建立及顯示返回行程

「返回」是專屬的獨立行程,會連續一次發生,由駕駛人在完成目前行程前領取下一個消費者的行程。

返回行程和單一目的地行程的主要差異,在於如果支援連續行程,行程業者可能會為已獲派行程的車輛指派行程。

本教學課程將逐步引導您建立連續行程。此外,應用程式也會說明如何將行程與消費者應用程式整合,讓客戶能透過手機查看行程進度。您可使用 Consumer SDK 進行這項整合。

必要條件

如要完成本教學課程,請務必完成下列步驟:

  1. 設定機群引擎。詳情請參閱「Fleet Engine:初始設定」。

  2. 將應用程式與 Driver SDK 整合。詳情請參閱 Android 適用的「初始化驅動程式 SDK」和 iOS 適用的驅動程式 SDK 整合指南

  3. 整合消費者應用程式與 Consumer SDK。詳情請參閱 Android 版「開始使用 Consumer SDK」和 iOS 版「開始使用 Consumer SDK」一文。

  4. 設定授權權杖。如要進一步瞭解授權權杖,請參閱開始使用 Fleet Engine 指南中的建立 JSON Web Token 相關說明,及 Fleet Engine 的 Consumer SDK 說明文件中的驗證與授權

步驟 1:在 Fleet Engine 中建立車輛

車輛是一種物件,代表車隊中的車輛。您必須在 Fleet Engine 中建立它們,才能在消費者應用程式中追蹤。

你可以透過下列兩種方法建立車輛:

gRPC
使用 CreateVehicleRequest 要求訊息呼叫 CreateVehicle() 方法。您必須具備 Fleet Engine 超級使用者權限才能呼叫 CreateVehicle()
REST
呼叫 https://fleetengine.googleapis.com/v1/providers.vehicles.create

注意事項

建立車輛時請留意下列注意事項。

  • 請務必將初始車輛狀態設為 OFFLINE。確保 Fleet Engine 可以找到你的車輛,以便進行行程比對。

  • 這輛車的 provider_id 必須與包含用來呼叫機群引擎的服務帳戶的 Google Cloud 專案 ID 相同。雖然多個服務帳戶可以存取同一個共乘供應商的 Fleet Engine,但 Fleet Engine 目前不支援來自存取相同車輛的不同 Google Cloud 專案的服務帳戶。

  • CreateVehicle() 傳回的回應包含 Vehicle 例項。如果執行個體未使用 UpdateVehicle() 更新,則系統會在七天後刪除該執行個體。您應先呼叫 GetVehicle() 再呼叫 CreateVehicle(),藉此確認車輛不存在。如果 GetVehicle() 傳回 NOT_FOUND 錯誤,則應繼續呼叫 CreateVehicle()。詳情請參閱「車輛及其生命週期」一文。

範例

以下供應商程式碼範例示範如何在 Fleet Engine 中建立車輛。

static final String PROJECT_ID = "my-rideshare-co-gcp-project";

VehicleServiceBlockingStub vehicleService = VehicleService.newBlockingStub(channel);

String parent = "providers/" + PROJECT_ID;

Vehicle vehicle = Vehicle.newBuilder()
    .setVehicleState(VehicleState.OFFLINE)  // Initial state
    .addSupportedTripTypes(TripType.EXCLUSIVE)
    .setMaximumCapacity(4)
    .setVehicleType(VehicleType.newBuilder().setCategory(VehicleType.Category.AUTO))
    .build();

CreateVehicleRequest createVehicleRequest = CreateVehicleRequest.newBuilder()
    .setParent(parent)
    .setVehicleId("8241890")  // Vehicle ID assigned by solution provider.
    .setVehicle(vehicle)      // Initial state.
    .build();

// The Vehicle is created in the OFFLINE state, and no initial position is
// provided.  When the driver app calls the rideshare provider, the state can be
// set to ONLINE, and the driver app updates the vehicle location.
try {
  Vehicle createdVehicle = vehicleService.createVehicle(createVehicleRequest);
} catch (StatusRuntimeException e) {
  Status s = e.getStatus();
  switch (s.getCode()) {
    case ALREADY_EXISTS:
      break;
    case PERMISSION_DENIED:
      break;
  }
  return;
}

如要建立支援返回行程的 Vehicle,必須在傳遞至 CreateVehicleRequestVehicle 物件中,將 backToBackEnabled 欄位設為 true

