Creates rectangles, triangles and ovals

CAShapeLayer Shapes.swift

extension CAShapeLayer {
    static func rectangle(roundedRect: CGRect, cornorRadius: CGFloat, color: UIColor) -> CAShapeLayer {
        let path = UIBezierPath(roundedRect: roundedRect, cornerRadius: cornorRadius)
        let shape = CAShapeLayer()
        shape.path = path.cgPath
        shape.fillColor = color.cgColor 
        return shape
    }
}

// Secondly, in order to display the rectangle in a UIView instance, it is necessary to write another extension of UIView.

extension UIView {
    func draw(_ shapes: CAShapeLayer...) {
        for shape in shapes {
            layer.addSublayer(shape)
        }
    }
}

// Then, let’s put them together and see the outcome.

let containFrame = CGRect(x: 0, y: 0, width: 500, height: 500)
let containView = UIView(frame: containFrame)
containView.backgroundColor = .white
let roundedRect = containFrame.insetBy(dx: 100, dy: 100)

containView.draw(
    .rectangle(roundedRect: roundedRect, cornorRadius: 16, color: .red)
)

// Now, we are able to create ovals, triangles, and lines with the same pattern.Add the following code into the extension of CAShapeLayer.


extension CAShapeLayer {
    // ...    
    
    static func oval(in rect: CGRect, color: UIColor) -> CAShapeLayer {
        let path = UIBezierPath(ovalIn: rect)
        let shape = CAShapeLayer()
        shape.path = path.cgPath
        shape.fillColor = color.cgColor        
        return shape
    }    
    
    static func triangle(_ point1: CGPoint, _ point2: CGPoint, _ point3: CGPoint, color: UIColor) -> CAShapeLayer {
        let path = UIBezierPath()
        path.move(to: point1)
        path.addLine(to: point2)
        path.addLine(to: point3)
        path.close()        
        let shape = CAShapeLayer()
        shape.path = path.cgPath
        shape.fillColor = color.cgColor        
        return shape
    }    
    
    static func line(start: CGPoint, end: CGPoint, width: CGFloat, color: UIColor) -> CAShapeLayer {
        let path = UIBezierPath()
        path.move(to: start)
        path.addLine(to: end)        
        let shape = CAShapeLayer()
        shape.path = path.cgPath
        shape.lineWidth = width
        shape.strokeColor = color.cgColor        
        return shape
    }
}

// Finally, the drawing code will look like this.

containView.draw(
    .rectangle(roundedRect: roundedRect, cornorRadius: 16, color: .red),
    .oval(in: roundedRect.insetBy(dx: 20, dy: 30), color: .blue),
    .triangle(CGPoint(x: 10, y: 10), CGPoint(x: 10, y: 150), CGPoint(x: 150, y: 10), color: .brown),
    .line(start: CGPoint(x: 480, y: 10), end: CGPoint(x: 480, y: 300), width: 6, color: .green)
)