Adicione o rastreamento de localização da Amazon ao seu aplicativo

Adicione o TrackingBottomView.swift arquivo ao seu projeto. Que tem um botão que inicia e para de rastrear a localização dos usuários e mostra os pontos de rastreamento no mapa.

import SwiftUI

struct TrackingBottomView: View {
    @ObservedObject var trackingViewModel: TrackingViewModel
    var body: some View {
           Button(action: {
               Task {
                   if(trackingViewModel.trackingButtonText == NSLocalizedString("StartTrackingLabel", comment: "")) {
                       trackingViewModel.startTracking()
                   } else {
                       trackingViewModel.stopTracking()
                   }
               }
           }) {
               HStack {
                   Spacer()
                   Text("Tracking")
                       .foregroundColor(trackingViewModel.trackingButtonColor)
                       .background(.white)
                       .cornerRadius(15.0)
                   
                   Image(systemName: trackingViewModel.trackingButtonIcon)
                       .resizable()
                       .frame(width: 24, height: 24)
                       .padding(5)
                       .background(.white)
                       .foregroundColor(trackingViewModel.trackingButtonColor)

               }
           }
           .accessibility(identifier: "TrackingButton")
           .background(.white)
           .clipShape(RoundedRectangle(cornerRadius: 8))
           .padding(.trailing, 10)
           .padding(.bottom, 40)
           .frame(width: 130, alignment: .trailing)
           .shadow(color: Color.black.opacity(0.3), radius: 3, x: 0, y: 2)
       }
}

Atualize TrackingView.swift o arquivo com o seguinte código

import SwiftUI

struct TrackingView: View {
    @ObservedObject var trackingViewModel: TrackingViewModel
    var body: some View {
        ZStack(alignment: .bottom) {
            if trackingViewModel.mapSigningIntialised {
                MapView(trackingViewModel: trackingViewModel)
                VStack {
                    UserLocationView(trackingViewModel: trackingViewModel)
                    CenterAddressView(trackingViewModel: trackingViewModel)
                    TrackingBottomView(trackingViewModel: trackingViewModel)
                }
            }
            else {
                Text("Loading...") 
            }
        }
        .onAppear() {
            if !trackingViewModel.identityPoolId.isEmpty {
                Task {
                    do {
                        try await trackingViewModel.authWithCognito(identityPoolId: trackingViewModel.identityPoolId)
                    }
                    catch {
                        print(error)
                    }
                }
            }
        }
    }
}

Adicione o código a seguir no TrackingViewModel.swift arquivo. Essas funções são responsáveis por iniciar e interromper o rastreamento. Também mostrará um alerta de erro se a permissão de localização do usuário for negada.

Para implementar o rastreamento em primeiro plano, copie e cole o seguinte exemplo de código:

func showLocationDeniedRationale() {
        alertTitle = NSLocalizedString("locationManagerAlertTitle", comment: "")
        alertMessage = NSLocalizedString("locationManagerAlertText", comment: "")
        showAlert = true
    }
    
    // Required in info.plist: Privacy - Location When In Use Usage Description
    func startTracking() {
        do {
            print("Tracking Started...")
            if(client == nil) {
                initializeClient()
            }
            try client.startTracking()
            DispatchQueue.main.async { [self] in
                self.trackingButtonText = NSLocalizedString("StopTrackingLabel", comment: "")
                self.trackingButtonColor = .red
                self.trackingButtonIcon = "pause.circle"
                trackingActive = true
            }
        } catch TrackingLocationError.permissionDenied {
            showLocationDeniedRationale()
        } catch {
            print("error in tracking")
        }
    }
    
    func stopTracking() {
        print("Tracking Stopped...")
        client.stopTracking()
        trackingButtonText = NSLocalizedString("StartTrackingLabel", comment: "")
        trackingButtonColor = .blue
        trackingButtonIcon = "play.circle"
        trackingActive = false
    }

Para obter os locais do dispositivo do usuário, você precisa fornecer a data e a hora de início e término. Uma única chamada retorna no máximo 100 locais de rastreamento, mas se houver mais de 100 locais de rastreamento, ela retornará um valor nextToken ``. Você precisará chamar chamadas subsequentes de `getTrackerDeviceLocation` com` nextToken `para carregar mais pontos de rastreamento para o horário de início e término determinado.

