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OpusOne

Member

Registered: 2023-05-31

Posts: 194

Latest Qt6 update: mouse wheel stopped working to scroll through tabs

Hi, as the title suggests: it looks like the latest Qt6 update (6.12.0) broke a feature that I found very useful: scrolling through tabs in a tabs widget in Qt apps using the mouse wheel.
Just hovering over any tab in the tab header area and scrolling with the mouse wheel would just scroll through the different tabs.
That stopped working with the latest update.

Context is: I'm on Plasma/Wayland, if that makes a difference.

There has been a "concurrent" update of kwin so I'm not entirely sure if this comes from a Qt6 or kwin change.

The mouse wheel operates normally in all other situations, so this only seems to affect scrolling through tabs.

Wondering if I'm the only one even using that feature (which is very handy when there's a lot of tabs open) and/or if others have noticed it too.
If you are on the same environment (Plasma/Wayland) and using Qt6 apps with tabs, let me know.

Last edited by OpusOne (2026-10-09 02:58:14)

willvar

Member

Registered: 2026-10-11

Posts: 2

Re: Latest Qt6 update: mouse wheel stopped working to scroll through tabs

I can reproduce this with qt6-base 6.12.0-2 on Plasma Wayland.

This appears to be a Qt regression rather than a KWin issue. Qt's Wayland backend reports the PixelScroll capability for the touchpad device, but mouse wheel events may also be attributed to that device. QTabBar then takes the pixel-scrolling path instead of the discrete tab-switching path.

I built and tested a patched Arch package based on qt6-base 6.12.0-2:
https://github.com/willvar/qt6-base-tabbar-wheel-fix

Related discussions:
https://codereview.qt-project.org/c/qt/qtbase/+/778943
https://discuss.kde.org/t/mouse-scroll- … oken/50837

As a temporary workaround, affected applications can be run through XWayland or X11, although this is an undesirable workaround:
    QT_QPA_PLATFORM=xcb dolphin

OpusOne

Member

Registered: 2023-05-31

Posts: 194

Re: Latest Qt6 update: mouse wheel stopped working to scroll through tabs

Thanks!

tekstryder

Member

Registered: 2013-02-14

Posts: 595

Re: Latest Qt6 update: mouse wheel stopped working to scroll through tabs

Upstream commit cherry picked into pkgrel 6.12.0-3, now in [Extra].

• https://gitlab.archlinux.org/archlinux/ … ac47a55f1c

willvar

Member

Registered: 2026-10-11

Posts: 2

Re: Latest Qt6 update: mouse wheel stopped working to scroll through tabs

Thanks for the update! I've updated the repository README to recommend the official qt6-base 6.12.0-3 package instead of the local workaround.