[sane-devel] A possible way to extend SANE API

[stef]

Le jeudi 18 juin 2009 11:06:46 Alessandro Zummo, vous avez écrit :
> On Thu, 18 Jun 2009 10:28:56 +0200
>
> Julien BLACHE <jb at jblache.org> wrote:
> > >  there are buggy scanners that do not return a warming up condition
> > > unless you actually start to scan.
> >
> > And scanners like the Epson Perfection 2480 and friends that tells you
> > it needs 23 seconds for warmup, then another 8 seconds.
>
>  I suggest we either create a generic retry return code or
>  we start making them a bit field, but that would add complexity.

	Hello,

	in fact, I am thinking that the would be 'sane_prepare_to_scan()' function 
would have to be called before each scan(before each call at sane_start). And 
it has to be called until it returns SANE_STATUS_GOOD and not 
SANE_PREPARATION_IN_PROGRESS. A frontend would have the choice to either wait 
the maximum time or poll it. The maximum wait time could be re-evaluated at 
each call by the backend.
	For scanners that don't know they need warming until they start a scan, would 
it be possible to start a 'internal' scan to trigger this ?

Regards,
	Stef