Striped gradient view

Stripedgradientview.playground

//: A UIKit based Playground for presenting user interface
  
import UIKit
import PlaygroundSupport

final class StripedGradientView: UIView {

    @available(*, unavailable, message: "This property is reserved for Interface Builder. Use 'direction' instead.")
    @IBInspectable var directionName: String? {
        willSet {
            if let newDirection = Direction(rawValue: newValue ?? "") {
                self.direction = newDirection
            }
        }
    }
    
    var direction: Direction = .topBottom
    
    override func draw(_ rect: CGRect) {
        
        let thickness: CGFloat = 16
        let gap: CGFloat = 8
        let width = rect.size.width
        let height = rect.size.height
        
        guard let context = UIGraphicsGetCurrentContext() else { return }
        context.setStrokeColor(UIColor.white.withAlphaComponent(0.5).cgColor)
        context.setLineWidth(thickness)
        
        var p = -(width > height ? width : height) - thickness
        
        
        while p <= width {
            print(p)
            let startPointX = direction == .topBottom ? p + thickness + height : p - thickness
            let endPointX = direction == .topBottom ? p - thickness : p + thickness + height
            
            context.move( to: CGPoint(x: startPointX , y: -thickness) )
            context.addLine( to: CGPoint(x: endPointX, y: thickness + height) )

            context.strokePath()
            p += gap + thickness * 2
        }
        
        let gradient = CAGradientLayer()

        gradient.frame = bounds
        gradient.colors = [UIColor.black.cgColor,
                           UIColor.clear.cgColor]
        layer.mask = gradient
    }
    
    enum Direction: String {
        case bottomTop, topBottom
    }
}


class MyViewController : UIViewController {
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        let stripedView = StripedGradientView()
        stripedView.frame = CGRect(x: 150, y: 200, width: 100, height: 200)
        
        view.addSubview(stripedView)

        self.view = view
    }
    

}
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()