UIView shadows in Interface Builder

UIView.swift

import UIKit

extension UIView {
    @IBInspectable var shadowColor: UIColor? {
        set {
            layer.shadowColor = newValue?.cgColor
        }
        get {
            if let color = layer.shadowColor {
                return UIColor(cgColor: color)
            }
            else {
                return nil
            }
        }
    }

    @IBInspectable var shadowOpacity: Float {
        set {
            layer.shadowOpacity = newValue
        }
        get {
            return layer.shadowOpacity
        }
    }

    @IBInspectable var shadowOffset: CGPoint {
        set {
            layer.shadowOffset = CGSize(width: newValue.x, height: newValue.y)
        }
        get {
            return CGPoint(x: layer.shadowOffset.width, y:layer.shadowOffset.height)
        }
    }

    @IBInspectable var shadowRadius: CGFloat {
        set {
            layer.shadowRadius = newValue
        }
        get {
            return layer.shadowRadius
        }
    }
}