UIPrintInteractionControllerDelegate protocol is implemented by the delegate of the
UIPrintInteractionController shared instance to perform a number of optional tasks.
- iOS 4.2+
If the application has special requirements for content sizes, it can implement
printInteractionController(_:choosePaper:) to return a
UIPrintPaper object encapsulating the page size and the printing area to use for a print job. If you want more control of the presentation of the printing options, the delegate can return a view controller that owns the printing-options view in an implementation of
printInteractionControllerParentViewController(_:). The delegate can also implement methods that are invoked when the printing user interface is presented and when it is dismissed, and when the print job begins and ends.