[Development] Plans for printing in 5.3 onwards

[Sorvig Morten]

On 30 Jan 2014, at 01:15, John Layt <jlayt at kde.org> wrote:
> 
> I've just pushed a 33 commit change set for this to Gerrit, my apologies to 
> the people I've tagged as reviewers :-)  Any one else interested, feel free to 
> jump in and help.
> 
> There's 4 main new classes:
> * QPageSize
> * QPageMargins
> * QPageLayout 
> * QPlatformPrintDevice, with backends for Windows, Mac and Cups
> 
> These are then used in a fairly major rewrite of the platform and PDF print 
> engines and QPrinter itself.  I've tested these changes using my limited set 
> of printers and some test painting code, but obviously I can't test for 
> everything, especially the wide variety of drivers and the dodgy data they may 
> return.  I'd appreciate if people could check out the last commit in the chain 
> [1] and see if it works OK with your printers and apps and report any problems 
> back here.

Thanks for the contribution! My initial impression is that it looks like a solid design and implementaiton. I’m not sure how to review it in detail - you are now the expert on Mac printing.

We know from our work with the new platform plugins for Qt 5 that a re-implementation of existing functionality is unlikely to be bug-for-bug compatible. I can’t really say what the state is for printing, but I would like to avoid a situation where 5.3 improves in some areas but regresses in others.

Have you considered keeping the current implementation side-by-side with the new one and adding an opt-in/opt-out mechanism for 5.3? This could then be accompanied with a blog post or other suitably public announcement that *now* is your chance to test and report bugs against the new printing implementation before the old one is removed.

As a reviewer I will at least be more comfortable giving a +2 if I know that the new code will be field tested before becoming the only print support in Qt.

Morten