Navigate between two points and dynamically recalculate an alternate route when the original route is unavailable.
Use case
While traveling between destinations, field workers use navigation to get live directions based on their locations. In cases where a field worker makes a wrong turn, or if the route suggested is blocked due to a road closure, it is necessary to calculate an alternate route to the original destination.
How to use the sample
Tap "Navigate" to simulate traveling and to receive directions from a preset starting point to a preset destination. Observe how the route is recalculated when the simulation does not follow the suggested route. Tap "Recenter" to reposition the viewpoint. Tap "Reset" to start the simulation from the beginning.
How it works
- Create a
RouteTaskusing local network data. - Generate default
RouteParametersusingRouteTask.createDefaultParameters(). - Set
returnRoutes,returnStops, andreturnDirectionson theRouteParameterstotrue. - Add
Stops to the parameters' list ofstopsusingRouteParameters.setStops(...). - Solve the route using
routeTask.solveRoute(routeParameters)to get anRouteResult. - Create an
RouteTrackerusing the route result, and the index of the desired route to take. - Enable rerouting in the route tracker using
routeTracker.enableRerouting(reroutingParameters). PassReroutingStrategy.ToNextWaypointas the value ofstrategyto specify that in the case of a reroute, the new route goes from present location to next waypoint or stop. - Retrieve the
routeTracker.trackingStatusstate flow values to track status and progress updates as a route is traversed.
Relevant API
- DestinationStatus
- DirectionManeuver
- Location
- LocationDataSource
- ReroutingStrategy
- Route
- RouteParameters
- RouteTask
- RouteTracker
- RouteTrackerLocationDataSource
- SimulatedLocationDataSource
- Stop
- VoiceGuidance
About the data
The San Diego Geodatabase route taken in this sample goes from the San Diego Convention Center, site of the annual Esri User Conference, to the Fleet Science Center, San Diego.
Additional information
The route tracker will start a rerouting calculation automatically as necessary when the device's location indicates that it is off-route. The route tracker also validates that the device is "on" the transportation network. If it is not (e.g. in a parking lot), rerouting will not occur until the device location indicates that it is back "on" the transportation network.
Tags
directions, maneuver, navigation, route, turn-by-turn, voice
Sample Code
/* Copyright 2025 Esri * * 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. * */ package com.esri.arcgismaps.sample.navigateroutewithrerouting.components import android.app.Application import android.speech.tts.TextToSpeech import android.text.format.DateUtils import androidx.compose.runtime.getValue import androidx.compose.runtime.mutableStateOf import androidx.compose.runtime.setValue import androidx.core.content.ContextCompat import androidx.lifecycle.AndroidViewModel import androidx.lifecycle.viewModelScope import com.arcgismaps.Color import com.arcgismaps.geometry.Geometry import com.arcgismaps.geometry.Point import com.arcgismaps.geometry.Polyline import com.arcgismaps.geometry.SpatialReference import com.arcgismaps.location.LocationDisplayAutoPanMode import com.arcgismaps.location.RouteTrackerLocationDataSource import com.arcgismaps.location.SimulatedLocationDataSource import com.arcgismaps.location.SimulationParameters import com.arcgismaps.mapping.ArcGISMap import com.arcgismaps.mapping.BasemapStyle import com.arcgismaps.mapping.symbology.SimpleLineSymbol import com.arcgismaps.mapping.symbology.SimpleLineSymbolStyle import com.arcgismaps.mapping.symbology.SimpleMarkerSymbol import com.arcgismaps.mapping.symbology.SimpleMarkerSymbolStyle import com.arcgismaps.mapping.view.Graphic import com.arcgismaps.mapping.view.GraphicsOverlay import com.arcgismaps.mapping.view.LocationDisplay import com.arcgismaps.navigation.DestinationStatus import com.arcgismaps.navigation.ReroutingParameters import com.arcgismaps.navigation.ReroutingStrategy import com.arcgismaps.navigation.RouteTracker import com.arcgismaps.navigation.TrackingStatus import com.arcgismaps.tasks.networkanalysis.RouteParameters import com.arcgismaps.tasks.networkanalysis.RouteResult import com.arcgismaps.tasks.networkanalysis.RouteTask import com.arcgismaps.tasks.networkanalysis.Stop import com.arcgismaps.toolkit.geoviewcompose.MapViewProxy import com.esri.arcgismaps.sample.navigateroutewithrerouting.R import com.esri.arcgismaps.sample.sampleslib.components.MessageDialogViewModel import kotlinx.coroutines.Job import kotlinx.coroutines.cancelAndJoin import kotlinx.coroutines.flow.filter import kotlinx.coroutines.launch import java.io.File import java.time.Instant class NavigateRouteWithReroutingViewModel(application: Application) : AndroidViewModel(application) { // Path of the San Diego transport network used by the route task private val provisionPath: String by lazy { application.getExternalFilesDir(null)?.path.toString() + File.separator + application.getString(R.string.navigate_route_with_rerouting_app_name) } // Passed to the composable MapView to set the mapViewProxy val mapViewProxy = MapViewProxy() // The map to display