 func getTrackingPoints(nextToken: String? = nil) async throws {
        guard trackingActive else {
            return
        }
        // Initialize startTime to 24 hours ago from the current date and time.
        let startTime: Date = Date().addingTimeInterval(-86400)
        var endTime: Date = Date()
        if lastGetTrackingTime != nil {
            endTime = lastGetTrackingTime!
        }
        let result = try await client?.getTrackerDeviceLocation(nextToken: nextToken, startTime: startTime, endTime: endTime)
        if let trackingData = result {
            
            lastGetTrackingTime = Date()
            let devicePositions = trackingData.devicePositions

            let positions = devicePositions!.sorted { (pos1: LocationClientTypes.DevicePosition, pos2: LocationClientTypes.DevicePosition) -> Bool in
                guard let date1 = pos1.sampleTime,
                      let date2 = pos2.sampleTime else {
                    return false
                }
                return date1 < date2
            }

            let trackingPoints = positions.compactMap { position -> CLLocationCoordinate2D? in
                guard let latitude = position.position!.last, let longitude = position.position!.first else {
                    return nil
                }
                return CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
            }
            DispatchQueue.main.async {
                self.mapViewDelegate!.drawTrackingPoints( trackingPoints: trackingPoints)
            }
            if let nextToken = trackingData.nextToken {
                try await getTrackingPoints(nextToken: nextToken)
            }
        }
    }

Agora, substitua o código no MapView.swift arquivo pelo seguinte código:

import SwiftUI
import MapLibre

struct MapView: UIViewRepresentable {
    var onMapViewAvailable: ((MLNMapView) -> Void)?
    var mlnMapView: MLNMapView?
    var trackingViewModel: TrackingViewModel
    
    func makeCoordinator() -> MapView.Coordinator {
        return Coordinator(self, trackingViewModel: trackingViewModel)
    }
    
    func makeUIView(context: Context) -> MLNMapView {
        let styleURL = URL(string: "https://maps.geo.\(trackingViewModel.region).amazonaws.com/maps/v0/maps/\(trackingViewModel.mapName)/style-descriptor")
        let mapView = MLNMapView(frame: .zero, styleURL: styleURL)
        mapView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        mapView.setZoomLevel(15, animated: true)
        mapView.showsUserLocation = true
        mapView.userTrackingMode = .follow
        context.coordinator.mlnMapView = mapView
        mapView.delegate = context.coordinator

        mapView.logoView.isHidden = true
        context.coordinator.addCenterMarker()
        
        onMapViewAvailable?(mapView)
        trackingViewModel.mlnMapView = mapView
        return mapView
    }
    
    func updateUIView(_ uiView: MLNMapView, context: Context) {
    }
    
    class Coordinator: NSObject, MLNMapViewDelegate, MapViewDelegate {
        var control: MapView
        var mlnMapView: MLNMapView?
        var trackingViewModel: TrackingViewModel
        var centerMarker: MLNPointAnnotation?
        
        public init(_ control: MapView, trackingViewModel: TrackingViewModel) {
            self.control = control
            self.trackingViewModel = trackingViewModel
            super.init()
            self.trackingViewModel.mapViewDelegate = self
        }

        func mapViewDidFinishRenderingMap(_ mapView: MLNMapView, fullyRendered: Bool) {
            if(fullyRendered) {
                mapView.accessibilityIdentifier = "MapView"
                mapView.isAccessibilityElement = false
            }
        }
        
        func addCenterMarker() {
            guard let mlnMapView = mlnMapView else {
                return
            }

            let centerCoordinate = mlnMapView.centerCoordinate
            let marker = MLNPointAnnotation()
            marker.coordinate = centerCoordinate
            marker.accessibilityLabel = "CenterMarker"
            mlnMapView.addAnnotation(marker)
            centerMarker = marker

            trackingViewModel.reverseGeocodeCenter(centerCoordinate: centerCoordinate, marker: marker)
        }
        
        func mapView(_ mapView: MLNMapView, regionDidChangeAnimated animated: Bool) {
            if let marker = centerMarker {
                DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
                    mapView.deselectAnnotation(marker, animated: false)
                    marker.coordinate = mapView.centerCoordinate
                    let centerCoordinate = mapView.centerCoordinate
                    self.trackingViewModel.reverseGeocodeCenter(centerCoordinate: centerCoordinate, marker: marker)
                }
            }
        }
        
        func mapView(_ mapView: MLNMapView, viewFor annotation: MLNAnnotation) -> MLNAnnotationView? {
            guard let pointAnnotation = annotation as? MLNPointAnnotation else {
                return nil
            }

            let reuseIdentifier: String
            var color: UIColor = .black
            if pointAnnotation.accessibilityLabel == "Tracking" {
                reuseIdentifier = "TrackingAnnotation"
                color = UIColor(red: 0.00784313725, green: 0.50588235294, blue: 0.58039215686, alpha: 1)
            } else if pointAnnotation.accessibilityLabel == "LocationChange" {
                reuseIdentifier = "LocationChange"
                color = .gray
            } else {
                reuseIdentifier = "DefaultAnnotationView"
            }

            var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: reuseIdentifier)

