I have a few little Java applets that I've been meaning to port to processing.js now that Java is considered harmful. First I needed a little class of sliders and buttons. There are a couple capable ones out there like controlP5, but they turn out not to work in pure JavaScript. So I wrote my own, based heavily on the "Scrollbar 0.12" by "raron". I will put this up on Github Real Soon Now, but for now here ya go: