Radar animation

RadarView.swift

import UIKit

class RadarView: UIView {
    
    private let waveShape = CAShapeLayer()
    private let waveReplicator = CAReplicatorLayer()

    override init(frame: CGRect = .zero) {
        super.init(frame: frame)

        waveShape.fillColor = UIColor.orange.cgColor
        waveShape.opacity = 0

        let scaleAnimation = CABasicAnimation(keyPath: "transform")
        scaleAnimation.valueFunction = CAValueFunction(name: .scale)
        scaleAnimation.fromValue = [0, 0, 0]
        scaleAnimation.toValue = [2, 2, 0]

        let fadeAnimation = CABasicAnimation(keyPath: "opacity")
        fadeAnimation.fromValue = 0.6
        fadeAnimation.toValue = 0

        let waveAnimation = CAAnimationGroup()
        waveAnimation.animations = [scaleAnimation, fadeAnimation]
        waveAnimation.duration = 6
        waveAnimation.repeatCount = HUGE
        
        waveShape.add(waveAnimation, forKey: nil)

        waveReplicator.addSublayer(waveShape)
        waveReplicator.instanceCount = 4
        waveReplicator.instanceDelay = 1.5

        layer.addSublayer(waveReplicator)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        waveShape.frame = bounds
        waveShape.path = UIBezierPath(ovalIn: bounds).cgPath

        waveReplicator.frame = bounds
    }
}

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let radarView = RadarView()
        radarView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(radarView)
        NSLayoutConstraint.activate([
            radarView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            radarView.centerYAnchor.constraint(equalTo: view.bottomAnchor, constant: -32),
            radarView.widthAnchor.constraint(equalTo: view.widthAnchor),
            radarView.heightAnchor.constraint(equalTo: radarView.widthAnchor)
        ])
    }
}