Re: Printing Architecture Ideas

[Tom Tromey <tromey creche cygnus com>]

Zack> I noticed that there are not too many comments floating around
Zack> out there about the Gnome printing architecture. Here are just
Zack> some of my ideas

I read this message.

While I generally agree that Gnome should have some kind of built-in
printer support, I disagree with various details in your proposal.
Here is what I think we should do, and why:

* We probably don't need to deal with GUIs for configuring printers,
because hopefully that will be taken care of by COAS.  (Does anybody
know for sure?  I haven't read through all the COAS stuff.)

* We should try to be agnostic about the underlying print system
(i.e., lpr -vs- lp).  That will let Gnome work in existing networks
without change.  Requiring someone to install a new print system just
to have Gnome work would be bad.  (If this results in decreased
functionality, we could always arrange to have the extra stuff enabled
only if the system has the winning print system.)

Zack> 2. We should have a small biff like applications that gives the
Zack> printer status so that any sort of preference manipulation could
Zack> use it).

Is `gulp' insufficient in some way?  I've never used it in anger (I
hardly ever print things).

Zack> 3. We need a standard print dialog box. The one from gimp is far
Zack> too graphic specific. The print dialog should probably be set up
Zack> like the newer MacOS ones that are tabbed and have application
Zack> specific and printer specific options on different
Zack> pages. Options like n-up printing, printer resolution, and
Zack> watermarks could be set through this interface. This dialog
Zack> would also have a print preview function that would allow the
Zack> user to see what they are printing (and would make it so that
Zack> everything had built in print preview)

I agree we need a standard print dialog.  I don't know how fancy it
should be, though.

It might be appropriate to have different print dialogs for different
kinds of data (the primary ones being PS and plain text).  For
instance the plain text dialog might actually be an interface for
`enscript' (if it exists).

Zack> Should we have one logical printer (i.e.. lp) and then use the
Zack> gnome print filters select which physical one they will use (a
Zack> la MacOS that has a default printer, but you can change it in
Zack> the print dialog), or have multiple logical printers (i.e.. lp1,
Zack> lp2, etc.) that are set up for each logical printer, and require
Zack> the user to type in command line options?

It might be interesting to let users define their own "printers"
(which are a combination of some actual printer and some default
options).

Zack> How do we handle networked printers? On systems other than
Zack> Linux/Unix?

We don't handle them.  This is handled by the print subsystem.  There
are no systems other than Unix.

Zack> Do Gnome apps go through lpr to print (would work well on
Zack> systems without the gnome print system installed), or bypass it
Zack> and use the gnome print filters directly? (less overhead)

Always use lpr (or lp, or whatever command the sysadmin configures
in).  Another new print system is bad.


One random thought: if print requests use CORBA, then we can finally
print locally from remote machines where we don't have permission to
edit /etc/printcap.  I've occasionally wanted to do this.

Tom