Current location experiment

currentLocation.swift

//
//  ViewController.swift
//  CurrentLocation
//
//  Created by Jonathan Dalrymple on 13/05/2017.
//  Copyright © 2017 float-right. All rights reserved.
//

import UIKit
import GoogleMaps

class CurrentLocationView: UIView {
    
    private class CircularView: UIView {
        override class var layerClass: AnyClass {
            return CAShapeLayer.self
        }
        
        private var shapeLayer: CAShapeLayer? {
            get {
                if let shape = self.layer as? CAShapeLayer {
                    return shape
                }
                return nil
            }
        }
        
        override init(frame: CGRect) {
            super.init(frame: frame)
            
            super.backgroundColor = .clear
        }
        
        required init?(coder aDecoder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
        
        override func layoutSubviews() {
            super.layoutSubviews()
    
            let path = UIBezierPath(roundedRect: self.bounds,
                                    cornerRadius: self.bounds.width * 0.5).cgPath
            
            self.shapeLayer?.path = path
        }
        
        override var backgroundColor: UIColor? {
            set (newValue){
                self.shapeLayer?.fillColor = newValue?.cgColor
            }
            get {
                if let color = self.layer.backgroundColor {
                    return UIColor(cgColor: color)
                }
                return nil
            }
        }
    }
    
    private let baseView = CircularView()
    private let dotView = CircularView()
    private let rangeView = CircularView()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
    
        self.addSubview(self.rangeView)
        self.addSubview(self.baseView)
        self.addSubview(self.dotView)
        
        self.rangeView.backgroundColor = UIColor.blue.withAlphaComponent(0.25)
        self.baseView.backgroundColor = .white
        self.dotView.backgroundColor = .blue
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        self.rangeView.bounds = self.bounds
        self.rangeView.center = self.center
        self.baseView.bounds = CGRect(x: 0, y: 0, width: 32, height: 32)
        self.baseView.center = self.center
        self.dotView.bounds = CGRect(x: 0, y: 0, width: 20, height: 20)
        self.dotView.center = self.center
    }
    
    func startAnimating() {
        
        let dotPulse = CABasicAnimation(keyPath: "transform")
        dotPulse.byValue = CATransform3DMakeScale(0.8, 0.8, 1)
        dotPulse.duration = 1.25
        dotPulse.repeatCount = .infinity
        dotPulse.autoreverses = true
        self.dotView.layer.add(dotPulse, forKey: "pulsate")
        
        let rangePulse = CABasicAnimation(keyPath: "transform")
        rangePulse.fromValue = CATransform3DMakeScale(0.1, 0.1, 1)
        rangePulse.duration = 2.5
        rangePulse.repeatCount = .infinity
        self.rangeView.layer.add(rangePulse, forKey: "pulsate")
        
        let fadeOut = CABasicAnimation(keyPath: "opacity")
        fadeOut.toValue = 0.0
        fadeOut.duration = 2.5
        fadeOut.repeatCount = .infinity
        self.rangeView.layer.add(fadeOut, forKey: "fadeOut")
        
    }
}

class ViewController: UIViewController, GMSMapViewDelegate {

    lazy var mapView: GMSMapView = {
        let view = GMSMapView()
        view.delegate = self
        return view
    }()
    
    lazy var currentLocationMarker: GMSMarker = {
        let marker = GMSMarker(position: CLLocationCoordinate2D(latitude: 0, longitude: 0))
        let annotationView = CurrentLocationView(frame: CGRect(x: 0, y: 0, width: 320, height: 320))
        
        marker.groundAnchor = CGPoint(x: 0.5, y: 0.5)
        marker.iconView = annotationView
        return marker
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        GMSServices.provideAPIKey("INSERT YOUR GMS API KEY")
        
        self.view.addSubview(self.mapView)
        
        let location = CLLocationCoordinate2D(latitude: 51, longitude: 0)
        
        self.currentLocationMarker.position = location
        self.currentLocationMarker.map = self.mapView
    }
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        
        self.mapView.frame = self.view.bounds
    }
    
    func mapViewSnapshotReady(_ mapView: GMSMapView) {
        
        if let v = self.currentLocationMarker.iconView as? CurrentLocationView {
            v.startAnimating()
        }
    }
}