You should be able to solve this with getting the height of the bottomBar and using scrollview contentInsets and scrollIndicatorInsets.

bottomBarHeight should be the value of the bar height.

Example:

let contentInset = UIEdgeInsets(top: 0.0, left: 0.0, bottom: bottomBarHeight, right: 0.0)

scrollView.contentInset = contentInset
scrollView.scrollIndicatorInsets = contentInset

This is something that I use when I have scrollview and keyboard popup where i fille up the forms. Usually I make two @obj func where I will get notification with keyboard popup and keyboard hide where I reset contentInset to 0 values.