kscreenlocker-auto-screen-off

This is a small Python script that I wrote because I was very annoyed with the fact that, at the time of writing, the KDE lockscreen doesn't support shutting off the screen automatically after n minutes of time have passed in which no input (e.g. keyboard / mouse) was detected (like how you would expect a lockscreen to work).

There is a workaround that makes the screen immediately be turned off when the screen is locked. This is not ideal because if I wake up the screen and don't unlock my computer and walk away again, the screen will not be locked again, and of course the screen is also immediately turned off which I do not want.

However, I'm using a part of the answer myself.

How It Works

The script needs xinput, xset, pgrep and kscreenlocker to work.

If you lock your screen and don't touch your mouse and keyboard for 5 minutes, the screen will automatically be turned off. If you move your mouse, your screen should wake up and you should see your lockscreen. If you repeat this and wait another 5 minutes, the screen will be turned off again, until you unlock your session.

To do this, the script will…

acquire a list of all slave input devices by running xinput --list --short,
parse out the relevant device IDs,
for each ID, run xinput --test $id as a subprocess, and
merge all their stdout streams to one stream that has a timeout of one second.
If this timeout passes, this means, that no xinput instance has produced any output in the last second, i.e. no input device has been used.
If however input is done, this is immediately detected and we update a timepoint variable.
We measure the time since the last input.
If this time is larger than the configured timeout, we lock the screen using xset dpms force off.
If the screen is not locked anymore, i.e. kscreenlocker is not running, the script kills all subprocesses and exits.

How To Use

Clone the repo whereever you want:

$ git clone https://github.com/felsenhower/kscreenlocker-auto-screen-off

Run the script normally to test if everything works as intended. Output should look something like this:

$ cd kscreenlocker-auto-screen-off
$ python3 ./auto-screen-off.py
Found device IDs [4, 8, 9, 11, 5, 6, 7, 10, 12, 13, 14]
Spawning 11 xinput subprocesses…
Screen is not locked. Exiting…

Set the variable timeout_s in the script to your liking, default is 5 minutes.

Link the Lock screen to the script. Here is how to do it in KDE Plasma 5.20.4:

Go to the System Settings
Scroll down to "Personalisation" → "🔔 Notifications"
Click on "Applications: ⚙️ Configure…" at the very bottom
Scroll down to "System Services" → "🔒 Screen Saver"
Click on "🗨️ Configure Events…"
Select the "Screen locked" event at the top
Activate the checkbox "☑ ⚙️ Run command"
Enter /usr/bin/python3 "/path/to/your/auto-screen-off.py"
Click "✔ OK"

Alternatively, just edit your ~/.config/ksmserver.notifyrc so that it looks like this:

[Event/locked]
Action=Execute
Execute=/usr/bin/python3 "/path/to/your/auto-screen-off.py"
Logfile=
Sound=
TTS=

[Event/unlocked]
Action=
Execute=
Logfile=
Sound=
TTS=