監聽導覽事件

您可以參考本指南，讓應用程式監聽並回應使用者沿著路線前進時發生的各種事件變化。本指南不會說明如何定義路線，只會說明如何回應沿路的事件。

總覽

iOS 版 Navigation SDK 會提供與使用者位置和路線沿途狀況相關的事件監聽器，以及重要時間和距離資料。在地圖的 View Controller 中，應用程式需要採用下列事件監聽器的通訊協定：GMSRoadSnappedLocationProviderListener 和 GMSNavigatorListener。

以下清單列出可用於導覽事件的事件監聽器方法：

查看程式碼

/*
 * Copyright 2020 Google Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import GoogleNavigation
import UIKit

class ViewController: UIViewController,
  GMSNavigatorListener,
  GMSRoadSnappedLocationProviderListener
{

  var mapView: GMSMapView!
  var locationManager: CLLocationManager!

  override func loadView() {

    locationManager = CLLocationManager()

    let camera = GMSCameraPosition.camera(withLatitude: 47.67, longitude: -122.20, zoom: 14)
    mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)

    // Add listeners for GMSNavigator and GMSRoadSnappedLocationProvider.
    mapView.navigator?.add(self)
    mapView.roadSnappedLocationProvider?.add(self)

    // Set the time update threshold (seconds) and distance update threshold (meters).
    mapView.navigator?.timeUpdateThreshold = 10
    mapView.navigator?.distanceUpdateThreshold = 100

    // Show the terms and conditions.
    let companyName = "Ride Sharing Co."
    GMSNavigationServices.showTermsAndConditionsDialogIfNeeded(
      withCompanyName: companyName
    ) { termsAccepted in
      if termsAccepted {
        // Enable navigation if the user accepts the terms.
        self.mapView.isNavigationEnabled = true

        // Request authorization to use location services.
        self.locationManager.requestAlwaysAuthorization()

        // Request authorization for alert notifications which deliver guidance instructions
        // in the background.
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert]) {
          granted, error in
          // Handle denied authorization to display notifications.
          if !granted || error != nil {
            print("Authorization to deliver notifications was rejected.")
          }
        }
      } else {
        // Handle the case when the user rejects the terms and conditions.
      }
    }

    view = mapView

    makeButton()
  }

  // Create a route and start guidance.
  @objc func startNav() {
    var destinations = [GMSNavigationWaypoint]()
    destinations.append(
      GMSNavigationWaypoint.init(
        placeID: "ChIJnUYTpNASkFQR_gSty5kyoUk",
        title: "PCC Natural Market")!)
    destinations.append(
      GMSNavigationWaypoint.init(
        placeID: "ChIJJ326ROcSkFQRBfUzOL2DSbo",
        title: "Marina Park")!)

    mapView.navigator?.setDestinations(destinations) { routeStatus in
      guard routeStatus == .OK else {
        print("Handle route statuses that are not OK.")
        return
      }
      self.mapView.navigator?.isGuidanceActive = true
      self.mapView.cameraMode = .following
      self.mapView.locationSimulator?.simulateLocationsAlongExistingRoute()
    }

    mapView.roadSnappedLocationProvider?.startUpdatingLocation()
  }

  // Listener to handle continuous location updates.
  func locationProvider(
    _ locationProvider: GMSRoadSnappedLocationProvider,
    didUpdate location: CLLocation
  ) {
    print("Location: \(location.description)")
  }

  // Listener to handle speeding events.
  func navigator(
    _ navigator: GMSNavigator, didUpdateSpeedingPercentage percentageAboveLimit: CGFloat
  ) {
    print("Speed is \(percentageAboveLimit) above the limit.")
  }

  // Listener to handle arrival events.
  func navigator(_ navigator: GMSNavigator, didArriveAt waypoint: GMSNavigationWaypoint) {
    print("You have arrived at: \(waypoint.title)")
    mapView.navigator?.continueToNextDestination()
    mapView.navigator?.isGuidanceActive = true
  }

