[Development] QtPrintSupport - Platform Support

[John Layt]

Hi,

While starting to review the current state of QtPrintSupport for Beta 1 and 
one thing I've immediately noticed is an inconsistency in the platform 
implementations as to which plugins have which classes where.

OSX:

src/plugins/platforms/cocoa    - QMacPrintEngine
                               - QCoreGraphicsPaintEngine
                               - QCocoaPrinterSupport
src/plugins/printsupport/cocoa - QCocoaPrinterSupportPlugin

Windows:

src/plugins/platforms/windows  - none
src/plugins/printsupport/cocoa - QWindowsPrinterSupportPlugin
                               - QWindowsPrinterSupport
src/printsupport/kernel        - QWin32PrintEngine
                               - QAlphaPaintEngine


Linux:

src/platformsupport/genericunix - QGenericUnixPrinterSupport
src/printsupport/kernel         - QPdfPrintEngine
                                - QCUPSSupport
                                - qprinterinfo_unix

Can anyone explain why we have these differences, or any objections why we 
shouldn't move them around to be consistent:

src/plugins/platforms/xxx    - QxxxPaintEngine
src/plugins/printsupport/xxx - QxxxPrinterSupportPlugin
                             - QxxxPrinterSupport
                             - QxxxPrintEngine

We could then move all the CUPS specific stuff into 
src/plugins/printsupport/cups

I'm also concerned about QT_NO_CUPS and QT_NO_LPR.  I'd like to make it more 
explicit that we only support Linux printing using CUPS and remove all 
references to LPR and QT_NO_LPR altogether (including all the 
AIX/HPUX/Solaris/IRIX code still left!).  QT_NO_CUPS would then also be 
redundant as we have QT_NO_PRINTER already.

Thoughts?

John.

P.S. Please also note that the auto tests are seriously broken and shouldn't 
be relied upon when making changes. I'm working on sorting this out.