SUMMARY It's impossible to save any change in system configuration -> touchpad configuration, because the "Apply" button isn't activated. STEPS TO REPRODUCE 1. Start systemsettings 2. Go to Hardware -> Input devices 3. Go to Touchpad 4. Use first tab and change 2 finger mode to middle mouse key. 5. You could try to change any other parameter in any other tab. The apply button never gets activated. OBSERVED RESULT Apply button is not activated EXPECTED RESULT Apply button must be activated SOFTWARE/OS VERSIONS Linux/KDE Plasma: (available in About System) KDE Plasma Version: 5.24.0 KDE Frameworks Version: 5.90.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION
Reverting to 5.23.5 makes it working again.
*** Bug 449978 has been marked as a duplicate of this bug. ***
Cannot reproduce on Wayland, must be X11-specific.
I cannot reproduce on X11 either
Doesn't work with Wayland, either (regardless if amd or nvidia). BTW: I even tested with a fresh account (no existing historic configuration before - same problem). Can you say how to debug the problem?
Maybe you could provide some debug output to the source code to narrow down, where the problem happens? I'm able to recompile https://ftp.lysator.liu.se/pub/opensuse/repositories/KDE:/Frameworks5/openSUSE_Leap_15.3/src/plasma5-desktop-5.24.0-lp153.504.2.src.rpm and may add the debug output before ... .
I'm also on 5.24.0 and have the same problem, on both Wayland and X11. However, doing `kcmshell5 kcm_touchpad` in a terminal and configuring the touchpad in the window it opens, the 'Apply' button works.
I already tested the "konsole" workaround you described - doesn't work here either. Anyway I sometimes could see differences between start via konsole and start via icon in start menu: the two radio options for 2 finger tipping (right click or middle click) are often disabled when starting from start menu - after it has been started via konsole, they are active. If started from konsole, I'm getting the following debug output: ~> systemsettings kcm_touchpad kf.configwidgets: A widget named ' "kcfg_osdKbdLayoutChangedEnabled" ' was found but there is no setting named ' "osdKbdLayoutChangedEnabled" ' kf.configwidgets: A widget named ' "kcfg_repeatRate" ' was found but there is no setting named ' "repeatRate" ' kf.configwidgets: A widget named ' "kcfg_repeatDelay" ' was found but there is no setting named ' "repeatDelay" ' kf.configwidgets: A widget named ' "kcfg_resetOldXkbOptions" ' was found but there is no setting named ' "resetOldXkbOptions" ' kf.configwidgets: A widget named ' "kcfg_configureLayouts" ' was found but there is no setting named ' "configureLayouts" ' kf.configwidgets: A widget named ' "kcfg_repeatRate" ' was found but there is no setting named ' "repeatRate" ' kf.configwidgets: A widget named ' "kcfg_repeatDelay" ' was found but there is no setting named ' "repeatDelay" ' kcm_touchpad: Using X11 backend qml: Touchpad configuration of device '1 : ELAN1200:00 04F3:30BA Touchpad' opened file:///usr/lib64/qt5/qml/org/kde/kirigami.2/FormLayout.qml:283:9: QML QQuickItem* (parent or ancestor of QQuickLayoutAttached): Binding loop detected for property "preferredWidth" qrc:/libinput/touchpad.qml:108:5: QML FormLayout: Binding loop detected for property "implicitHeight"
*** Bug 450293 has been marked as a duplicate of this bug. ***
There's a weird "Q_EMIT changed(false);" in "TouchpadConfigContainer::resizeEvent", which would disable the Apply button on resizes. Can you set a breakpoint on KCModule::changed(bool) and for each call get the argument value as well as a backtrace?
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/852
Git commit 369eab6457965de99119f9966a009f98a60745bc by Fabian Vogt. Committed on 24/02/2022 at 20:25. Pushed by fvogt into branch 'master'. kcms/touchpad: Remove weird Q_EMIT changed(false) in resizeEvent That looks rather out of place there and does actually disable the apply button when resizing the window. I don't understand what it's supposed to be doing there, but if it has an actual purpose it needs to be addressed differently. M +0 -1 kcms/touchpad/kcm/touchpadconfigcontainer.cpp https://invent.kde.org/plasma/plasma-desktop/commit/369eab6457965de99119f9966a009f98a60745bc
Git commit 5cf2788fdd18cb8604fd172535b044c6cfd370fc by Fabian Vogt. Committed on 24/02/2022 at 21:05. Pushed by fvogt into branch 'Plasma/5.24'. kcms/touchpad: Remove weird Q_EMIT changed(false) in resizeEvent That looks rather out of place there and does actually disable the apply button when resizing the window. I don't understand what it's supposed to be doing there, but if it has an actual purpose it needs to be addressed differently. (cherry picked from commit 369eab6457965de99119f9966a009f98a60745bc) M +0 -1 kcms/touchpad/kcm/touchpadconfigcontainer.cpp https://invent.kde.org/plasma/plasma-desktop/commit/5cf2788fdd18cb8604fd172535b044c6cfd370fc
The proposed patch fixes the problem of not activated apply button for me. I tested against 5.24.2.