  // Listener for route change events.
  func navigatorDidChangeRoute(_ navigator: GMSNavigator) {
    print("The route has changed.")
  }

  // Listener for time to next destination.
  func navigator(_ navigator: GMSNavigator, didUpdateRemainingTime time: TimeInterval) {
    print("Time to next destination: \(time)")
  }

  // Delegate for distance to next destination.
  func navigator(
    _ navigator: GMSNavigator,
    didUpdateRemainingDistance distance: CLLocationDistance
  ) {
    let miles = distance * 0.00062137
    print("Distance to next destination: \(miles) miles.")
  }

  // Delegate for traffic updates to next destination
  func navigator(
    _ navigator: GMSNavigator,
    didUpdate delayCategory: GMSNavigationDelayCategory
  ) {
    print("Delay category to next destination: \(String(describing: delayCategory)).")
  }

  // Delegate for suggested lighting mode changes.
  func navigator(
    _ navigator: GMSNavigator,
    didChangeSuggestedLightingMode lightingMode: GMSNavigationLightingMode
  ) {
    print("Suggested lighting mode has changed: \(String(describing: lightingMode))")

    // Change to the suggested lighting mode.
    mapView.lightingMode = lightingMode
  }

  // Add a button to the view.
  func makeButton() {
    // Start navigation.
    let navButton = UIButton(frame: CGRect(x: 5, y: 150, width: 200, height: 35))
    navButton.backgroundColor = .blue
    navButton.alpha = 0.5
    navButton.setTitle("Start navigation", for: .normal)
    navButton.addTarget(self, action: #selector(startNav), for: .touchUpInside)
    self.mapView.addSubview(navButton)
  }

}
 
/*
 * Copyright 2020 Google Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#import "ViewController.h"
@import GoogleNavigation;

@interface ViewController () <GMSNavigatorListener, GMSRoadSnappedLocationProviderListener>

@end

@implementation ViewController {
  GMSMapView *_mapView;
  CLLocationManager *_locationManager;
}

- (void)loadView {

  _locationManager = [[CLLocationManager alloc] init];

  GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:47.67
                                                          longitude:-122.20
                                                               zoom:14];
  _mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera];

  // Add listeners for GMSNavigator and GMSRoadSnappedLocationProvider.
  [_mapView.navigator addListener:self];
  [_mapView.roadSnappedLocationProvider addListener:self];

  // Set the time update threshold (seconds) and distance update threshold (meters).
  _mapView.navigator.timeUpdateThreshold = 10;
  _mapView.navigator.distanceUpdateThreshold = 100;

  // Show the terms and conditions.
  NSString *companyName = @"Ride Sharing Co.";
  [GMSNavigationServices
   showTermsAndConditionsDialogIfNeededWithCompanyName:companyName
                                              callback:^(BOOL termsAccepted) {
     if (termsAccepted) {
       // Enable navigation if the user accepts the terms.
       _mapView.navigationEnabled = YES;

       // Request authorization to use location services.
       [_locationManager requestAlwaysAuthorization];

     } else {
       // Handle the case when the user rejects the terms and conditions.
     }
   }];

  self.view = _mapView;

  [self makeButton];
}

// Create a route and initiate navigation.
- (void)startNav {
  NSArray<GMSNavigationWaypoint *> *destinations =
  @[[[GMSNavigationWaypoint alloc] initWithPlaceID:@"ChIJnUYTpNASkFQR_gSty5kyoUk"
                                             title:@"PCC Natural Market"],
    [[GMSNavigationWaypoint alloc] initWithPlaceID:@"ChIJJ326ROcSkFQRBfUzOL2DSbo"
                                             title:@"Marina Park"]];

  [_mapView.navigator setDestinations:destinations
                             callback:^(GMSRouteStatus routeStatus){
                               _mapView.navigator.guidanceActive = YES;
                               _mapView.navigator.sendsBackgroundNotifications = YES;
                               _mapView.cameraMode = GMSNavigationCameraModeFollowing;
                               [_mapView.locationSimulator simulateLocationsAlongExistingRoute];
                             }];

