Swift UIKit shadows

UIView+shadow.swift

import UIKit

extension UIView {
    @IBInspectable var dropShadow: Bool {
        set {
            layer.shadowOffset = CGSize(width: 0, height: 0)

            if newValue {
                updateShadow()
            } else {
                layer.shadowColor = UIColor.clear.cgColor
                layer.shadowOpacity = 0.0
                layer.shadowRadius = 0
                
                layer.shadowPath = nil
                layer.shouldRasterize = false
            }
        }
        get {
            layer.shadowOpacity > 0.0 && layer.shadowRadius > 0
        }
    }
    
    func updateShadow() {
        layer.shadowColor = UIColor.black.cgColor
        layer.shadowOpacity = 0.5
        layer.shadowRadius = 4
        
        layer.shadowPath = UIBezierPath(roundedRect: bounds, cornerRadius: layer.cornerRadius).cgPath
        layer.shouldRasterize = true
        layer.rasterizationScale = UIScreen.main.scale
    }
}

UIView+updateShadows.swift

import UIKit

extension UIView {
    func updateShadows() {
        if self.dropShadow {
            self.updateShadow()
        }
        subviews.forEach {
            $0.updateShadows()
        }
    }
}