Re: Printing with xlib & art backend

[Fred Kiefer]

On 06.07.2013 00:57, Riccardo Mottola wrote:
> Hi,
>
> I think this has mostly to do with Eric's optimisations about 2 years ago.
> Riccardo Mottola wrote:
> > > Printing error: <NSException: 0x84762e4>
> > > NAME:NSInvalidArgumentException
> > > REASON:[GSStreamContext-GSDefineGState] not implemented INFO:(null)
> GSStreamContexts does not implement GSDefineGState explicitely, throwing
> an exception.
>
> During Eric's refactor, a lot of code was moved from NSImage to
> NSImageRep, but also PS operation were substituted with DPS operation,
> which do require gState though.
>
> Thus my educated guess is that printing images is broken since that time
> except on cairo
>
> I had the idea of using supportsDrawingGState to skip, but it is
> incorrect and it will break, as then DPSComposite doesn't work.
>
> Ideas?

I most admit that I don't fully understand the issue here. We never 
supported GSDefineGState in GSStreamContext and this would have always 
resulted in an exception when called. Which is one of the known 
limitation of that code and a reason why we have to drop support for all 
these backends in the near future.

Eric's change should, as far as I see only call GSDefineGState if the 
context has supportsDrawingGState return YES. Which should only be true 
for the cairo and the windows backend. I don't see how you should ever 
end up there for the art or xlib backend. Could you please provide me 
with a back trace of the stack, when this happens?