Have you ever encountered a personality like this? What is it?

A person who has no interest nor curiosity in anyone, or anything, outside of what they are doing, right now. They can only talk into your face about random things that they are doing at the moment. It’s like your not even there? They may ask you a question, but as you’re are getting the words out of your mouth in answer, they are onto some other entirely unrelated thing? What is this and have you ever met someone like this?