  [_mapView.roadSnappedLocationProvider startUpdatingLocation];
}

#pragma mark - GMSNavigatorListener
// Listener for continuous location updates.
- (void)locationProvider:(GMSRoadSnappedLocationProvider *)locationProvider
      didUpdateLocation:(CLLocation *)location {
  NSLog(@"Location: %@", location.description);
}

// Listener to handle speeding events.
- (void)navigator:(GMSNavigator *)navigator
    didUpdateSpeedingPercentage:(CGFloat)percentageAboveLimit {
  NSLog(@"Speed is %f percent above the limit.", percentageAboveLimit);
}

// Listener to handle arrival events.
- (void)navigator:(GMSNavigator *)navigator didArriveAtWaypoint:(GMSNavigationWaypoint *)waypoint {
  NSLog(@"You have arrived at: %@", waypoint.title);
  [_mapView.navigator continueToNextDestination];
  _mapView.navigator.guidanceActive = YES;
}

// Listener for route change events.
- (void)navigatorDidChangeRoute:(GMSNavigator *)navigator {
  NSLog(@"The route has changed.");
}

// Listener for time to next destination.
- (void)navigator:(GMSNavigator *)navigator didUpdateRemainingTime:(NSTimeInterval)time {
  NSLog(@"Time to next destination: %f", time);
}

// Listener for distance to next destination.
- (void)navigator:(GMSNavigator *)navigator
      didUpdateRemainingDistance:(CLLocationDistance)distance {
  double miles = distance * 0.00062137;
  NSLog(@"%@", [NSString stringWithFormat:@"Distance to next destination: %.2f.", miles]);
}

// Listener for traffic updates for next destination
- (void)navigator:(GMSNavigator *)navigator
    didUpdateDelayCategory:(GMSNavigationDelayCategory)delayCategory {
  NSLog(@"Delay category to next destination: %ld.", delayCategory);
}

// Listener for suggested lighting mode changes.
-(void)navigator:(GMSNavigator *)navigator
      didChangeSuggestedLightingMode:(GMSNavigationLightingMode)lightingMode {
  NSLog(@"Suggested lighting mode has changed: %ld", (long)lightingMode);

  // Change to the suggested lighting mode.
  _mapView.lightingMode = lightingMode;
}

#pragma mark - Programmatic UI elements

// Add a button to the view.
- (void)makeButton {
  // Start navigation.
  UIButton *navButton = [UIButton buttonWithType:UIButtonTypeCustom];
  [navButton addTarget:self
                action:@selector(startNav)
      forControlEvents:UIControlEventTouchUpInside];
  [navButton setTitle:@"Navigate" forState:UIControlStateNormal];
  [navButton setBackgroundColor:[UIColor blueColor]];
  [navButton setAlpha:0.5];
  navButton.frame = CGRectMake(5.0, 150.0, 100.0, 35.0);
  [_mapView addSubview:navButton];
}

@end

宣告符合必要通訊協定

在實作導覽方法之前，View Controller 必須採用下列通訊協定：

SwiftObjective-C

class ViewController: UIViewController, GMSNavigatorListener,
GMSRoadSnappedLocationProviderListener {


@interface ViewController () <GMSNavigatorListener,
GMSRoadSnappedLocationProviderListener>

@end

採用導覽通訊協定後，請將事件監聽器設為檢視控制器。舉例來說，您可以將下列程式碼新增至 viewDidLoad() 方法。

SwiftObjective-C

mapView.navigator?.add(self) mapView.roadSnappedLocationProvider?.add(self)


[_mapView.navigator addListener:self]; [_mapView.roadSnappedLocationProvider
addListener:self];

