@thisissoon/angular-scroll-collapse
A simple lightweight library for Angular that detects scroll direction and adds a 'sn-scrolling-up' or 'sn-scrolling-down' class to the element. The library can also detect when the user has scrolled passed the element and apply a 'sn-affix' class. Useful
jquery.isinview
Detects if elements are in view - inside of the viewport, an iframe, or other containers. Extremely fast.