GtkPrintDialog: support manual dual-side printing
One of the most important features that GtkPrintDialog is currently missing is support for manual dual-side printing. This usually works as follows:
- even or odd pages are printed only, in single-side mode
- a warning dialog to insert the pages in reverse order (in a position which can only partly vary according to the printer model) is shown. all other queued tasks are paused in the meanwhile
- when confirmation is given, the other half of pages is printed, and the job is marked as terminated
This feature would be extremely useful (and even eco-friendly!) to have in my opinion, so it would be nice to consider implementing it. I know it is somewhat "oblique" through the stack (possibly not only affecting Gtk), but this seemed like the best place to open it.
Random "relevant art", from my Epson printer software: