GObject.signal_override_class_closure

function signal_override_class_closure(signal_id: Number(guint), instance_type: GObject.Type, class_closure: Function): void {
    // Gjs wrapper for g_signal_override_class_closure()
}
  

Overrides the class closure (i.e. the default handler) for the given signal for emissions on instances of instance_type. instance_type must be derived from the type to which the signal belongs.

See GObject.signal_chain_from_overridden and GObject.signal_chain_from_overridden_handler for how to chain up to the parent class closure from inside the overridden one.