Gets the value of GTK_PRINT_SETTINGS_DUPLEX.
GTK_PRINT_SETTINGS_DUPLEX
gtkPrintSettingsGetDuplex(object)
object
a GtkPrintSettings
GtkPrintSettings
Since 2.10
[GtkPrintDuplex] whether to print the output in duplex.
GtkPrintDuplex
Derived by RGtkGen from GTK+ documentation