Paddle collision angle

Question

I'm making a breakout game to try to learn Swift. I'm looking to do something similar to what they're doing here - Breakout Paddle Collision Angle

Picture of angles

Currently, I'm using UIKit Dynamics to track collision behaviors. I have a UIView as a paddle, and a UIView as a ball.

I have no clue how to implement this and I'm wondering how it'd be done in swift. How would I go about doing this?

Thanks