Created attachment 147823 [details] Screenshot of mouse settings SUMMARY Currently if the user uses X11, it is not possible to customize the scroll length of the mouse wheel. The reason of this is that when the libinput driver is in use for processing mouse events instead of the evdev driver, the mouse KCM in System Settings has different controls, which for example does not include the scroll length customization option. Despite this, manually editing the "[KDE]" section in the ".config/kdeglobals" file to have the "WheelScrollLines=X" (where X is a number) property will still have effect on Qt applications, so the user is able to customize the scroll length in at least some applications. The issue has been properly solved for Wayland in Bug 403842. The goal of this issue is to try to solve it at least partly for X11 too. As an example solution, a new control could be added to the version of the mouse KCM which appears for X11+libinput users, to customize the value of this option more easily. If this feature is added, the settings option should show a warning that currently it only applies to Qt applications. It might also worth it to extend the help section of said KCM with a notice on this control linking to this or the above mentioned bug for more information. SOFTWARE/OS VERSIONS Linux/KDE Plasma: openSUSE Leap 15.3 (available in About System) KDE Plasma Version: 5.24.3 KDE Frameworks Version: 5.92.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION There is one more thing, that could be related to this issue. When an X11 user uses the evdev driver for mouse events, the mouse KCM still has a control for customizing the mouse scroll length (named "Mouse wheel scrolls by"), though similarly to the above mentioned config file property, it seemingly only affects Qt applications. It might also worth to include the same note for this settings option. I've also attached a screenshot showing the current mouse KCM shown for X11+libinput users.
It looks like my message does not appear here. Well, here is what I have written: SUMMARY Currently if the user uses X11, it is not possible to customize the scroll length of the mouse wheel. The reason of this is that when the libinput driver is in use for processing mouse events instead of the evdev driver, the mouse KCM in System Settings has different controls, which for example does not include the scroll length customization option. Despite this, manually editing the "[KDE]" section in the ".config/kdeglobals" file to have the "WheelScrollLines=X" (where X is a number) property will still have effect on Qt applications, so the user is able to customize the scroll length in at least some applications. The issue has been properly solved for Wayland in Bug 403842. The goal of this issue is to try to solve it at least partly for X11 too. As an example solution, a new control could be added to the version of the mouse KCM which appears for X11+libinput users, to customize the value of this option more easily. If this feature is added, the settings option should show a warning that currently it only applies to Qt applications. It might also worth it to extend the help section of said KCM with a notice on this control linking to this or the above mentioned bug for more information. SOFTWARE/OS VERSIONS Linux/KDE Plasma: openSUSE Leap 15.3 (available in About System) KDE Plasma Version: 5.24.3 KDE Frameworks Version: 5.92.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION There is one more thing, that could be related to this issue. When an X11 user uses the evdev driver for mouse events, the mouse KCM still has a control for customizing the mouse scroll length (named "Mouse wheel scrolls by"), though similarly to the above mentioned config file property, it seemingly only affects Qt applications. It might also worth to include the same note for this settings option. I've also attached a screenshot showing the current mouse KCM shown for X11+libinput users.
Please ignore my second message, I misinterpreted the Bugzilla UI.
To solve it on X11 when using Libinput, the setting needs to be exposed in the driver itself, so that we can write to it in our config UI. One is in progress: https://gitlab.freedesktop.org/xorg/driver/xf86-input-libinput/-/merge_requests/12 We can't implement the feature without that, as it is needed to expose the setting to us.
(In reply to Nate Graham from comment #3) > To solve it on X11 when using Libinput, the setting needs to be exposed in > the driver itself, so that we can write to it in our config UI. One is in > progress: > https://gitlab.freedesktop.org/xorg/driver/xf86-input-libinput/-/ > merge_requests/12 > > We can't implement the feature without that, as it is needed to expose the > setting to us. I see, thanks for letting me know. Though why was the status set to resolved? As I understand, this feature currently cannot be implemented because it's blocked by the mentioned MR. According to the following page, the current status means the problem is not related to KDE, but the issue describes a missing feature in the system settings app. https://community.kde.org/Bugsquad/Quick_Introduction_to_Bugzilla
That page is quite old; See https://community.kde.org/Get_Involved/Issue_Reporting#Understand_what_the_resolution_statuses_mean
(In reply to Nate Graham from comment #5) > That page is quite old; See > https://community.kde.org/Get_Involved/ > Issue_Reporting#Understand_what_the_resolution_statuses_mean I see, thanks! Also, I'm new here and not familiar with the protocols, so another question: What should happen when that MR gets resolved? Should I reopen this ticket, or should I open a new one?
Once that's done, we could re-open this, or open a new one. It won't make much of a difference.