ViewController + Extensions.swift

// MARK: - Keyboard Insets
extension UIViewController {
    
    internal func updateInsets(for event: KeyboardEvent, scrollView: UIScrollView?) {
        guard let scrollView = scrollView else { return }
        
        let newKeyboardFrame = event.keyboardFrameEnd
        let duration = event.duration
        
        let newKeyboardHeight = newKeyboardFrame.origin.y < UIScreen.main.bounds.height ? newKeyboardFrame.height : Sizes.zero
        updateInsets(duration: duration, keyboardHeight: newKeyboardHeight, scrollView: scrollView)
    }
    
    private func updateInsets(duration: TimeInterval? = nil, keyboardHeight: CGFloat = Sizes.zero, scrollView: UIScrollView) {
        let bottomInset: CGFloat
        let insets: UIEdgeInsets
            bottomInset = keyboardHeight > 0.0 ? keyboardHeight - view.safeAreaInsets.bottom : Sizes.zero
            insets = scrollView.contentInset.bottom(bottomInset)
        }
        
        if let duration = duration {
            UIView.animate(withDuration: duration) { [weak self] in self?.updateInsets(insets: insets, scrollView: scrollView) }
        } else {
            updateInsets(insets: insets, scrollView: scrollView)
        }
    }
    
    private func updateInsets(insets: UIEdgeInsets, scrollView: UIScrollView) {
        scrollView.contentInset = insets
        scrollView.scrollIndicatorInsets = insets
    }
}