On 11-06-2019 09:59, Alex X wrote:

APaned.addOnMoveHandle((GtkScrollType, Paned p) { });

Is never called. Is there something I have to do to make this work?

According to the GTK documentation it is only called when the separator
is moved with a key binding.

This should probably do what you want:

APaned.addOnNotify((ParamSpec, ObjectG obj) {  }, "position");

You can cast obj to Paned if you need it.