Switch to LXDE-pi (Lightweight X11 Desktop Environment)

[jvolker]

This extension is currently using legacy x server components. We should switch to LXDE-pi which is the Pi version of Lightweight X11 Desktop Environment. I would expect performance improvements with it.

It's not hard to change it, I think. I found this german article about running Chromium in fullscreen using LXDE-pi: https://itrig.de/index.php?/archives/2309-Raspberry-Pi-3-Kiosk-Chromium-Autostart-im-Vollbildmodus-einrichten.html

I'm sure there are similar articles in English, but I'm happy to implement it and do a PR when I find the time for it.

[jvolker]

I did some more research.

xserver-xorg-legacy is really just a wrapper starting xserver with root rights like it used to be the case in older versions. This should be no different from regular LXDE and it seems to make sense to keep using xserver-xorg-legacy.

The above-mentioned article just explains how to add those commands to the LXDE-pi autostart. The syntax there seems slightly different using @. I'm not sure what language it is but it doesn't seem to be relevant for our use case as we want to start an xserver session with a single application.

That said, I'm not sure if our method of starting xinit with a single application is using LXDE or LXDE-pi. Maybe some performance tests comparing Openframe to command line can help understanding if there is a difference. I've started making some tests here:
https://openframe.discourse.group/t/raspberry-pi-performance-tests/124

I'm closing this for now as I don't think it's really an issue.