Audio Animation in iOS

Audio animation?

Consider an imaginary touch-based slider control for use in an audio app: you drag your finger up and down the control (let’s imagine it’s a vertical slider) and some aspect of the sound changes in direct response to the movements of your finger.

But if you lift your finger and touch down again some distance from your previous touch – that is, you cause the control to make a jump in values – the control’s display gently but swiftly animates to that new value… and so does the audio!

So how would you do something like that?

With Core Animation of course!