Is there a happiness philosophy that deals with philosophy toward preserving or increasing happiness of other people, not just how to be happy yourself? Main branch of philosophy I'm familiar with that kind of seems related is justice philosophy (Plato, Utilitarianism, Kant, and Rawls). I guess preserving justice is in a sense preserving other people's happiness, but it also seems like there are other ways to view other people's happiness as choosing how to be happy just seems like the part of a happiness philosophy one has more control over. It doesn't affect other people's happiness, but it seems like affecting other people's happiness might not just be justice philosophy.
I'm not majoring in philosophy or something, but I'm just curious how that has been best approached. I found this article listing some I'm not as familiar with in this realm. This does seem to tie into justice philosophy to an extent, but I'm guessing that isn't the full story right? Thanks for anything you can say about this topic.