Adding support for the Common Print Dialog Backends (CPDB)

[Till Kamppeter]

On 27/03/2024 18:11, Michael Weghorn wrote:
> Good, then I currently see no blocker for requiring CPDB for CUPS 3.x support. 
> Distros will then become aware once they're packaging any software depending on 
> CPDB at latest.
>

Would be good to tell them that for CUPS 3.x use of CPDB is required.

For CUPS 2.x the direct CUPS interface can be used and CPDB also works with CUPS 
2.x (CPDB works with any CUPS).

For having a correct CPDB mode in LibreOffice, it must be possible to build 
LibreOffice without libcuops. If LibreOffice still needs libcups when in CPDB 
mode, this is a bug (of LibreOffice).

For the direct CUPS interface it needs to be checked whether IPP print 
destinations without having a permanent CUPS queue get listed. If this does not 
work, this is a bug in the direct CUPS interface, which either needs to get 
fixed or the direct CUPS interface be removed altogether.

Note that most distros have cups-browsed running which auto-creates permanent 
CUPS queues for IPP print destinations. This is a workaround for the bug that 
some print dialogs do not list IPP print destinations without a permanent CUPS 
queue. Turn off cups-browsed and remove all CUPS queues which it has 
auto-created (with implicitclass://... URIs) to check whether the direct CUPS 
interface of LibreOffice is correctly working.

> Yes, that makes sense. (For the CPDB case, we won't want to use CUPS directly 
> anymore, as CPDB API should be providing everything that's needed, as you 
> mentioned earlier.)

Yes, exactly this.

    Till