basemap, route traveled & route ahead graphics val arcGISMap = ArcGISMap(BasemapStyle.ArcGISStreets) // Graphics overlay to display the route ahead and traveled graphics val graphicsOverlay = GraphicsOverlay() // Keep track of the the location display job when navigation is enabled private var locationDisplayJob: Job? = null // Default location display object, which is updated by rememberLocationDisplay private var locationDisplay: LocationDisplay = LocationDisplay() // Starting point: San Diego Convention Center private val startingStop = Stop(Point(-117.160386, 32.706608, SpatialReference.wgs84())) .apply { name = "San Diego Convention Center" } // Destination point: Fleet Science Center private val destinationStop = Stop(Point(-117.146679, 32.730351, SpatialReference.wgs84())) .apply { name = "RH Fleet Aerospace Museum" } // Generate a route with directions and stops for navigation private val routeTask = RouteTask( pathToDatabase = "$provisionPath/sandiego.geodatabase", networkName = "Streets_ND" ) // The route parameters needed to calculate a route from a start and stop point private var routeParameters = RouteParameters() // The resulted route from the route task using the route parameters private var routeResult: RouteResult? = null // Instance of the route ahead polyline private var routeAheadGraphic: Graphic = Graphic( symbol = SimpleLineSymbol( SimpleLineSymbolStyle.Dash, Color(getColorArgb(com.esri.arcgismaps.sample.sampleslib.R.color.colorPrimary)), 3f ) ) // Graphic to represent the route that's been traveled (initially empty) private var routeTraveledGraphic: Graphic = Graphic( symbol = SimpleLineSymbol( SimpleLineSymbolStyle.Solid, Color.black, 3f ) ) var distanceRemainingText by mutableStateOf("") private set var timeRemainingText by mutableStateOf("") private set var nextDirectionText by mutableStateOf("") private set var isNavigateButtonEnabled by mutableStateOf(true) private set var isRecenterButtonEnabled by mutableStateOf(false) private set // Boolean to check if Android text-speech is initialized private var isTextToSpeechInitialized = false // Instance of Android text-speech private var textToSpeech: TextToSpeech? = null // JSON of polylines of the path for the simulated data source private val polylineJSON: String by lazy { application.getString(R.string.simulation_path_json) } // Polyline representing simulation path private val simulationPolyline = Geometry.fromJsonOrNull(polylineJSON) as Polyline // Create a ViewModel to handle dialog interactions val messageDialogVM: MessageDialogViewModel = MessageDialogViewModel() fun initialize(locationDisplay: LocationDisplay) { // Set the location display to be used by this view model this.locationDisplay = locationDisplay // Initialize text-to-speech to replay navigation voice guidance val context = getApplication<Application>().applicationContext textToSpeech = TextToSpeech(context) { status -> if (status == TextToSpeech.SUCCESS) { textToSpeech?.language = context.resources.configuration.locales[0] isTextToSpeechInitialized = true } } // Load and set the route parameters viewModelScope.launch { routeParameters = routeTask.createDefaultParameters() .getOrElse { return@launch messageDialogVM.showMessageDialog(it) }.apply { setStops(listOf(startingStop, destinationStop)) returnDirections = true returnStops = true returnRoutes = true } // Load the map arcGISMap.load().onFailure { return@launch messageDialogVM.showMessageDialog(it) } // Get the solved route result routeResult = routeTask.solveRoute(routeParameters).getOrElse { return@launch messageDialogVM.showMessageDialog(it) } // Reset navigation to initial state resetNavigation() } } /** * Start the navigation along the provided route using the [routeResult] and * collects updates in the location using the MapView's location display. * */ fun startNavigation() { // Set up a simulated location data source which simulates movement along the route val simulationParameters = SimulationParameters( startTime = Instant.now(), velocity = 35.0, horizontalAccuracy = 5.0, verticalAccuracy = 5.0 ) // Create the simulated data source using the polyline geometry and parameters val simulatedLocationDataSource = SimulatedLocationDataSource( polyline = simulationPolyline, parameters = simulationParameters ) // Set up a RouteTracker for navigation along the calculated route val routeTracker = routeResult?.let { RouteTracker( routeResult = it, routeIndex = 0, skipCoincidentStops = true ).apply { setSpeechEngineReadyCallback { isTextToSpeechInitialized && textToSpeech?.isSpeaking == false } } } ?: return messageDialogVM.showMessageDialog("Error retrieving route result") // Manage the job which triggers the location display locationDisplayJob = with(viewModelScope) { launch { // Check if this route task supports rerouting if (routeTask.getRouteTaskInfo().supportsRerouting) { // Set up the re-routing parameters val reroutingParameters = ReroutingParameters( routeTask = routeTask, routeParameters = routeParameters ).apply { strategy = ReroutingStrategy.ToNextWaypoint visitFirstStopOnStart = false } // Enable automatic re-routing routeTracker.enableRerouting(parameters = reroutingParameters) .onFailure { return@launch messageDialogVM.showMessageDialog(it) } } // Create a route