change_connection = locked_film->Change.connect (boost::bind (&HintsDialog::film_change, this, _1));
_film_content_change_connection = locked_film->ContentChange.connect (boost::bind (&HintsDialog::film_content_change, this, _1));