On Thu 04 Jan 2018 at 16:53:30 -0200, Till Kamppeter wrote: > I have opened this Blueprint when CUPS 1.6.x was under development and in > this version CUPS' print queue broadcasting and browsing was dropped. The > DNS-SD broadcasting was supposed to replace it but it was missing out > automatic print queue creation on CUPS clients. > > I actually solved the problem by adding cups-browsed which introduced > automatic print queue creation based on DNS-SD broadcasts from remote CUPS > servers. > > This required CUPS, cups-browsed, and avahi-daemon running on the client.
This is indeed my understanding. To my mind, this is now the basis of remote printer/print queues discovery and display for applications and commnad line utilities on a client. I have found it to work very well. > Your observation of a recent LibreOffice version showing printers in its > print dialog with CUPS and cups-browsed stopped is only possible if the > print dialog itself grabs DNS-SD broadcasts of remote printers and lists > these printers. Assuming it is correctly implemented it talks IPP to the > printers/remote CUPS queues directly, without using a locally running CUPS > daemon. Not that I didn't believe it, but I have checked a number of times that it is so (libreoffice 1:5.4.4-1). The naming of the queues/printers is not the same as in the GTK dialog and, with cups-browsed running, there is no duplication (#877713). > The latest approach is the new CPDB (Common Print Dialog Backends) project > of OpenPrinting. It was developed in the GSoC 2017 and was already > introduced on this mailing list (see srchives). I saw the the announcement and look forward to CPDB's release and having the opportunity to test it. > Print dislogs are supposed to communicate with printing systems (CUPS, > Google Cloud Print, Print to file, ...) only through backends, so that new > printing systems only need a new backend to get supported under all apps and > changes in printing system require only changes in the corresponding > backend, not in each dialog. > > LibreOffice has accepted the changes for supporting this concept, but it is > needed that Debian accepts the new packages with the libraries and the > backends, see earlier postings (unfortunately all unanswered) on this list. LibreOffice has obviously resonded positively to the Blueprint but, after quite extensive searching, I can find nothing relating to where and when the final decision was made. Release Notes, mailing lists and changelogs are silent. It is a small point but, still, part of the big picture. There must be a reason for the Blueprint's page to record > Bug #1083757: LibreOffice Print dialog needs to support Bonjour > broadcasting of remote printers Fix Released (BTW: Qt 5 now supports remote print queues. The "IDEs and tooling" section at https://en.opensuse.org/Portal:42.3/Features). Cheers, Brian.