接收或停止位置更新

如要在地圖上顯示使用者的進度，就必須更新位置。

location 例項會公開下列屬性：

位置屬性 說明
高度 目前的高度。
coordinate.latitude 目前經過道路對齊的緯度座標。
coordinate.longitude 目前經過路徑修正的經度座標。
課程 目前航向 (以度為單位)。
速度 目前速度。
時間戳記 目前讀數的日期/時間。

如要接收持續的位置更新，請呼叫 mapView.roadSnappedLocationProvider.startUpdatingLocation，並使用 GMSRoadSnappedLocationProviderListener 處理 didUpdateLocation 事件。

下例示範如何呼叫 startUpdatingLocation：

SwiftObjective-C

mapView.roadSnappedLocationProvider.startUpdatingLocation()


[_mapView.roadSnappedLocationProvider startUpdatingLocation];

以下程式碼會建立 GMSRoadSnappedLocationProviderListener，用於處理 didUpdateLocation 事件。

SwiftObjective-C

func locationProvider(_ locationProvider: GMSRoadSnappedLocationProvider,
didUpdate location: CLLocation) { print("Location: \(location.description)") }


-   (void)locationProvider:(GMSRoadSnappedLocationProvider *)locationProvider
    didUpdateLocation:(CLLocation *)location { NSLog(@"Location: %@",
    location.description); }

如要在應用程式處於背景執行時接收位置更新通知，請將 allowsBackgroundLocationUpdates 設為 true：

SwiftObjective-C

mapView.roadSnappedLocationProvider.allowsBackgroundLocationUpdates = true


 _mapView.roadSnappedLocationProvider.allowsBackgroundLocationUpdates = YES;

偵測到抵達事件

應用程式會使用 didArriveAtWaypoint 事件偵測到達目的地時機。您可以呼叫 continueToNextDestination()，然後重新啟用導航功能，以便繼續導航並前往下一個路標。應用程式必須在呼叫 continueToNextDestination() 後重新啟用指引。

應用程式呼叫 continueToNextDestination 後，導航器就不會再有先前目的地的資料。如要分析路線路段的相關資訊，您必須先從導航器中擷取資訊，再呼叫 continueToNextDestination()。

以下程式碼範例顯示處理 didArriveAtWaypoint 事件的方法：

SwiftObjective-C

func navigator(_ navigator: GMSNavigator, didArriveAt waypoint:
GMSNavigationWaypoint) { print("You have arrived at: \(waypoint.title)")
mapView.navigator?.continueToNextDestination()
mapView.navigator?.isGuidanceActive = true }


-   (void)navigator:(GMSNavigator *)navigator
    didArriveAtWaypoint:(GMSNavigationWaypoint *)waypoint { NSLog(@"You have
    arrived at: %@", waypoint.title); [_mapView.navigator
    continueToNextDestination]; _mapView.navigator.guidanceActive = YES; }

接收路線變更更新

如要在路徑變更時收到通知，請建立方法來處理 navigatorDidChangeRoute 事件。您可以使用 GMSNavigator 的 routeLegs 和 currentRouteLeg 屬性存取新路徑。

SwiftObjective-C

func navigatorDidChangeRoute(_ navigator: GMSNavigator) { print("The route has
changed.") }


-   (void)navigatorDidChangeRoute:(GMSNavigator *)navigator { NSLog(@"The route
    has changed."); }

接收到達時間更新

如要接收持續性的到達時間更新，請建立方法來處理 didUpdateRemainingTime 事件。time 參數會提供預估時間 (以秒為單位)，直到下一個目的地為止。

SwiftObjective-C

func navigator(_ navigator: GMSNavigator, didUpdateRemainingTime time:
TimeInterval) { print("Time to next destination: \(time)") }


-   (void)navigator:(GMSNavigator *)navigator
    didUpdateRemainingTime:(NSTimeInterval)time { NSLog(@"Time to next
    destination: %f", time); }

如要設定前往下一個目的地的預估時間變更量下限，請在 GMSNavigator 上設定 timeUpdateThreshold 屬性。這個值以秒為單位。如果未設定此屬性，服務會使用一秒的預設值。

