GObject.signal_lookup

function signal_lookup(name: String, itype: GObject.Type): Number(guint) {
    // Gjs wrapper for g_signal_lookup()
}
  

Given the name of the signal and the type of object it connects to, gets the signal's identifying integer. Emitting the signal by number is somewhat faster than using the name each time.

Also tries the ancestors of the given type.

See GObject.signal_new for details on allowed signal names.