            if annotationView == nil {
                if reuseIdentifier != "DefaultAnnotationView" {
                    annotationView = MLNAnnotationView(annotation: annotation, reuseIdentifier: reuseIdentifier)
                    //If point annotation is an uploaded Tracking point the radius is 20 and color is blue, otherwise radius is 10 and color is gray
                    let radius = pointAnnotation.accessibilityLabel == "Tracking" ? 20:10
                    annotationView?.frame = CGRect(x: 0, y: 0, width: radius, height: radius)
                    annotationView?.backgroundColor = color
                    annotationView?.layer.cornerRadius = 10
                    
                    if pointAnnotation.accessibilityLabel == "Tracking" {
                        annotationView?.layer.borderColor = UIColor.white.cgColor
                        annotationView?.layer.borderWidth = 2.0
                        annotationView?.layer.shadowColor = UIColor.black.cgColor
                        annotationView?.layer.shadowOffset = CGSize(width: 0, height: 2)
                        annotationView?.layer.shadowRadius = 3
                        annotationView?.layer.shadowOpacity = 0.2
                        annotationView?.clipsToBounds = false
                    }
                }
                else {
                    return nil
                }
            }

            return annotationView
        }
        
        func mapView(_ mapView: MLNMapView, didUpdate userLocation: MLNUserLocation?) {
            if (userLocation?.location) != nil {
                if trackingViewModel.trackingActive {
                    let point = MLNPointAnnotation()
                    point.coordinate = (userLocation?.location!.coordinate)!
                    point.accessibilityLabel = "LocationChange"
                    mapView.addAnnotation(point)
                    Task {
                        do {
                            try await trackingViewModel.getTrackingPoints()
                        }
                        catch {
                            print(error)
                        }
                    }
                }
            }
        }
        
        func checkIfTrackingAnnotationExists(on mapView: MLNMapView, at coordinates: CLLocationCoordinate2D) -> Bool {
            let existingAnnotation = mapView.annotations?.first(where: { annotation in
                guard let annotation = annotation as? MLNPointAnnotation else { return false }
                return annotation.coordinate.latitude == coordinates.latitude &&
                annotation.coordinate.longitude == coordinates.longitude && annotation.accessibilityLabel == "Tracking" })
            return existingAnnotation != nil
        }
        
        public func drawTrackingPoints(trackingPoints: [CLLocationCoordinate2D]?) {
            guard let mapView = mlnMapView, let newTrackingPoints = trackingPoints, !newTrackingPoints.isEmpty else {
                return
            }

            let uniqueCoordinates = newTrackingPoints.filter { coordinate in
                !checkIfTrackingAnnotationExists(on: mapView, at: coordinate)
            }

            let points = uniqueCoordinates.map { coordinate -> MLNPointAnnotation in
                let point = MLNPointAnnotation()
                point.coordinate = coordinate
                point.accessibilityLabel = "Tracking"
                return point
            }
            mapView.addAnnotations(points)
        }
    }
}

protocol MapViewDelegate: AnyObject {
    func drawTrackingPoints(trackingPoints: [CLLocationCoordinate2D]?)
}

Crie e adicione um novo arquivo chamadoLocalizable.xcstrings.

Clique com o botão direito do mouse no Localizable.xcstrings arquivo e abra-o como código-fonte.

Substitua seu conteúdo pelo seguinte:

{
  "sourceLanguage" : "en",
  "strings" : {
    "Cancel" : {
      "extractionState" : "manual",
      "localizations" : {
        "en" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "Cancel"
          }
        }
      }
    },
    "Error" : {
      "extractionState" : "manual",
      "localizations" : {
        "en" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "Error"
          }
        }
      }
    },
    "Loading..." : {

    },
    "locationManagerAlertText" : {
      "extractionState" : "manual",
      "localizations" : {
        "en" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "Allow \\\"Quick Start App\\\" to use your location"
          }
        }
      }
    },
    "locationManagerAlertTitle" : {
      "extractionState" : "manual",
      "localizations" : {
        "en" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "We need your location to detect your location in map"
          }
        }
      }
    },
    "NotAllFieldsAreConfigured" : {
      "extractionState" : "manual",
      "localizations" : {
        "en" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "Not all the fields are configured"
          }
        }
      }
    },
    "OK" : {
      "extractionState" : "manual",
      "localizations" : {
        "en" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "OK"
          }
        }
      }
    },
    "StartTrackingLabel" : {
      "localizations" : {
        "en" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "Start Tracking"
          }
        }
      }
    },
    "StopTrackingLabel" : {
      "localizations" : {
        "en" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "Stop Tracking"
          }
        }
      }
    },
    "Tracking" : {

    }
  },
  "version" : "1.0"
}

Salve seus arquivos, crie e execute seu aplicativo para visualizar a funcionalidade.

Permita a permissão de localização e toque no botão de rastreamento. O aplicativo começará a carregar as localizações dos usuários e enviá-las para o rastreador de localização da Amazon. Ele também mostrará alterações na localização do usuário, pontos de rastreamento e endereço atual no mapa.