Create customized guidance

This page covers the high-level steps you follow to create customized guidance as part of a custom navigation experience.

This process differs from the process described in Navigate a route as follows:

  • You first establish a navigation session independently and obtain a navigator instance through the session rather than by calling the view controller.
  • You set up an event listener to respond to and manage navigation events.
  1. Create a navigation session using GMSNavigationService.createNavigationSession and begin navigation with a setDestination call. Where the Google navigation experience invokes the navigator through the navigation map view, the GMSNavigationServices controls and receives a stream of events from a navigation session independently from a UI instance. This means it can either run without a UI, or get passed to any UI-based experience. With this approach, the navigation session continues to run in your app until the last reference is removed from it.
  2. Establish a road-snapped location provider. Use the location provider if you want your app to have continuous location monitoring, such as when displaying a navigation view with a blue dot along the route.
  3. Set up a listener for detailed turn-by-turn guidance by implementing the GMSNavigatorListener protocol. Then, transform that information into whatever is needed for your custom navigation experience. For example:
    1. Implement text-only fields for simple screen casting of directions.
    2. Design and populate fields for your own UI.
  4. Set up a navigation simulator. This is necessary for development and testing.

Create an independent navigation session

The following code snippet from the demo shows navigation established independently from the view controller. The code then adds an overview map configured to show the current road-snapped location.

// Create the navigation session.

 _navigationSession = [GMSNavigationServices createNavigationSession];
 GMSRoadSnappedLocationProvider *roadSnappedLocationProvider =
     _navigationSession.roadSnappedLocationProvider;
 [roadSnappedLocationProvider startUpdatingLocation];
 GMSNavigator *navigator = _navigationSession.navigator;
 [navigator addListener:self];
 navigator.voiceGuidance = GMSNavigationVoiceGuidanceSilent;
 navigator.sendsBackgroundNotifications = NO;
 _navigationSession.started = YES;
​​ [navigator setDestinations:@[ destination ]
                   callback:^(GMSRouteStatus routeStatus) {
                      // …handle changes in route status.
                    }];

 // Add an overview map.
 _mapView = [[GMSMapView alloc] initWithFrame:CGRectZero];
 [self.mainStackView addArrangedSubview:_mapView];
 [self.mainStackView setNeedsLayout];
 _mapView.settings.compassButton = YES;
 _mapView.delegate = self;
 _mapView.myLocationEnabled = YES;
 _mapView.roadSnappedMyLocationSource = roadSnappedLocationProvider;

Passing navigation from a custom experience to the Google experience

This code snippet illustrates how your app can allow the user to enter the Google navigation experience from a custom navigation experience. This code snippet also shows how your app makes this transition while sharing the map.

`UIButton *button = [UIButton buttonWithType:UIButtonTypePlain`];

[`button addTarget:self action:@selector(didTapEnterGoogleNavigationButton:)
forControlState:[_directionsButton addTarget:self`];

`…`

[`_mapView enableNavigationWithSession:_navigationSession`];