Bug 479879

Summary:	Keyboard brightness controls with stepped values allows scrolling in between values
Product:	[Plasma] plasmashell	Reporter:	Antti Savolainen <antti.savo>
Component:	Brightness and Color widget	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	RESOLVED FIXED
Severity:	normal	CC:	fanzhuyifan, natalie_clarius
Priority:	NOR
Version First Reported In:	5.27.10
Target Milestone:	1.0
Platform:	Arch Linux
OS:	Linux
See Also:	https://bugreports.qt.io/browse/QTBUG-93081
Latest Commit:	https://invent.kde.org/plasma/libplasma/-/commit/249c56925682c478ef2b4be18cfc0b0fcefa2e92	Version Fixed In:	6.0
Sentry Crash Report:

Description Antti Savolainen 2024-01-16 04:44:56 UTC

SUMMARY
Demonstrative video: https://youtu.be/k41rchftoWg
If you have a backlit keyboard like the one in Thinkpad T470s, its brightness controls show up in the brightness control applet. The backlight is however stepped as in it's either off, dim or full as the brightness control shows. When dragging the slider with a mouse it works as expected but if you hover over it and use the trackpad to scroll, the slider goes to in-between values. This is purely cosmetic as it only affects the backlight when it hits one of the steps.

STEPS TO REPRODUCE
1. Have a backlit keyboard with set brightness levels
2. Open the brightness control applet
3. Hover your mouse over the keyboard brightness controls and use mouse scroll 

OBSERVED RESULT
The controls goes in-between the steps

EXPECTED RESULT
Scrolling should cause the control to hop to the next step

SOFTWARE/OS VERSIONS
Linux: Arch Linux
KDE Plasma Version: 5.27.10
KDE Frameworks Version: 5.114.0
Qt Version: 5.15.12

Comment 1 fanzhuyifan 2024-01-27 16:16:19 UTC

This is a known upstream Qt issue. https://bugreports.qt.io/browse/QTBUG-93081

See also: https://codereview.qt-project.org/c/qt/qtdeclarative/+/512061

Comment 2 fanzhuyifan 2024-02-13 20:03:21 UTC

Git commit aea3d4b131070d8388edf84c9c2a32f7b4203617 by Yifan Zhu.
Committed on 13/02/2024 at 20:01.
Pushed by fanzhuyifan into branch 'master'.

Slider: Fix slider scrolling direction

We always want the slider to increase its value when scrolling
up or right, no matter the inverted scrolling setting.

For "regular" scrolling, this corresponds to positive values on
the Y axis and negative values on the X axis. For "natural"
scrolling (indicated by the `inverted` property) is the opposite
so we need to reverse the sign.

Note that the Qt documentation on WheelEvent is dubious:
On https://doc.qt.io/qt-5/qml-qtquick-wheelevent.html, the
`angleDelta` section suggests that positive should be up/right,
but the `inverted` section indicates the above mentioned behavior.

This commit borrows from Slider.qml and
5d6d74ef68889da7400cb2a16a73527f1927424d in qqc2-desktop-style.
Related: bug 479028
FIXED-IN: 6.0

M  +38   -1    src/declarativeimports/plasmacomponents3/Slider.qml

https://invent.kde.org/plasma/libplasma/-/commit/aea3d4b131070d8388edf84c9c2a32f7b4203617

Comment 3 fanzhuyifan 2024-02-13 20:06:15 UTC

Git commit 249c56925682c478ef2b4be18cfc0b0fcefa2e92 by Yifan Zhu.
Committed on 13/02/2024 at 20:04.
Pushed by fanzhuyifan into branch 'Plasma/6.0'.

Slider: Fix slider scrolling direction

We always want the slider to increase its value when scrolling
up or right, no matter the inverted scrolling setting.

For "regular" scrolling, this corresponds to positive values on
the Y axis and negative values on the X axis. For "natural"
scrolling (indicated by the `inverted` property) is the opposite
so we need to reverse the sign.

Note that the Qt documentation on WheelEvent is dubious:
On https://doc.qt.io/qt-5/qml-qtquick-wheelevent.html, the
`angleDelta` section suggests that positive should be up/right,
but the `inverted` section indicates the above mentioned behavior.

This commit borrows from Slider.qml and
5d6d74ef68889da7400cb2a16a73527f1927424d in qqc2-desktop-style.
Related: bug 479028
FIXED-IN: 6.0


(cherry picked from commit aea3d4b131070d8388edf84c9c2a32f7b4203617)

M  +38   -1    src/declarativeimports/plasmacomponents3/Slider.qml

https://invent.kde.org/plasma/libplasma/-/commit/249c56925682c478ef2b4be18cfc0b0fcefa2e92