Re: GSCUPS and GNUstep Printing

[Chad Hardin]

Using CUPS also expands the number of options available for a printing 
dialog box.


On Jun 11, 2004, at 2:47 AM, Pete French wrote:

> > So maybe this is more of an #ifdef #elif type thing....  Comments?  
> > How
> > do people feel about making CUPS the sole supported printing system on
> > UNIX machines?  If people really object to that, then there could be
> > three setups:  UNIX like it is now, UNIX with CUPS, and Windows.
>
> I dont thing that using CUPS as the solue UNIX interface is necessarily
> a good idea - the system should be portbale and thus need to talk
> to 'lp' and 'lpr' based systems as well. On the other hand I think
> it would be excellent to have CUPS as the *preferred* way to talk
> to printers, for all the reasons you outline below. To be able
> to just install it and have all the existsing printers come up in
> the print panel, PPD's and all, would be superb.

I think so too!


BTW, here is the general idea of how to use GSCUPS, it is really easy!

NSArray* destinations;
GSCUPSDestination *dest;
NSString *name;
GSCUPSPPDFile *ppdFile;
NSArray *pageSizes;
NSString *jclEnterPSCommand;
int languageLevel;
NSArray *uiGroups;  //Will contain GSCUPSPPDGroup's

destinations = [GSCUPS destinations];

//find the destnation you want
dest = [destinations objectAtIndex: whatever];
name = [dest name];
ppdFile = [dest ppdFile];

pageSizes = [ ppdFile pageSizes];
jclEnterPSCommand = [ppdfile jclEnterPScommand];
languageLevel = [ppdFile languageLevel];
uiGroups = [ppdFile uiGroups];  //returns an array of GSCUPSGroup's
///and on and on....






> > By writing GSCUPS I've become pretty up to speed with CUPS, so I could
> > probably add CUPS support for GNUSTEP using libcups directly, no need
> > for an objective-c wrapper (If that would bother you all)
>
> This might be the simplest solution for now - including GSCUPS inside
> GNUstep as it stands then gives programmers two different ways to talks
> to ornters, which isnt a good thing for portability. Having CUPS 
> invisible
> under-the-bonnet but driven by the normal OpenStep printing API would 
> be
> by far the best way to go I think... especially if you think it's 
> fairly easy
> to do so.

Personally, I would prefer to add the objective-c wrappers I have 
already written and put those directly in GNUstep.  Whatever is *not* 
transferred over would remain behind in the GSCUPS framework.

If I did this, the classes to be added to GNUstep would be:
GSCUPS.h/m
GSCUPSDestination.h/m       #This is an abstraction of either one 
printer or a pool of printers...along with the options associated with 
instances of those.

#Now the PPD stuff...
GSCUPSPPDAttribute.h/m
GSCUPSPPDChoice.h/m
GSCUPSPPDConstraint.h/m
GSCUPSPPDEmulator.h/m
GSCUPSPPDFile.h/m
GSCUPSPPDGroup.h/m
GSCUPSPPDOption.h/m
GSCUPSPPDProfile.h/m
GSCUPSPPDSize.h/m   #It's nothing like a NSSize... :-)

Not to bad for all the benefits that would be gotten.  I think that 
eventually a new dialog box would have to be created to take full 
advantage of CUPS capabilities though.



As for handling both type of printing systems, how to handle that?  Is 
the best was to simply read the users defaults and then use a different 
combination of NSPrinter/NSPrintInfo/NSPrintPanel.  It looks like 
NSPrintOperation should be same either way, on UNIX at least.


Chad


> -bat.