This is a relatively simple file player that lets you scrub forward and backward in an audio file.
It should be noted that it's not *exactly* scrubbing because the playback speed is not changed, it's simply that the position in the song is changed by very small increments when fast-forwarding or rewinding. But the end result is convincing enough.

The positioning code is inside of the Play, Rewind, and Forward classes, which are in button.pde.

Source code: Scrubbing button

Built with Processing