tracker location data source to snap the location display to the route val routeTrackerLocationDataSource = RouteTrackerLocationDataSource( routeTracker = routeTracker, locationDataSource = simulatedLocationDataSource ) locationDisplay.apply { // Set the simulated location data source as the location data source for this app dataSource = routeTrackerLocationDataSource.also { // Start the location data source it.start().onFailure { return@launch messageDialogVM.showMessageDialog(it) } } // Set the auto pan to navigation mode setAutoPanMode(LocationDisplayAutoPanMode.Navigation) } // Plays the direction voice guidance updateVoiceGuidance(routeTracker) // Zoom in the scale to focus on the navigation route mapViewProxy.setViewpointScale(10000.0) } launch { // Listen for changes in location locationDisplay.location.collect { // Get the route's tracking status val trackingStatus = routeTracker.trackingStatus.value ?: return@collect // Displays the remaining and traversed route updateRouteGraphics(trackingStatus) // Display route status and directions info displayRouteInfo(trackingStatus) // Disable navigation button isNavigateButtonEnabled = false } } launch { // Automatically enable recenter button when navigation pan is disabled locationDisplay.autoPanMode.filter { it == LocationDisplayAutoPanMode.Off } .collect { isRecenterButtonEnabled = true } } launch { routeTracker.rerouteStarted.collect { nextDirectionText = "Re-routing..." } } } } /** * Displays the route distance and time information using [trackingStatus]. * When destination is reached the location data source is stopped. */ private suspend fun displayRouteInfo(trackingStatus: TrackingStatus) { // Get remaining distance information val remainingDistance = trackingStatus.destinationProgress.remainingDistance val remainingDistanceValue = remainingDistance.displayText val remainingDistanceUnits = remainingDistance.displayTextUnits.abbreviation // Convert remaining minutes to hours:minutes:seconds val remainingTimeString = DateUtils.formatElapsedTime( (trackingStatus.destinationProgress.remainingTime * 60).toLong() ) // Update text views timeRemainingText = remainingTimeString distanceRemainingText = "$remainingDistanceValue $remainingDistanceUnits" // If the destination has been reached if (trackingStatus.destinationStatus == DestinationStatus.Reached) { // Stop the location data source locationDisplay.dataSource.stop() } } /** * Update the remaining and traveled route graphics using [trackingStatus] */ private fun updateRouteGraphics(trackingStatus: TrackingStatus) { trackingStatus.routeProgress.let { // Set geometries for the route ahead and the remaining route routeAheadGraphic.geometry = it.remainingGeometry routeTraveledGraphic.geometry = it.traversedGeometry } } /** * Initialize and add route travel graphics to the map using [routeResult]'s [Polyline] geometry. */ private fun createRouteGraphics() { // Clear any graphics from the current graphics overlay graphicsOverlay.graphics.clear() // Set the view point to show the whole route val routeGeometry = routeResult?.routes?.get(0)?.routeGeometry // Set the geometry of the route ahead to the solved route geometry routeAheadGraphic.geometry = routeGeometry // Create the start and stop marker graphics val startGraphic = Graphic( geometry = startingStop.geometry, symbol = SimpleMarkerSymbol( style = SimpleMarkerSymbolStyle.Cross, color = Color.green, size = 20f ) ) val destinationGraphic = Graphic( geometry = destinationStop.geometry, symbol = SimpleMarkerSymbol( style = SimpleMarkerSymbolStyle.X, color = Color.red, size = 20f ) ) // Add the graphics to the graphics overlays graphicsOverlay.graphics.addAll( listOf(routeAheadGraphic, routeTraveledGraphic, startGraphic, destinationGraphic) ) } /** * Resets the navigation back to the initial state by stopping the * [locationDisplay]'s datasource and cancels related coroutine tasks. */ fun resetNavigation() { // Reset the navigation if button is clicked viewModelScope.launch { if (locationDisplayJob?.isActive == true) { // Stop location data sources locationDisplay.dataSource.stop() // Reset location display auto-pan-mode locationDisplay.setAutoPanMode(LocationDisplayAutoPanMode.Off) // Cancel the coroutine job locationDisplayJob?.cancelAndJoin() } // Set the map view view point to show the whole route routeResult?.routes?.get(0)?.routeGeometry?.extent?.let { mapViewProxy.setViewpointGeometry(it, 50.0) } mapViewProxy.setViewpointRotation(0.0) createRouteGraphics() isNavigateButtonEnabled = true textToSpeech?.stop() } } /** * Uses Android's [textToSpeech] to speak to say the latest * voice guidance from the [routeTracker] out loud. */ private suspend fun updateVoiceGuidance(routeTracker: RouteTracker) { // Listen for new voice guidance events routeTracker.newVoiceGuidance.collect { voiceGuidance -> // Use Android's text to speech to speak the voice guidance textToSpeech?.speak(voiceGuidance.text, TextToSpeech.QUEUE_FLUSH, null, null) // Set next direction text nextDirectionText = voiceGuidance.text } } fun recenterNavigation() { locationDisplay.setAutoPanMode(LocationDisplayAutoPanMode.Navigation) isRecenterButtonEnabled = false } private fun getColorArgb(id: Int): Int { return ContextCompat.getColor(getApplication(), id) } }