Android Studio - Unique Lock Pattern Screen

Good morning,

I used this tutorial to try and understand how to make and use a Lock Pattern Screen inside my application :

https://www.youtube.com/watch?v=R8gm1eGU5CI

What I'm trying to do it's to prevent the user to go to the next Activity, unless they know the right pattern to unlock it (like a protected password would do). The thing is that I need to be able to define the pattern before and the user can't modify/define it. He's only able to try to enter the pattern.

Any lead or idea on how can I set the pattern programatically ?

Thanks in advance, have a great day !