NSPrint protocol declares two methods that the
NSPrint class uses to get information from a printing accessory controller.
- macOS 10.5+
A printing accessory controller manages a custom print panel accessory view and used to coordinate print settings. If you are implementing a custom printing accessory view, your controller must support this protocol. Implementation of only one method in the protocol is actually required. The other method is considered optional and is used to support the print panel’s built-in preview facilities.