Unplugging external monitor forces me to reboot

Question

I use a script that runs xrandr to turn off laptop display, showing only the external monitor screen.

I have another script that basically "reverses" this (showing only laptop display) which I use every time I have to take my laptop to a coffee shop.

Sometimes, in a hurry, I don't do this and just unplug my laptop directly before putting it in the bag. Now when I reach the coffee shop and try to use it, I would only see a blank screen which is due to what I assume to be my video configuration still being in "external screen only" mode. Question: how do I go to "laptop screen only" mode here? Otherwise, is there a way I can avoid having this problem in the first place?

Without knowing this I simply force reboot my laptop, which sucks.

For the record I run NixOS on Thinkpad P71.

Answer 1

This answer suggests, no event is fired on a monitor connect/disconnect event. If it is really so, then it is a major bottleneck of the Linux/X11 GUI in my opinion.

That answer suggests polling as a workaround (xrandr --listmonitors shows the connected / disconnected monitors, executing a script periodically would be a solution).

However, polling is bad. A better option would be to bind a monitor fixer script to a keyboard shortcut. Write a script, which

1. gets the a list of the connected/disconnected monitors
2. turns off always the one what you want (depending on, which is connected)
3. bind its execution to a keyboard shortcut.

Answer 2

As an short term fix to avoid reboot, unlock your screen, hit the keyboard shortcut to open terminal, and run xrandr --output eDP1 --auto to turn on your monitor again. You can do all of that 'blind' while your monitor is disabled.