The number of pages that will be printed.
Note that this value is set during print preparation phase (gtk.types.PrintStatus.Preparing), so this value should never be get before the data generation phase (gtk.types.PrintStatus.GeneratingData). You can connect to the signal@Gtk.PrintOperation::status-changed signal and call gtk.print_operation.PrintOperation.getNPagesToPrint when print status is gtk.types.PrintStatus.GeneratingData.
This is typically used to track the progress of print operation.
Get nPagesToPrint property.