Navigate route

View on GitHub

Sample viewer app

Use a routing service to navigate between two points.

Image of navigate route

Use case

Navigation is often used by field workers while traveling between two points to get live directions based on their location.

How to use the sample

Tap "Navigate" to simulate traveling and to receive directions from a preset starting point to a preset destination. Tap "Reset" to start the simulation from the beginning.

How it works

Create an AGSRouteTask using a URL to an online route service.
Generate default AGSRouteParameters using AGSRouteTask.defaultRouteParameters(completion:).
Set returnRoutes, returnStops, and returnDirections on the parameters to true.
Assign all AGSStop objects to the route parameters using AGSRouteParameters.setStops(_:).
Solve the route using AGSRouteTask.solveRoute(with:completion:) to get an AGSRouteResult.
Create an AGSRouteTracker using the route result, and the index of the desired route to take.
Create an AGSRouteTrackerLocationDataSource with the route tracker and an AGSSimulatedLocationDataSource object to snap the location display to the route.
Use AGSLocationChangeHandlerDelegate.locationDataSource(_:locationDidChange:) to track the location of the device and update the route tracking status.
Use AGSRouteTrackerDelegate.routeTracker(_:didUpdate:) to be notified of AGSTrackingStatus changes, and use them to display updated route information. AGSTrackingStatus includes a variety of information on the route progress, such as the remaining distance, remaining geometry or traversed geometry (represented by an AGSPolyline), or the remaining time (Double), amongst others.
Use AGSRouteTrackerDelegate.routeTracker(_:didGenerateNewVoiceGuidance:) to be notified of new voice guidances. From the voice guidance, get the AGSVoiceGuidance.text representing the directions and use a text-to-speech engine to output the maneuver directions.
You can also query the tracking status for the current AGSDirectionManeuver index, retrieve that maneuver from the AGSRoute, and get its direction text to display in the GUI.
To establish whether the destination has been reached, get the destinationStatus from the tracking status. If the destination status is reached and the remainingDestinationCount is 1, you have arrived at the destination and can stop routing. If there are several destinations on your route and the remaining destination count is greater than 1, switch the route tracker to the next destination.

Relevant API

AGSDestinationStatus
AGSDirectionManeuver
AGSLocation
AGSLocationDataSource
AGSRoute
AGSRouteParameters
AGSRouteTask
AGSRouteTracker
AGSRouteTrackerLocationDataSource
AGSSimulatedLocationDataSource
AGSStop
AGSVoiceGuidance

About the data

The 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.

Sample Code

NavigateRouteViewController.swift
Use dark colors for code blocksCopy
// Copyright 2020 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.

import UIKit
import AVFoundation
import ArcGIS

// MARK: - Navigate route View Controller

class NavigateRouteViewController: UIViewController {
    // MARK: Storyboard views

    /// The label to display navigation status.
    @IBOutlet var statusLabel: UILabel!
    /// The button to start navigation.
    @IBOutlet var navigateBarButtonItem: UIBarButtonItem!
    /// The button to reset navigation.
    @IBOutlet var resetBarButtonItem: UIBarButtonItem!
    /// The button to recenter the map to navigation pan mode.
    @IBOutlet var recenterBarButtonItem: UIBarButtonItem!
    /// The map view managed by the view controller.
    @IBOutlet var mapView: AGSMapView! {
        didSet {
            mapView.map = AGSMap(basemapStyle: .arcGISNavigation)
            mapView.graphicsOverlays.add(makeRouteOverlay())
        }
    }

    // MARK: Instance properties

    /// The route task to solve the route between stops, using the online routing service.
    let routeTask = AGSRouteTask(url: URL(string: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/NetworkAnalysis/SanDiego/NAServer/Route")!)
    /// The route result solved by the route task.
    var routeResult: AGSRouteResult!
    /// The route tracker for navigation. Use delegate methods to update tracking status.
    var routeTracker: AGSRouteTracker!
    /// A list to keep track of directions solved by the route task.
    var directionsList: [AGSDirectionManeuver] = []

    /// The original view point that can be reset later on.
    var defaultViewPoint: AGSViewpoint?
    /// The initial location for the solved route.
    var initialLocation: AGSLocation!

    /// The graphic (with a dashed line symbol) to represent the route ahead.
    let routeAheadGraphic = AGSGraphic(geometry: nil, symbol: AGSSimpleLineSymbol(style: .dash, color: .systemPurple, width: 5))
    /// The graphic to represent the route that's been traveled (initially empty).
    let routeTraveledGraphic = AGSGraphic(geometry: nil, symbol: AGSSimpleLineSymbol(style: .solid, color: .systemBlue, width: 3))
    /// A formatter to format a time value into human readable string.
    let timeFormatter: DateComponentsFormatter = {
        let formatter = DateComponentsFormatter()
        formatter.allowedUnits = [.hour, .minute, .second]
        formatter.unitsStyle = .full
        return formatter
    }()
    /// An AVSpeechSynthesizer for text to speech.
    let speechSynthesizer = AVSpeechSynthesizer()

    // MARK: Instance methods

    /// A wrapper function for operations after the route is solved by an `AGSRouteTask`.
    ///
    /// - Parameter routeResult: The result from `AGSRouteTask.solveRoute(with:completion:)`.
    func didSolveRoute(with routeResult: Result<AGSRouteResult, Error>) {
        switch routeResult {
        case .success(let routeResult):
            self.routeResult = routeResult
            setNavigation(with: routeResult)
            navigateBarButtonItem.isEnabled = true
        case .failure(let error):
            presentAlert(error: error)
            setStatus(message: "Failed to solve route.")
            navigateBarButtonItem.isEnabled = false
        }
    }