Vehicle vehicle = Vehicle.newBuilder()
    .setVehicleState(VehicleState.OFFLINE)
    .addSupportedTripTypes(TripType.EXCLUSIVE)
    .setMaximumCapacity(4)
    .setVehicleType(VehicleType.newBuilder().setCategory(VehicleType.Category.AUTO))
    .setBackToBackEnabled(true) // Set as 'true' so vehicle can be assigned back-to-back trips.
    .build();

步驟 2:啟用位置追蹤功能

位置追蹤是指在行程期間追蹤車輛位置,駕駛應用程式將遙測資料傳送至 Fleet Engine,其中包含車輛目前位置。系統會使用這類持續更新的位置資訊串流,傳送沿途的車輛進度。位置追蹤功能啟用後,驅動程式應用程式會開始傳送此遙測資料,預設頻率為每五秒一次。

您可依下列方式啟用 Android 和 iOS 的位置追蹤功能:

範例

以下程式碼範例示範如何啟用位置追蹤功能。

Java

RidesharingVehicleReporter vehicleReporter = ...;

vehicleReporter.enableLocationTracking();

Kotlin

val vehicleReporter = ...

vehicleReporter.enableLocationTracking()

Swift

vehicleReporter.locationTrackingEnabled = true

Objective-C

_vehicleReporter.locationTrackingEnabled = YES;

步驟 3:將車輛的狀態設為「線上」

您可以將車輛的狀態設為 online,藉此讓車輛進入服務 (也就是讓車輛可以使用),但必須先啟用位置追蹤功能,才能執行這項操作。

您可以針對 Android 和 iOS 裝置將車輛狀態設為線上狀態,方法如下:

範例

以下程式碼範例說明如何將車輛的狀態設為 ONLINE

Java

vehicleReporter.setVehicleState(VehicleState.ONLINE);

Kotlin

vehicleReporter.setVehicleState(VehicleState.ONLINE)

Swift

vehicleReporter.update(.online)

Objective-C

[_vehicleReporter updateVehicleState:GMTDVehicleStateOnline];

步驟 4:在 Fleet Engine 中建立行程

如要建立連續行程,請按照單一目的地行程建立 Trip 物件。

行程是一個代表旅程的物件,為集合地理座標點,包括起點、路線控點和下車點。您必須為每個行程要求建立一個 Trip 物件,這樣系統才能比對要求和車輛,然後追蹤要求。

提供必要屬性

如要建立來回行程,您必須提供下列欄位:

parent
包含提供者 ID 的字串。此 ID 必須與包含用於呼叫 Fleet Engine 的服務帳戶的 Google Cloud 專案 ID 相同
trip_id
你建立的字串,專門用來識別這個行程。
trip
要建立的 Trip 個物件。

您必須在傳遞至 CreateTripRequestTrip 物件中設定下列欄位:

trip_type
TripType.EXCLUSIVE
pickup_point
行程的起點,
dropoff_point
行程的下車地點,建立行程時不需要這個欄位,之後可透過呼叫 UpdateTrip 進行設定。

範例

以下後端整合範例示範如何建立行程,並將其指派給車輛。

// A vehicle with ID 'my-vehicle' is already created and it is assigned to a trip with ID 'current-trip'.

static final String PROJECT_ID = "my-rideshare-co-gcp-project";
static final String VEHICLE_ID =" my-vehicle";
static final String TRIP_ID = "back-to-back-trip");

TripServiceBlockingStub tripService = TripService.newBlockingStub(channel);

String parent = "providers/" + PROJECT_ID;

Trip trip = Trip.newBuilder()
    .setTripType(TripType.EXCLUSIVE)
    .setPickupPoint(
        TerminalLocation.newBuilder().setPoint(
            LatLng.newBuilder()
                .setLatitude(-6.195139).setLongitude(106.820826)))
    .setDropoffPoint(
        TerminalLocation.newBuilder().setPoint(
            LatLng.newBuilder()
                .setLatitude(-6.1275).setLongitude(106.6537)))
    .setVehicleId(VEHICLE_ID)
    .build();

// Create trip request
CreateTripRequest createTripRequest = CreateTripRequest.newBuilder()
    .setParent(parent)
    .setTripId(TRIP_ID)
    .setTrip(trip)
    .build();

