Google map circle In Out animation

ViewController.swift

//
//  ViewController.swift
//  GoogleMapPinDropAnimation
//
//  Created by Jecky Modi on 27/10/19.
//  Copyright © 2019 Jecky Modi. All rights reserved.
//

import UIKit
import GoogleMaps

enum CircleAnimation{
    case In
    case Out
}

class ViewController: UIViewController {
    
    @IBOutlet weak var mapView: GMSMapView!
    var circleAnimation = CircleAnimation.Out
    var arrRadius : [GMSCircle] = [GMSCircle]()
    var radius : Int = 0
    var timer : Timer = Timer()
    let location = CLLocationCoordinate2D(latitude: -33.86, longitude: 151.20)

    override func viewDidLoad() {
        super.viewDidLoad()
        
        let camera = GMSCameraPosition.camera(withLatitude: -33.86, longitude: 151.20, zoom: 6.0)
        mapView.camera = camera
        
        let marker = GMSMarker()
        marker.position = location
        marker.title = "Sydney"
        marker.icon = UIImage(named: "pin")
        marker.snippet = "Australia"
        marker.map = mapView
        
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
            self.timer = Timer.scheduledTimer(timeInterval: 0.001, target: self, selector: #selector(self.timerFired), userInfo: nil, repeats: true)
        }
        
        let circleCenter = location//change to your center point
        let circ = GMSCircle(position: circleCenter, radius: 5000)//radius in meters
        
        circ.fillColor = UIColor(red: 0.35, green: 0, blue: 0, alpha: 0.05)
        circ.strokeColor = UIColor.red
        circ.strokeWidth = 1
        
        let update = GMSCameraUpdate.fit(circ.bounds())
        mapView.animate(with: update)
    }
    
    @objc func timerFired(){
        
        let circleCenter = location//change to your center point
        let circ = GMSCircle(position: circleCenter, radius: CLLocationDistance(radius))//radius in meters
        
        circ.fillColor = UIColor(red: 0.35, green: 0, blue: 0, alpha: 0.05)
        circ.strokeColor = UIColor.red
        circ.strokeWidth = 1
        
        if circleAnimation == .Out{
            radius += 50
            
            if radius >= 5000{
                radius = 5000
                circleAnimation = .In
            }
        }else{
            radius -= 50

            if radius <= 0{
                radius = 0
                circleAnimation = .Out
            }
        }
        
        arrRadius.append(circ)
        circ.map = mapView
        
        if arrRadius.count > 0{
            for i in 0..<arrRadius.count - 1{
                let circle = arrRadius[i]
                circle.map = nil
                arrRadius.removeAll(where: { $0 == circle})
            }
        }
    }
}


extension GMSCircle {
    func bounds () -> GMSCoordinateBounds {
        func locationMinMax(_ positive : Bool) -> CLLocationCoordinate2D {
            let sign: Double = positive ? 1 : -1
            let dx = sign * self.radius  / 6378000 * (180 / .pi)
            let lat = position.latitude + dx
            let lon = position.longitude + dx / cos(position.latitude * .pi / 180)
            return CLLocationCoordinate2D(latitude: lat, longitude: lon)
        }
        
        return GMSCoordinateBounds(coordinate: locationMinMax(true),
                                   coordinate: locationMinMax(false))
    }
}