I want a simple timeline component (like in video editing software) for a clojure/seesaw app and I am wondering if it is a good approach to implement this directly with clojure and seesaw or if I should write it in java and make my clojure wrapper around it. Or more generally: is a functional programming language optimal for writing UI widgets? I cannot imagine doing that without a lot of state involved. And wasn't OO invented for UI-development in the first place?