_session->engine().PortRegisteredOrUnregistered.connect (_session_connections, invalidator (*this), boost::bind (&PortMatrix::setup_global_ports, this), gui_context());
/* watch for route order keys changing, which changes the order of things in our global ports list(s) */
_session->engine().PortRegisteredOrUnregistered.connect (_session_connections, invalidator (*this), boost::bind (&PortMatrix::setup_global_ports, this), gui_context());
/* watch for route order keys changing, which changes the order of things in our global ports list(s) */