[sane-devel] Well-known options (was Re: API addition request)

[Olaf Meeuwissen]

"m. allan noah" <kitno455 at gmail.com> writes:

> Well, if we dont use params, our only choice with the current API is
> more well-known options. One advantage of moving maintained backends
> to a new package would be the possibility of regularizing/requiring
> such options...

 +1 on more well-known options
 +1 on regularising options
 -1 on requiring more options

Unless you pick your well-known options extremely carefully, requiring
them may put undue burden on backend implementers.  Anything beyond
requiring the currently well-known options in the standard would be
questionable at best.

As mentioned on the ICC thread, adding "tags" to options to indicate
what general area functionality they provide/affect seems like something
that deserves some thought.  Options could then indicate to frontends
that they affect colour and speed, for example.

The CommonPrintingDialog[1] is heading in that direction and want to use
the tags for grouping purposes and let users pick the set of tags (and
therefore options) that they care about.  This solves the problem where
users are completely overwhelmed by the myriad of available options in a
tabbed dialog where you can never find what you're looking for (hint:
the options is always on the last tab you check).

  [1] http://www.linuxfoundation.org/en/OpenPrinting/CommonPrintingDialog

The currently defined well-known options seem to be fairly well-defined
although I'm not so sure that the definition for preview mode is easy
to satisfy on the backend side in all situations.  With respect to the
resolution, it is not clear from whose point of view (user, frontend,
backend) this is defined (and who should be responsible for adjusting
the image data if the device doesn't support the resolution).

Hope this helps,
-- 
Olaf Meeuwissen, LPIC-2           FLOSS Engineer -- AVASYS Corporation
FSF Associate Member #1962               Help support software freedom
                 http://www.fsf.org/jf?referrer=1962