Bug 411721 - Languages list flickers, making selection impossible
Summary: Languages list flickers, making selection impossible
Status: VERIFIED BACKTRACE
Alias: None
Product: systemsettings
Classification: Applications
Component: kcm_language (show other bugs)
Version: unspecified
Platform: Neon Linux
: NOR normal
Target Milestone: ---
Assignee: Eike Hein
URL:
Keywords:
: 415006 418556 420017 (view as bug list)
Depends on:
Blocks:
 
Reported: 2019-09-08 18:10 UTC by Thiago Sueto
Modified: 2022-02-01 12:03 UTC (History)
11 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Had to make a different video from what was described, original file was larger than limit. (3.30 MB, video/x-matroska)
2019-09-08 18:15 UTC, Thiago Sueto
Details
Managed to record one instance in which the glitch fixes itself. Also, RAM increase. (2.62 MB, video/x-matroska)
2019-09-08 18:21 UTC, Thiago Sueto
Details

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Description Thiago Sueto 2019-09-08 18:10:52 UTC
SUMMARY
I just encountered the weirdest graphical glitch. It occurs when this KCM is maximized, regardless of being run directly from terminal or krunner (kcmshell5 kcm_translations) or from System Settings.

When the window is maximized and the Add languages… button is pressed, the glitch will occur in a non-consistent manner. In addition, CPU immediately increases and RAM will slowly but surely increase. It seems to be a loop.

I was not able to determine what makes the language list open correctly when the KCM window is maximized. It occurred in the attachment by mere chance.

If the glitch is in process and the window is restored (a.k.a. loses its maximized state), the language list returns to normal.

When the window is not maximized, it works as intended.
I am on Xorg, not Wayland. Will test if this occurs on Wayland too.
The screen is 1920x1080. My GPU is AMD.
System Settings version: 5.16.80
Maybe it's relevant that I'm using KDE neon Unstable.

STEPS TO REPRODUCE
1. Maximize System Settings, go to Regional Settings
2. Click Add languages…
3. The glitch occurs most times
*. It's better to see the attachment yourself.

SOFTWARE/OS VERSIONS
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.16.80
KDE Frameworks Version: 5.62.0
Qt Version: 5.12.3
Kernel Version: 5.0.0-27-generic
OS Type: 64-bit
Processors: 4 × Intel® Core™ i5-7200U CPU @ 2.50GHz
Memory: 7,7 GiB

ADDITIONAL INFORMATION
The mouse effect is there just for depicting mouse clicks. It does not interfere with the reproducibility of the glitch.
Comment 1 Thiago Sueto 2019-09-08 18:15:37 UTC
Created attachment 122543 [details]
Had to make a different video from what was described, original file was larger than limit.
Comment 2 Thiago Sueto 2019-09-08 18:21:15 UTC
Created attachment 122544 [details]
Managed to record one instance in which the glitch fixes itself. Also, RAM increase.
Comment 3 Thiago Sueto 2019-09-08 22:00:04 UTC
Just checked, this also occurs on Wayland.
Comment 4 Patrick Silva 2019-10-27 12:03:18 UTC
I can confirm this issue with Plasma 5.17.1 at least on Wayland session.

Operating System: Arch Linux 
KDE Plasma Version: 5.17.1
KDE Frameworks Version: 5.63.0
Qt Version: 5.13.1
Comment 5 Patrick Silva 2019-10-27 12:07:11 UTC
This bug also occurs if system settings is configured to icon view.
Comment 6 Patrick Silva 2019-11-15 20:04:36 UTC
*** Bug 414187 has been marked as a duplicate of this bug. ***
Comment 7 Patrick Silva 2019-12-10 10:40:22 UTC
*** Bug 415006 has been marked as a duplicate of this bug. ***
Comment 8 Ferenc Lutischan 2019-12-10 11:41:55 UTC
I can confirm this issue exists in:

Operating System: Ubuntu 18.04 (KDE Neon user edition)
KDE Plasma: 5.17.4
KDE Frameworks Version: 5.64.0
Qt Version: 5.13.2
Comment 9 Patrick Silva 2020-01-28 22:59:59 UTC
This problem also affects Plasma 5.18 beta. When it occurs, makes language selection impossible.

Operating System: Arch Linux 
KDE Plasma Version: 5.17.90
KDE Frameworks Version: 5.66.0
Qt Version: 5.14.1
Comment 10 Bob English 2020-02-07 08:50:55 UTC
Happens on my both of my boxes too, One is AMD based and the other Intel, both are running the same OS, and are up to date. 

