Change keyboard layout in lockscreen / show virtual keyboard

[TheCataliasTNT2k]

Feature Request

In #107 there was a request, to show the current keyboard layout.
I now have a little related problem:

I may use different layouts, which not only move keys around, but replace them.
I use an on-screen keyboard to use these layouts while logged in.
Think of something like Cyrillic, Greek....

Obviously, I have a major problem, logging in without my normal letters....
I do not know, if you can change the layout via TTY for the lockscreen, but an option to set it in the lockscreen directly would be great....
Maybe "whitelist" some layouts you can choose from?
All "bigger" lock managers have something like this, like lightdm,...

Implementation

A button to change the keyboard layout while the screen is locked.
Or an on-screen keyboard, which has a predefined layout.

Have you planned working on this feature?

No (that is sadly over my abilities in this territory...)