At some point we should consider tablets and alike and show an on screen keyboard for logging in. No idea, how to do this.
The KDM login manager allows this somehow, at least the openSUSE distribution by default detects TabletPC computers, and automatically starts xvkbd when kdm is started.
Update: I have a branch which shows the plasma keyboard applet.. However it doesn't work as the plasma keyboard applet is completely broken as it takes focus when clicked and therefore keys don't reach the input. This happens when added to the desktop too. I believe Plasma Active now uses Mailit, which is probably worth towards working towards.
Had a discussion with Aaron, active is moving towards using Maliit. We should support this. In theory - this only means starting the maliit server and the rest will work (in practice, this isn't working... needs investigation)
There is a technical issue in how Plasma Active is currently using Maliit, which requires a compositing window manager. What is used for login screen in Plasma?
We no longer use lightDM, having moved to SDDM several years ago. As such, this bug report is no longer applicable. Bugs reports for the new SDDM-based login screen should be filed to one of two places: 1. Visual/UI bugs with the login screen UI itself, or feature requests: plasmashell | Theme - Breeze 2. Bugs with the login/user switching process: https://github.com/sddm/sddm/issues