// Error handling.
try {
  // Fleet Engine automatically assigns a 'waypoints' list to the trip containing
  // the vehicle's current trip waypoints.
  Trip createdTrip =
      tripService.createTrip(createTripRequest);
} catch (StatusRuntimeException e) {
  Status s = e.getStatus();
  switch (s.getCode()) {
    case ALREADY_EXISTS:
      break;
    case PERMISSION_DENIED:
      break;
  }
  return;
}

步驟 5:使用車輛 ID 和路線控點更新行程

您必須使用車輛 ID 設定行程,Fleet Engine 才能沿路線追蹤車輛。為了連續返回,即使車輛已獲指派,系統仍會將行程指派給車輛。

將行程指派給車輛後,Fleet Engine 就會自動將返回的行程相關路線點新增至車輛的路線控點欄位。行程的 remainingWaypoints 欄位內含所有路線控點的清單,包括在行程下車之前造訪的並行行程。

舉例來說,假設有兩趟往回旅程:行程 A行程 B。車輛已叫車「行程 A」,而在前往下車地點的途中,駕駛人會收到下一次行程取貨要求 (行程 B)。

  • 呼叫 getVehicle() 會傳回其他路線控點 (remainingWaypoints) 清單,其中包含
    下車地點B 取貨B 下車地點
  • 行程 AgetTrip()onTripRemainingWaypointsUpdated 回呼會傳回包含下車地點的剩餘路線控點 (remainingWaypoints) 清單。
  • 行程 BgetTrip()onTripRemainingWaypointsUpdated 回呼會傳回包含下車地點B 取貨 → 和 B 下車地點的剩餘路線控點清單 (remainingWaypoints)。

步驟 6:在消費者應用程式中監聽行程更新

  • 針對 Android,您可以從 TripModelManager 取得 TripModel 物件,並註冊 TripModelCallback 事件監聽器,藉此監聽行程的資料更新。

  • 針對 iOS,您可以從 GMTCTripService 取得 GMTCTripModel 物件,並註冊 GMTCTripModelSubscriber 訂閱者,藉此監聽行程中的資料更新。

TripModelCallback 事件監聽器和 GMTCTripModelSubscriber 訂閱者可讓應用程式根據自動重新整理時間間隔,定期接收行程進度更新。只有變更的值才能觸發回呼。否則回呼會保持靜音。

無論資料變更為何,系統一律會呼叫 TripModelCallback.onTripUpdated()tripModel(_:didUpdate:updatedPropertyFields:) 方法。

範例 1

下列程式碼範例示範如何從 TripModelManager/GMTCTripService 取得 TripModel,並為其設定事件監聽器。

Java

// Start journey sharing after a trip has been created via Fleet Engine.
TripModelManager tripModelManager = consumerApi.getTripModelManager();

// Get a TripModel object.
TripModel tripModel = tripModelManager.getTripModel(tripName);

// Register a listener on the trip.
TripModelCallback tripCallback = new TripModelCallback() {
  ...
};
tripModel.registerTripCallback(tripCallback);

// Set the refresh interval.
TripModelOptions tripModelOptions = TripModelOptions.builder()
    .setRefreshInterval(5000) // interval in milliseconds, so 5 seconds
    .build();
tripModel.setTripModelOptions(tripModelOptions);

// The trip stops auto-refreshing when all listeners are unregistered.
tripModel.unregisterTripCallback(tripCallback);

Kotlin

// Start journey sharing after a trip has been created via Fleet Engine.
val tripModelManager = consumerApi.getTripModelManager()

// Get a TripModel object.
val tripModel = tripModelManager.getTripModel(tripName)

// Register a listener on the trip.
val tripCallback = TripModelCallback() {
  ...
}

tripModel.registerTripCallback(tripCallback)

// Set the refresh interval.
val tripModelOptions =
  TripModelOptions.builder()
    .setRefreshInterval(5000) // interval in milliseconds, so 5 seconds
    .build()

tripModel.setTripModelOptions(tripModelOptions)

// The trip stops auto-refreshing when all listeners are unregistered.
tripModel.unregisterTripCallback(tripCallback)

Swift

let tripService = GMTCServices.shared().tripService

// Create a tripModel instance for listening for updates from the trip
// specified by the trip name.
let tripModel = tripService.tripModel(forTripName: tripName)

