ThumbView

ThumbView.swift

// Step 4
final class ThumbView: UIView {
 
    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }
 
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setup()
    }
 
    private func setup() {
        backgroundColor = UIColor(red: 183 / 255, green: 122 / 255, blue: 231 / 255, alpha: 1)
        let middleView = UIView(frame: .init(x: frame.midX - 6, 
                                             y: frame.midY - 6, 
                                             width: 12, 
                                             height: 12))
        middleView.backgroundColor = .white
        middleView.layer.cornerRadius = 6
        addSubview(middleView)
    }
}