iOS: TextView with placeholder text

class TextViewWithPlaceholder: UITextView {

    

    private var _placeholderTextColor: UIColor = UIColor.lightGray

    @IBInspectable var placeholderTextColor: UIColor {

        set {

            _placeholderTextColor = newValue

            textColor = newValue

        }

        get {

            return _placeholderTextColor

        }

    }

    @IBInspectable var placeholderText: String? {

        didSet {

            if text.isEmpty {

                text = placeholderText

            }

        }

    }

    

    private var initialTextColor: UIColor?

    

    override init(frame: CGRect, textContainer: NSTextContainer?) {

        super.init(frame: frame, textContainer: textContainer)

        

        commonInit()

    }

    

    required init?(coder aDecoder: NSCoder) {

        super.init(coder: aDecoder)

        

        commonInit()

    }

    

    private func commonInit() {

        

        initialTextColor = textColor

        

        text = placeholderText

        

        NotificationCenter.default.addObserver(self, selector: #selector(didBeginEditing(_:)), name: UITextView.textDidBeginEditingNotification, object: self)

        NotificationCenter.default.addObserver(self, selector: #selector(didEndEditing(_:)), name: UITextView.textDidEndEditingNotification, object: self)

    }

    

    deinit {

        NotificationCenter.default.removeObserver(self)

    }

    

    @objc func didBeginEditing(_ notification: NSNotification) {

        

        if let textView = notification.object as? TextViewWithPlaceholder, textView == self, text == placeholderText {

            

            text = ""

            textColor = initialTextColor

        }

    }

    

    @objc func didEndEditing(_ notification: NSNotification) {

        

        if let textView = notification.object as? TextViewWithPlaceholder, textView == self, text.isEmpty {

            

            text = placeholderText

            textColor = placeholderTextColor

        }

    }

}