// Register for the trip update events.
tripModel.register(self)

// Set the refresh interval (in seconds).
tripModel.options.autoRefreshTimeInterval = 5

// Unregister for the trip update events.
tripModel.unregisterSubscriber(self)

Objective-C

GMTCTripService *tripService = [GMTCServices sharedServices].tripService;

// Create a tripModel instance for listening for updates from the trip
// specified by the trip name.
GMTCTripModel *tripModel = [tripService tripModelForTripName:tripName];

// Register for the trip update events.
[tripModel registerSubscriber:self];

// Set the refresh interval (in seconds).
tripModel.options.autoRefreshTimeInterval = 5;

// Unregister for the trip update events.
[tripModel unregisterSubscriber:self];

範例 2

下列程式碼範例示範如何設定 TripModelCallback 事件監聽器和 GMTCTripModelSubscriber 訂閱者。

Java

// Implements a callback for the trip model so your app can listen for trip
// updates from Fleet Engine.
TripModelCallback subscriber =
  new TripModelCallback() {

    @Override
    public void onTripStatusUpdated(TripInfo tripInfo, @TripStatus int status) {
      // ...
    }

    @Override
    public void onTripActiveRouteUpdated(TripInfo tripInfo, List<LatLng> route) {
      // ...
    }

    @Override
    public void onTripVehicleLocationUpdated(
        TripInfo tripInfo, @Nullable VehicleLocation vehicleLocation) {
      // ...
    }

    @Override
    public void onTripPickupLocationUpdated(
        TripInfo tripInfo, @Nullable TerminalLocation pickup) {
      // ...
    }

    @Override
    public void onTripPickupTimeUpdated(TripInfo tripInfo, @Nullable Long timestampMillis) {
      // ...
    }

    @Override
    public void onTripDropoffLocationUpdated(
        TripInfo tripInfo, @Nullable TerminalLocation dropoff) {
      // ...
    }

    @Override
    public void onTripDropoffTimeUpdated(TripInfo tripInfo, @Nullable Long timestampMillis) {
      // ...
    }

    @Override
    public void onTripETAToNextWaypointUpdated(
        TripInfo tripInfo, @Nullable Long timestampMillis) {
      // ...
    }

    @Override
    public void onTripActiveRouteRemainingDistanceUpdated(
        TripInfo tripInfo, @Nullable Integer distanceMeters) {
      // ...
    }

    @Override
    public void onTripUpdateError(TripInfo tripInfo, TripUpdateError error) {
      // ...
    }

    @Override
    public void onTripUpdated(TripInfo tripInfo) {
      // ...
    }

    @Override
    public void onTripRemainingWaypointsUpdated(
        TripInfo tripInfo, List<TripWaypoint> waypointList) {
      // ...
    }

    @Override
    public void onTripIntermediateDestinationsUpdated(
        TripInfo tripInfo, List<TerminalLocation> intermediateDestinations) {
      // ...
    }

    @Override
    public void onTripRemainingRouteDistanceUpdated(
        TripInfo tripInfo, @Nullable Integer distanceMeters) {
      // ...
    }

    @Override
    public void onTripRemainingRouteUpdated(TripInfo tripInfo, List<LatLng> route) {
      // ...
    }
  };

Kotlin

// Implements a callback for the trip model so your app can listen for trip
// updates from Fleet Engine.
val subscriber =
  object : TripModelCallback() {
    override fun onTripStatusUpdated(tripInfo: TripInfo, status: @TripStatus Int) {
      // ...
    }

    override fun onTripActiveRouteUpdated(tripInfo: TripInfo, route: List<LatLng>) {
      // ...
    }

    override fun onTripVehicleLocationUpdated(
      tripInfo: TripInfo,
      vehicleLocation: VehicleLocation?
    ) {
      // ...
    }

    override fun onTripPickupLocationUpdated(tripInfo: TripInfo, pickup: TerminalLocation?) {
      // ...
    }

    override fun onTripPickupTimeUpdated(tripInfo: TripInfo, timestampMillis: Long?) {
      // ...
    }

    override fun onTripDropoffLocationUpdated(tripInfo: TripInfo, dropoff: TerminalLocation?) {
      // ...
    }

    override fun onTripDropoffTimeUpdated(tripInfo: TripInfo, timestampMillis: Long?) {
      // ...
    }

