Bug 435403

Summary:	[Wayland] Can't scroll in Chromium while moving the cursor
Product:	[Plasma] kwin	Reporter:	Jacob Kauffmann <jacob>
Component:	input	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	butirsky, daduck10, matt, nate
Priority:	NOR	Keywords:	wayland-only
Version First Reported In:	5.21.3
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Desktop session

Description Jacob Kauffmann 2021-04-06 02:29:47 UTC

SUMMARY
In Chromium-based browsers (including Chromium, Brave, and Vivaldi), scrolling with the scrollbar on an external mouse only works while the mouse cursor is not being moved.

In other words, if I'm moving the mouse at all, I cannot scroll at the same time. If I'm already scrolling and I start to move the mouse, scrolling stops.

STEPS TO REPRODUCE
1. Open Chromium and navigate to a long page
2. Start moving the mouse
3. Attempt to scroll while still moving the mouse

OBSERVED RESULT
As long as the mouse is moving, scrolling does not occur.

EXPECTED RESULT
I should be able to scroll while moving the mouse in Chromium-based apps the same as in all other apps.

SOFTWARE/OS VERSIONS
Linux: 5.10.27-1-lts
KDE Plasma Version: 5.21.3
KDE Frameworks Version: 5.80.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
- I've confirmed the issue happens in a brand new user account.
- I've confirmed the issue does not happen in a GNOME/Mutter Wayland session.
- This issue has never occurred in Plasma/KWin on X11.
- I'm using AMD graphics, the OpenGL 3.1 compositor, and libinput 1.17.1.
- The issue occurs whether I launch the session from SDDM or GDM.
- The issue does not occur with Falkon or Firefox.

Comment 1 Nate Graham 2021-04-06 14:52:47 UTC

So this is only happening in a Plasma Wayland session?

Comment 2 Jacob Kauffmann 2021-04-06 15:18:43 UTC

> So this is only happening in a Plasma Wayland session?
Correct. It happens in Plasma Wayland, it does not happen in GNOME Wayland or Plasma X11. Please let me know what other info I can provide.

Comment 3 Nate Graham 2021-04-06 15:56:49 UTC

Gotcha, thanks. I'll hand this over to the KWin people now. :)

Comment 4 daduck10 2021-05-11 17:36:21 UTC

I don't no if it helps, but in Kubuntu 21.04 I have the same problem in wayland session.

Comment 5 Andrey 2021-05-26 10:58:12 UTC

What is your Chromium version and where did you get it?
I'm trying to run the one shipped with Ubuntu and not able to run it on Wayland so far:
$ chromium -enable-features=UseOzonePlatform -ozone-platform=wayland
[43002:43002:0526/134002.060448:ERROR:wayland_connection.cc(123)] Failed to connect to Wayland display
[43002:43002:0526/134002.060502:FATAL:ozone_platform_wayland.cc(170)] Failed to initialize Wayland platform
Trace/breakpoint trap (core dumped)

Comment 6 Andrey 2021-05-26 11:17:23 UTC

Also, are you running Chromium as native Wayland client or XWayland?
It seems to me it runs XWayland by default here.

Comment 7 daduck10 2021-06-09 12:25:25 UTC

Created attachment 139134 [details]
Desktop session

Comment 8 Andrey 2021-06-15 12:50:36 UTC

I suppose you guys are still running Chromium as X11 client (XWayland).
Could you please confirm?
xwininfo command should let you know, please see here:
https://fedoraproject.org/wiki/How_to_debug_Wayland_problems#Does_your_application_run_on_Wayland_natively.2C_or_uses_XWayland_.28X11_compatibility_layer.29.3F

Also, if it's the case, please try to reproduce on pure Wayland client, as I noted above:
$ chromium -enable-features=UseOzonePlatform -ozone-platform=wayland

Comment 9 Andrey 2021-06-17 21:56:01 UTC

Couldn't reproduce on 2 systems: Plasma built from sources and KDE Neon Testing (Plasma 5.22.1).
As noted above, Chromium runs XWayland by default, and I couldn't run it as pure Wayland client due to the crash.

So please provide Chromium version and other details if it still happens to you, then reopen.