IPP> Re: [printing-cap] Capabilities API: Device Object [How about a M edia Object]

IPP> Re: [printing-cap] Capabilities API: Device Object [How about a M edia Object]

IPP> Re: [printing-cap] Capabilities API: Device Object [How about a M edia Object]

Michael Sweet mike at easysw.com
Fri Sep 27 08:41:37 EDT 2002


Hastings, Tom N wrote:
 > ...
 > The only problem left is what to return when the job context supplied
 > doesn't specify enough to return a single set of margins?  For
 > example, if the margins depend on the media size, but the job context
 > didn't have a media size.  Or as another example, suppose the margins

But the printer object has defaults for all printing attributes,
which are used when the job object doesn't override them...

 > depend on whether one-sided or two-sided printing is to be done, but
 > the job context doesn't supply the "sides" attribute.  How about just

Again, "sides" is defaulted.

However, in the case of many of the current HP inkjets with the
auto-duplexer option, the top and bottom margins are swapped for
the back page.  In CUPS we have a PPD attribute for this, but in
general I'd suspect the sane thing to do would be to report the
same top and bottom margin (the larger of the two for safety, and
the app/user can still try printing outside of those margins)

 > Comment on papiPrinterQuery: I assume that when the caller omits most
 > or all of the job context, that what is returned is more like all
 > possible things supported, rather than assuming the defaults for each
 > of the job context attributes.  That should be clarified (along with
 > the union versus intersection issue).

If we use constraints, then the query operation without job attrs
will list all possible values (+ the constraints); the addition of
job attrs will only narrow the query results.

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products                  mike at easysw.com
Printing Software for UNIX                       http://www.easysw.com




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