 private struct TextView {
     static let CornerRadius: CGFloat = 10
     static let WidthMargin: CGFloat = 10
-    static let Height = UIScreen.mainScreen().bounds.size.height / 5
+    static let Height = UIScreen.main.bounds.size.height / 5
 }
 
 internal class ButterflyTextView : UITextView {

        let frame = CGRect(
            x: TextView.WidthMargin,
            y: -TextView.Height,
            width: UIScreen.mainScreen().bounds.size.width - 2 * TextView.WidthMargin,
            height: TextView.Height)
        super.init(frame: frame, textContainer: nil)
        layer.cornerRadius = TextView.CornerRadius

    func hide() {
        if isShowing == true {
            isShowing = false
            UIView.animate(withDuration: 0.5,
                delay: 0,
                usingSpringWithDamping: 0.5,
                initialSpringVelocity: 0.7,
