How to use a pattern lock screen with lightDM/something similar in Xubuntu?

I am using Xubuntu in an ARM tablet. Every once in a while, the screen locks and I have to enter the password in lightdm. Is there any way to replace the password lock with a pattern lock in the lock screen? I am open towards replacing lightdm with other lockscreen managers. The answer to this question says that you can you face unlock or fingerprint, which is not what I want.