observe_controllers

Returns a `GListModel` to track the [class@Gtk.

EventController]s of this.

Calling this function will enable extra internal bookkeeping to track controllers and emit signals on the returned listmodel. It may slow down operations a lot.

Applications should try hard to avoid calling this function because of the slowdowns.

Parameters:

this	a `GtkWidget`

Returns:

a `GListModel` tracking this's controllers