How to write a custom slider?

Question

Objective-C

How to implement a custom slider (progressbar) for OS X applications?
You need something like a progress bar in iTunes:





Which way to dig?

Answer 1

I don't want to write trite things, but first of all google it:
stackoverflow.com/questions/3985816/custom-nsslidercell
stackoverflow.com/questions/8777953/mac-slider-custom-implementation-with-own-images