@IBDesignable extension UIView {

    /* The color of the shadow. Defaults to opaque black. Colors created
     * from patterns are currently NOT supported. Animatable. */
    @IBInspectable var shadowColor: UIColor? {
        set {
            layer.shadowColor = newValue!.cgColor
        }
        get {
            if let color = layer.shadowColor {
                return UIColor(cgColor:color)
            }
            else {
                return nil
            }
        }
    }

    /* The opacity of the shadow. Defaults to 0. Specifying a value outside the
     * [0,1] range will give undefined results. Animatable. */
    @IBInspectable var shadowOpacity: Float {
        set {
            layer.shadowOpacity = newValue
        }
        get {
            return layer.shadowOpacity
        }
    }

    /* The shadow offset. Defaults to (0, -3). Animatable. */
    @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)
        }
    }

    /* The blur radius used to create the shadow. Defaults to 3. Animatable. */
    @IBInspectable var shadowRadius: CGFloat {
        set {
            layer.shadowRadius = newValue
        }
        get {
            return layer.shadowRadius
        }
    }

    func addDropShadowToView() {
        layer.masksToBounds = false
        layer.shadowColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.25).cgColor
        layer.shadowOffset = CGSize(width: 2.5, height: 3.3)
        layer.shadowRadius = 3.3
        layer.shadowOpacity = 1.0
    }

}