Operating System: EndeavourOS (Arch)
KDE Plasma Version: 5.17.5
KDE Frameworks Version: 5.66.0
Qt Version: 5.14.1
Kernel Version: 5.5.2-arch1-1
OS Type: 64-bit

Processors: 4 × Intel® Core™ i5-2500K CPU @ 3.30GHz
Memory: 31.3 GiB of RAM
Nvidia Graphics

and

Processors: 4 × AMD Phenom (tm) II X4 810 Processor
Memory: 5.6 GiB of RAM
AMD Graphics

Makes no difference if the windows are maximized or minimized, nor what theme is used.  )<:
Comment 11 Patrick Silva 2020-03-07 10:23:26 UTC
*** Bug 418556 has been marked as a duplicate of this bug. ***
Comment 12 postix 2020-03-07 10:26:02 UTC
Here's the terminal output while it's flickering:

bash: warning: setlocale: LC_ALL: cannot change locale (de_DE.UTF-8)
systemsettings5 
QQmlEngine::setContextForObject(): Object already has a QQmlContext
kf5.kactivity.stat: [Error at ResultSetPrivate::initQuery]:  QSqlError("1", "Command could not be executed", "no such column: rl.initiatingAgent")
kf5.kactivity.stat: [Error at ResultSetPrivate::initQuery]:  QSqlError("1", "Command could not be executed", "no such column: rl.initiatingAgent")
QQmlEngine::setContextForObject(): Object already has a QQmlContext
kf5.ki18n: "1 instead of 2 arguments to message {The translation file...} supplied before conversion."
file:///usr/share/kpackage/kcms/kcm_translations/contents/ui/main.qml:44: TypeError: Cannot read property 'display' of null
file:///usr/share/kpackage/kcms/kcm_translations/contents/ui/main.qml:40: TypeError: Cannot read property 'LanguageCode' of null

... repeated for each flickering in the video:

file:///usr/share/kpackage/kcms/kcm_translations/contents/ui/main.qml:44: TypeError: Cannot read property 'display' of null
file:///usr/share/kpackage/kcms/kcm_translations/contents/ui/main.qml:40: TypeError: Cannot read property 'LanguageCode' of null
Comment 13 Patrick Silva 2020-04-13 17:27:52 UTC
*** Bug 420017 has been marked as a duplicate of this bug. ***
Comment 14 John Little 2020-05-09 22:15:25 UTC
I get this on two fresh Kubuntu 20.04 installs, but not on a Kubuntu 20.04 install release upgraded from 19.10, all on the same desktop with Intel graphics.  Maximizing the settings window has not worked.
Comment 15 Patrick Silva 2020-05-09 22:23:12 UTC
For me this issue is fixed since update to frameworks 5.69 on Arch linux.
Comment 16 Paul L. 2020-05-09 22:59:34 UTC
Kubuntu 20.04, installed while it was beta, and updated daily up through final release and updated daily since.

KDE Plasma 5.18.4
Frameworks 5.68.0
Qt 5.12.8
Kernel 5.4.0-29-generic
OS 64-bit
Intel Core Processor Integrated Graphics (driver: i915)

I do not experience this behavior. System Settings window maximized and clicking on Regional Settings then on Add languages... presents the selectable language list without any issues.
Comment 17 John Little 2020-05-10 04:05:17 UTC
After reading the comments here about maximizing the window as a workaround, I tried again. No variation on maximizing avoided the problem, but making the settings window as small as it would go did.  Invoking the screen by running kcmshell5 translations also exhibits the problem, and there it was reproducibly sensitive to the window height; exactly 800 pixels or more would cause the flickering, on a 1920x1080 screen.

But I'm happy, I have a workaround.
Comment 18 postix 2020-07-12 15:37:33 UTC
Can no longer confirm on

Operating System: Manjaro Linux 
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.71.0
Qt Version: 5.15.0
Comment 19 Puspam Adak 2020-08-17 10:06:49 UTC
My PC have the same specs as yours. I have also faced this issue on Plasma 5.18.5. But, in my case, the dialog doesn't stop flickering even when the window is unmaximized.

If I enable the desktop effect "Dialog Parent" (which darkens the parent window when a dialog pops up), then the dialog stops flickering on unmaximizing the window. Looks like an infinite loop issue.
Comment 20 C 2021-08-09 19:00:30 UTC
Verified on

Operating System: Kubuntu 20.04
KDE Plasma Version: 5.18.7
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8
Kernel Version: 5.11.0-25-generic
OS Type: 64-bit
Processors: 3 × AMD Ryzen 5 3600 6-Core Processor
Memory: 3.8 GiB of RAM

Does not happen on my Latitude 7480 (running on bare hardware) but while everything else runs very smooth, this particular menu is very choppy.
Comment 21 Matthew Forrester 2022-02-01 12:03:50 UTC
I also have this issue. The workaround to reduce the size of the window works for me.

Operating System: Ubuntu 20.04 [with plasma-desktop package]
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8
Kernel Version: 5.13.0-27-generic
OS Type: 64-bit
Processors: 8 × AMD Ryzen 5 3400G with Radeon Vega Graphics
Memory: 13.6 GiB of RAM