One of the areas I’m currently working on is improving our support for input devices in KWin. While general usage is already quite good in Plasma 5.6, we are not yet able to configure the input devices. This is something I’m working on to improve for Plasma 5.7.

Input devices are provided by libinput and KWin integrates with that for quite some time. What it didn’t do yet is to configure them and keep track of them.

So as a first step we created a Device wrapper class which encapsulates a libinput device in a way that we can easily use it from inside KWin. The Device allows us to gain knowledge about what it supports and also to configure it.

The used Devices and their states can be queried through KWin’s new Debug Console:



The Debug Console is also new in Plasma 5.7 and allows us to have a deeper introspection into KWin. It can be opened through KRunner (Alt+Space) and then with the command “KWin”. The functionality set is inspired by tools like xprop (one tab allows to read all window properties), xwininfo -tree (one tab shows a (sub)surface tree), xev (input events).

Back to input devices. Once we had the Device wrapper class in place we could start making use of it to configure devices. And today I landed a series of commits in KWin master which bring us back many features from X11. From the configuration point of view it’s really easy for us as we can just reuse our existing configuration tools. For example the mouse configuration module writes to a config file which KWin can read. When the settings change the configuration module sends out a DBus signal which KWin uses to trigger a reconfigure.

So KWin now supports setting pointer devices (mouse) to left-handed usage and modifying the pointer acceleration.



In addition KWin started to integrate changes for touchpads. KWin listens to the global shortcut for touchpad toggle and uses this to enable/disable the touchpad. Of course this comes with triggering the new on-screen-display notification for enabling the touchpad. Next step will be to integrate more options for touchpads, but this will require writing a kwin-backend for our touchpad control module.