Abstract classes to easily create pull to refresh controls.
Why Another Pull To Refresh Library? There are lots of PTR libraries out there but none that fit 100% of my needs. PTR controls are awesome when completed but tedious to make. I made this so I would always be able to jump right into the custom animation, and not having to worry about customization. All you have to do for my implementation is override a few abstract methods detailing height, animation duration, and what gets run each animation cycle.