    override fun onTripETAToNextWaypointUpdated(tripInfo: TripInfo, timestampMillis: Long?) {
      // ...
    }

    override fun onTripActiveRouteRemainingDistanceUpdated(
      tripInfo: TripInfo,
      distanceMeters: Int?
    ) {
      // ...
    }

    override fun onTripUpdateError(tripInfo: TripInfo, error: TripUpdateError) {
      // ...
    }

    override fun onTripUpdated(tripInfo: TripInfo) {
      // ...
    }

    override fun onTripRemainingWaypointsUpdated(
      tripInfo: TripInfo,
      waypointList: List<TripWaypoint>
    ) {
      // ...
    }

    override fun onTripIntermediateDestinationsUpdated(
      tripInfo: TripInfo,
      intermediateDestinations: List<TerminalLocation>
    ) {
      // ...
    }

    override fun onTripRemainingRouteDistanceUpdated(tripInfo: TripInfo, distanceMeters: Int?) {
      // ...
    }

    override fun onTripRemainingRouteUpdated(tripInfo: TripInfo, route: List<LatLng>) {
      // ...
    }
  }

Swift

class TripModelSubscriber: NSObject, GMTCTripModelSubscriber {

  func tripModel(_: GMTCTripModel, didUpdate trip: GMTSTrip?, updatedPropertyFields: GMTSTripPropertyFields) {
    // Update the UI with the new `trip` data.
    updateUI(with: trip)
    ...
  }

  func tripModel(_: GMTCTripModel, didUpdate tripStatus: GMTSTripStatus) {
    // Handle trip status did change.
  }

  func tripModel(_: GMTCTripModel, didUpdateActiveRoute activeRoute: [GMTSLatLng]?) {
    // Handle trip active route did update.
  }

  func tripModel(_: GMTCTripModel, didUpdate vehicleLocation: GMTSVehicleLocation?) {
    // Handle vehicle location did update.
  }

  func tripModel(_: GMTCTripModel, didUpdatePickupLocation pickupLocation: GMTSTerminalLocation?) {
    // Handle pickup location did update.
  }

  func tripModel(_: GMTCTripModel, didUpdateDropoffLocation dropoffLocation: GMTSTerminalLocation?) {
    // Handle drop off location did update.
  }

  func tripModel(_: GMTCTripModel, didUpdatePickupETA pickupETA: TimeInterval) {
    // Handle the pickup ETA did update.
  }

  func tripModel(_: GMTCTripModel, didUpdateDropoffETA dropoffETA: TimeInterval) {
    // Handle the drop off ETA did update.
  }

  func tripModel(_: GMTCTripModel, didUpdateRemaining remainingWaypoints: [GMTSTripWaypoint]?) {
    // Handle updates to the pickup, dropoff or intermediate destinations of the trip.
  }

  func tripModel(_: GMTCTripModel, didFailUpdateTripWithError error: Error?) {
    // Handle the error.
  }

  func tripModel(_: GMTCTripModel, didUpdateIntermediateDestinations intermediateDestinations: [GMTSTerminalLocation]?) {
    // Handle the intermediate destinations being updated.
  }

  ...
}

Objective-C

@interface TripModelSubscriber : NSObject <GMTCTripModelSubscriber>
@end

@implementation TripModelSubscriber

- (void)tripModel:(GMTCTripModel *)tripModel
            didUpdateTrip:(nullable GMTSTrip *)trip
    updatedPropertyFields:(GMTSTripPropertyFields)updatedPropertyFields {
  // Update the UI with the new `trip` data.
  [self updateUIWithTrip:trip];
  ...
}

- (void)tripModel:(GMTCTripModel *)tripModel didUpdateTripStatus:(enum GMTSTripStatus)tripStatus {
  // Handle trip status did change.
}

- (void)tripModel:(GMTCTripModel *)tripModel
    didUpdateActiveRoute:(nullable NSArray<GMTSLatLng *> *)activeRoute {
  // Handle trip route did update.
}

- (void)tripModel:(GMTCTripModel *)tripModel
    didUpdateVehicleLocation:(nullable GMTSVehicleLocation *)vehicleLocation {
  // Handle vehicle location did update.
}

- (void)tripModel:(GMTCTripModel *)tripModel
    didUpdatePickupLocation:(nullable GMTSTerminalLocation *)pickupLocation {
  // Handle pickup location did update.
}

