how to configure gnome to use only one specific keyboard layout on lock screen?

Question

for lock screen, gnome uses keyboard layout that was last used before locking the screen. Is there a possibility to configure gnome in such a way that it will always switch keyboard layout to some specific value for lock screen?

Example, how it works now: You have two layouts configured, en and abc. You've been entering some text using keyboard layout abc and then locked the screen by hitting Meta + L or placing your computer into sleep mode. Reaching lock screen, you find your keyboard layout is abc. You switch it to en and enter your password, unlock the screen and see that your active gnome desktop keyboard layout is abc.

Desired: You have two layouts configured, en and abc. You've been entering some text using keyboard layout abc and then locked the screen by hitting Meta + L or placing your computer into sleep mode. Reaching lock screen, you find your keyboard layout is en, because you managed to somehow configure gnome (or use some lock screen activation scripts/hooks?) to always switch to en for lock screen. Desktop keyboard layout after unlocking could be retained (abc), but this is of no importance in scope of given question.

Answer 1

I wrote a gnome extension, which resets keyboard layout when screensaver activates. You can access it on https://github.com/galets/gnome-keyboard-reset

Answer 2

You can install g3kb-switch to control current keyboard layout in GNOME from command line. To change keyboard layout to English on Lock Screen automatically, you can use a script (put it in GNOME autostart):

#!/bin/bash
dbus-monitor --session "type=signal,interface=org.gnome.ScreenSaver" |
  while read MSG; do
    MSG_STAT=`echo $MSG | grep boolean | awk '{print $2}'`
    if [[ "$MSG_STAT" == "true" ]]; then
      echo "Screen locking actions"
      gdbus call --session --dest org.gnome.Shell --object-path /org/g3kbswitch/G3kbSwitch --method org.g3kbswitch.G3kbSwitch.Set 0
    fi
  done

GNOME disables all extensions on Lock Screen activation for security reasons. So, you need to remove everything from disable() method in ~/.local/share/gnome-shell/extensions/[email protected]/extension.js as written here, then reboot.

Answer 3

found it!

Gnome Settings → Region & Language → Input sources section. Click on the «Login screen» button to modify input sources relevant to Login screen. The button itself resides on the window decoration bar and is "hidden openly", hard to find visually.