Hi

I'm experiencing a weird issue with all printing dialogs of KDE apps on openSuSE Leap 42.3, running KDE Frameworks Version 5.32.0, KDE Plasma Version 5.8.7:

All printing dialogs of KDE apps need lengthy 2-7 secs. to appear after clicking the print button
Once the printing dialog has surfaced, clicking on most of its buttons / pull down lists is equally laggy, but may even extend up to ~15 secs waiting time

This behavior is independent of:
- the printers installed. It even occurs for a completely empty printer cue and printing only to a PDF file.
- the machine being connected to a network.
- any per-user setting. It happens also for a fresh user.
- the hardware. It occurs on several completely different machines, all running openSuSE Leap 42.3, KDE Frameworks Version 5.32.0, KDE Plasma Version 5.8.7

Actually the issue even occurs if the KDE-app is invoked from a non-Plasma desktop, like IceWM or so.

In contrast to this, all non-KDE-apps on the respective machines do not show any of this laggy behavior. Their printing dialogs pop up immediately.

Any help to overcome this issue would be most welcome.

markwolf

Is this issue really only with KDE applications? Please try Qt5 applications, such as qpdfview. If you get the same issue there, it is a bug in Qt.

Actually it is a feature, added by SUSE.

See https://en.opensuse.org/Portal:42.3/Features :

Leap 42.3 carries a mature version of the Qt 5 GUI toolkit (5.6) LTS . Qt 5.6 has some non-critical security fixes in the Qt framework and in third-party libraries. Qt now detects remote print queues using avahi. This adds a delay the first time a print dialog is opened in an application. If you don't have any network print queues and you find the delay too annoying, it can be disabled by setting the QT_DISABLE_PRINTER_DISCOVERY environment variable to 1 in /etc/environment .

That solved it.

How can this be a 'feature'? Several apps typically 'exist' only for being popped up briefly and then to print once, eg. Okular. If in such apps you don't keep the app's window open and read in new files via the app's own 'open' dialog - which is very unusual on a mime-type driven system - you have to wait each and every printing process. And actually, having / or not having a network printer cue did not change the issue for me.

Anyway: thanks.

markwolf

markwolf wrote:How can this be a 'feature'?

Because somebody (at SUSE) thought it (automatic detection of network printers) would be a good idea and implemented it.
Unfortunately, as it often happens, nobody "complained" about problems during the testing phase before the release ...

Feel free to file a bug report at openSUSE's bugzilla.

There already is a recent one about a more severe problem anyway though:
http://bugzilla.opensuse.org/show_bug.cgi?id=1060735
The (currently) last comment suggests that it was actually supposed to be changed to be disabled by default, but this obviously hasn't happened yet.