KDE4 printing: results of IRC meeting

Kurt Pfeifle k1pfeifle at gmx.net
Fri Sep 14 22:33:27 BST 2007

Thomas Zander wrote:
> On Friday 14 September 2007 20:45:11 Kurt Pfeifle wrote:
>> Thiago Macieira wrote:
>>> 3) Print to PDF and Print to PS are replaced by menu entries
>>>   This should probably be provided as a whole "Send To" or "Export
>>> to" QMenu standard action from kdeui, that we can extend with
>>> .desktop files or whatnot.
>> This only covers KDE applications then.
>> It looses the feature to "print to pdf" for nearly *any* other file
>> type (text, images, PS) when loaded into the standalone kprinter
>> dialog, as it is supported now when you selected "Convert" in the
>> dialog that comes up by printing non-PS files (well, maybe the feature
>> was lost through the bitrotting process in recent 12-18 months, but it
>> used to work fairly well).
>> I'm not complaining -- just want to make sure you're aware what gets
>> lost by the current changes.
> Maybe you can look into the following item we have on the TODO;
> question:  Can we add a 'virtual printer' to Cups which does nothing but 
> write to a file in a format like postscript or PDF ?

This is possible (even now) -- but it also opens a pandora's box of
security problems:

In order to allow a CUPS backend (virtual printer) to write to a user-
private file it would need to run as root. Something the developers
want to avoid at all costs...

Also, for the user it would require to have CUPS installed in the first
place, and have it working too, and the daemon started up...

Currently, for the "print to PDF" function you need neither of these
pre-conditions. "It just works....", which is a good reason to keep that
set of features (or at least design the new printing framework in a way
that makes it easy to bring back that support in KDE 4.1).

> If cups already has this functionality we can adjust our KCM to support 
> this, otherwise I hope someone can bring this up with the cups guys.

To configure CUPS (also for PDF printing), you need some sort of admin
privileges (not necessarily root -- depends on exactly how CUPS is

To use KDEPrint's current "print to PDF" feature, you can be a common
mortal user. And you don't need to configure CUPS first, and rely on it
to work....

> Bottom line;  in Windows + Mac adding a (virtual) printer is a system 
> setup, not something that the applications do.  In Unix we should aim to 
> do the same thing where the 'system' is Cups.

KDE in general does a *lot* of things (in many areas) that on Windows
and Mac "the system setup" is providing. So why use this argument for
printing only?

If this argument is valid for printing, it should be valid everywhere,
and you could chop off a substantial part of KDE4 and instead ask for
"the system" to provide the functionality. But you don't do that either
(nor do I want you to).

Kurt Pfeifle
System & Network Printing Consultant ---- Linux/Unix/Windows/Samba/CUPS
Infotec Deutschland GmbH  .....................  Hedelfinger Strasse 58
A RICOH Company  ...........................  D-70327 Stuttgart/Germany

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