SwiftObjective-C

navigator?.timeUpdateThreshold = 10


navigator.timeUpdateThreshold = 10;

接收目的地更新資訊

如要接收持續更新的目的地距離，請建立方法來處理 didUpdateRemainingDistance 事件。distance 參數會提供下一個目的地的預估距離 (以公尺為單位)。

SwiftObjective-C

func navigator(_ navigator: GMSNavigator, didUpdateRemainingDistance distance:
CLLocationDistance) { let miles = distance * 0.00062137 print("Distance to next
destination: \(miles) miles.") }


-   (void)navigator:(GMSNavigator *)navigator
    didUpdateRemainingDistance:(CLLocationDistance)distance { double miles =
    distance * 0.00062137; NSLog(@"%@", [NSString stringWithFormat:@"Distance to
    next destination: %.2f.", miles]); }

如要設定到下一個目的地的預估距離的變動幅度下限，請在 GMSNavigator 上設定 distanceUpdateThreshold 屬性 (值以公尺為單位)。如果未設定這個屬性，服務會使用一公尺的預設值。

SwiftObjective-C

navigator?.distanceUpdateThreshold = 100


navigator.distanceUpdateThreshold = 100;

接收路況更新

如要持續接收剩餘路線的車流量更新，請建立方法來處理 didUpdateDelayCategory 事件。對 delayCategoryToNextDestination 的呼叫會傳回 GMSNavigationDelayCategory，提供 0 到 3 的值。系統會根據應用程式使用者的目前位置更新類別。如果無法取得流量資料，GMSNavigationDelayCategory 會傳回 0。1 到 3 的數字代表流量從輕度到重度增加。

SwiftObjective-C

func navigator(_ navigator: GMSNavigator, didUpdate delayCategory:
GMSNavigationDelayCategory) { print("Traffic flow to next destination:
\(delayCategory)") }


-   (void)navigator:(GMSNavigator *)navigator
    didUpdateDelayCategory:(GMSNavigationDelayCategory)delayCategory {
    NSLog(@"Traffic flow to next destination: %ld", (long)delayCategory); }

GMSNavigationDelayCategory 屬性會顯示下列延遲層級：

延遲類別 說明
GMSNavigationDelayCategoryNoData 0 - 無法使用，沒有流量資料或
路線。
GMSNavigationDelayCategoryHeavy 1 - 嚴重。
GMSNavigationDelayCategoryMedium 2 - 中度。
GMSNavigationDelayCategoryLight 3 - 燈光。

接收超速更新

如要接收駕駛人超速時的更新通知，請建立方法來處理 didUpdateSpeedingPercentage 事件。

SwiftObjective-C

// Listener to handle speeding events. func navigator( _ navigator:
GMSNavigator, didUpdateSpeedingPercentage percentageAboveLimit: CGFloat ) {
print("Speed is \(percentageAboveLimit) above the limit.") }


// Listener to handle speeding events. - (void)navigator:(GMSNavigator
*)navigator didUpdateSpeedingPercentage:(CGFloat)percentageAboveLimit {
NSLog(@"Speed is %f percent above the limit.", percentageAboveLimit); }

變更建議的照明模式

如要接收照明設備預估變更的更新內容，請建立方法來處理 didChangeSuggestedLightingMode 事件。

SwiftObjective-C

// Define a listener for suggested changes to lighting mode. func navigator(_
navigator: GMSNavigator, didChangeSuggestedLightingMode lightingMode:
GMSNavigationLightingMode) { print("Suggested lighting mode has changed:
\(String(describing: lightingMode))")

 // Make the suggested change. mapView.lightingMode = lightingMode }


// Define a listener for suggested changes to lighting mode.
-(void)navigator:(GMSNavigator *)navigator didChangeSuggestedLightingMode:
(GMSNavigationLightingMode)lightingMode { NSLog(@"Suggested lighting mode has
changed: %ld", (long)lightingMode);

 // Make the suggested change. _mapView.lightingMode = lightingMode; }