onPageReordered  
  fun onPageReordered(connectFlags: <Error class: unknown class> = ConnectFlags(0u), handler: (child: Widget, <Error class: unknown class>) -> Unit): <Error class: unknown class>(source)
the ::page-reordered signal is emitted in the notebook right after a page has been reordered.
Parameters
connectFlags 
a combination of ConnectFlags
handler
the Callback to connect. Params: child the child GtkWidget affected; pageNum the new page number for @child