- (void)tripModel:(GMTCTripModel *)tripModel
    didUpdateDropoffLocation:(nullable GMTSTerminalLocation *)dropoffLocation {
  // Handle drop off location did update.
}

- (void)tripModel:(GMTCTripModel *)tripModel didUpdatePickupETA:(NSTimeInterval)pickupETA {
  // Handle the pickup ETA did update.
}

- (void)tripModel:(GMTCTripModel *)tripModel
    didUpdateRemainingWaypoints:(nullable NSArray<GMTSTripWaypoint *> *)remainingWaypoints {
  // Handle updates to the pickup, dropoff or intermediate destinations of the trip.
}

- (void)tripModel:(GMTCTripModel *)tripModel didUpdateDropoffETA:(NSTimeInterval)dropoffETA {
  // Handle the drop off ETA did update.
}

- (void)tripModel:(GMTCTripModel *)tripModel didFailUpdateTripWithError:(nullable NSError *)error {
  // Handle the error.
}

- (void)tripModel:(GMTCTripModel *)tripModel
    didUpdateIntermediateDestinations:
        (nullable NSArray<GMTSTerminalLocation *> *)intermediateDestinations {
  // Handle the intermediate destinations being updated.
}
…
@end

你隨時可以按照下列方式查看行程資訊:

步驟 7:在消費者應用程式中顯示歷程

您可以透過下列方式存取「共乘」和「外送」使用者介面元素 API:

範例

以下程式碼範例示範如何啟動旅程共用使用者介面。

Java

JourneySharingSession session = JourneySharingSession.createInstance(tripModel);
consumerController.showSession(session);

Kotlin

val session = JourneySharingSession.createInstance(tripModel)
consumerController.showSession(session)

Swift

let journeySharingSession = GMTCJourneySharingSession(tripModel: tripModel)
mapView.show(journeySharingSession)

Objective-C

GMTCJourneySharingSession *journeySharingSession =
    [[GMTCJourneySharingSession alloc] initWithTripModel:tripModel];
[self.mapView showMapViewSession:journeySharingSession];

情境示例

假設進行一趟返回行程,車輛已經在第一趟行程期間吸引到消費者,司機在完成目前行程後收到前往其他消費者的要求後,車輛已抵達下車地點。





此時,第一趟行程的消費者會看到以下內容。





同時,第二趟行程的消費者會看到以下內容。





根據預設,Consumer SDK 只會顯示路線中的可用路段,但您可以選擇顯示其餘的路段,包括目的地。

如要顯示其他行程的路線控點資訊,可以使用以下方式存取與行程相關的所有路線控點:

步驟 8:在機群引擎中管理行程狀態

您可以使用其中一個 TripStatus 列舉值指定行程狀態。當行程狀態變更 (例如從 ENROUTE_TO_PICKUP 變更為 ARRIVED_AT_PICKUP) 時,您必須透過 Fleet Engine 更新行程狀態。行程狀態一律以 NEW 的值開頭,結尾則是 COMPLETECANCELED。詳情請參閱trip_status

範例

以下後端整合範例示範如何在 Fleet Engine 中更新行程狀態。

static final String PROJECT_ID = "my-rideshare-co-gcp-project";
static final String TRIP_ID = "trip-8241890";

String tripName = "providers/" + PROJECT_ID + "/trips/" + TRIP_ID;

TripServiceBlockingStub tripService = TripService.newBlockingStub(channel);

// Trip settings to be updated.
Trip trip = Trip.newBuilder()
    .setTripStatus(TripStatus.ARRIVED_AT_PICKUP)
    .build();

// Trip update request
UpdateTripRequest updateTripRequest = UpdateTripRequest.newBuilder()
    .setName(tripName)
    .setTrip(trip)
    .setUpdateMask(FieldMask.newBuilder().addPaths("trip_status"))
    .build();

// Error handling.
try {
  Trip updatedTrip = tripService.updateTrip(updateTripRequest);
} catch (StatusRuntimeException e) {
  Status s = e.getStatus();
  switch (s.getCode()) {
    case NOT_FOUND:            // The trip doesn't exist.
      break;
    case FAILED_PRECONDITION:  // The given trip status is invalid.
      break;
    case PERMISSION_DENIED:
      break;
  }
  return;
}