    /// Create the stops for the navigation.
    ///
    /// - Returns: An array of `AGSStop` objects.
    func makeStops() -> [AGSStop] {
        let stop1 = AGSStop(point: AGSPoint(x: -117.160386727, y: 32.706608, spatialReference: .wgs84()))
        stop1.name = "San Diego Convention Center"
        let stop2 = AGSStop(point: AGSPoint(x: -117.173034, y: 32.712329, spatialReference: .wgs84()))
        stop2.name = "USS San Diego Memorial"
        let stop3 = AGSStop(point: AGSPoint(x: -117.147230, y: 32.730467, spatialReference: .wgs84()))
        stop3.name = "RH Fleet Aerospace Museum"
        return [stop1, stop2, stop3]
    }

    /// Make the simulated data source for this demo.
    ///
    /// - Parameter route: An `AGSRoute` object whose geometry is used to configure the data source.
    /// - Returns: An `AGSSimulatedLocationDataSource` object.
    func makeDataSource(route: AGSRoute) -> AGSSimulatedLocationDataSource {
        let densifiedRoute = AGSGeometryEngine.geodeticDensifyGeometry(route.routeGeometry!, maxSegmentLength: 50.0, lengthUnit: .meters(), curveType: .geodesic) as! AGSPolyline
        // The mock data source to demo the navigation. Use delegate methods to update locations for the tracker.
        let mockDataSource = AGSSimulatedLocationDataSource()
        mockDataSource.setLocationsWith(densifiedRoute)
        mockDataSource.locationChangeHandlerDelegate = self
        return mockDataSource
    }

    /// Make a route tracker to provide navigation information.
    ///
    /// - Parameter result: An `AGSRouteResult` object used to configure the route tracker.
    /// - Returns: An `AGSRouteTracker` object.
    func makeRouteTracker(result: AGSRouteResult) -> AGSRouteTracker {
        let tracker = AGSRouteTracker(routeResult: result, routeIndex: 0, skipCoincidentStops: true)!
        tracker.delegate = self
        tracker.voiceGuidanceUnitSystem = Locale.current.usesMetricSystem ? .metric : .imperial
        return tracker
    }

    /// Make a graphics overlay with graphics.
    ///
    /// - Returns: An `AGSGraphicsOverlay` object.
    func makeRouteOverlay() -> AGSGraphicsOverlay {
        // The graphics overlay for the polygon and points.
        let graphicsOverlay = AGSGraphicsOverlay()
        let stopSymbol = AGSSimpleMarkerSymbol(style: .diamond, color: .orange, size: 20)
        let stopGraphics = makeStops().map { AGSGraphic(geometry: $0.geometry, symbol: stopSymbol) }
        let routeGraphics = [routeAheadGraphic, routeTraveledGraphic]
        // Add graphics to the graphics overlay.
        graphicsOverlay.graphics.addObjects(from: routeGraphics + stopGraphics)
        return graphicsOverlay
    }

    /// Update the viewpoint so that it reflects the original viewpoint when the example is loaded.
    ///
    /// - Parameter result: An `AGSGeometry` object used to update the view point.
    func updateViewpoint(geometry: AGSGeometry) {
        // Show the resulting route on the map and save a reference to the route.
        if let viewPoint = defaultViewPoint {
            // Reset to initial view point with animation.
            mapView.setViewpoint(viewPoint, completion: nil)
        } else {
            mapView.setViewpointGeometry(geometry) { [weak self] _ in
                // Get the initial zoomed view point.
                self?.defaultViewPoint = self?.mapView.currentViewpoint(with: .centerAndScale)
            }
        }
    }

    /// Set route tracker, data source and location display with a solved route result.
    ///
    /// - Parameter routeResult: An `AGSRouteResult` object.
    func setNavigation(with routeResult: AGSRouteResult) {
        // Set the route tracker
        routeTracker = makeRouteTracker(result: routeResult)

        // Set the mock location data source.
        let firstRoute = routeResult.routes.first!
        directionsList = firstRoute.directionManeuvers
        let mockDataSource = makeDataSource(route: firstRoute)
        initialLocation = mockDataSource.locations?.first
        // Create a route tracker location data source to snap the location display to the route.
        let routeTrackerLocationDataSource = AGSRouteTrackerLocationDataSource(routeTracker: routeTracker, locationDataSource: mockDataSource)

        // Set location display.
        mapView.locationDisplay.dataSource = routeTrackerLocationDataSource
        recenter()

        // Update graphics and viewpoint.
        let firstRouteGeometry = firstRoute.routeGeometry!
        updateRouteGraphics(remaining: firstRouteGeometry)
        updateViewpoint(geometry: firstRouteGeometry)
    }

    // MARK: UI

    func setStatus(message: String) {
        statusLabel.text = message
    }

    // MARK: Actions

    /// Called in response to the "Navigate" button being tapped.
    @IBAction func startNavigation() {
        navigateBarButtonItem.isEnabled = false
        resetBarButtonItem.isEnabled = true
        // Start the location data source and location display.
        mapView.locationDisplay.start()
    }

    /// Called in response to the "Reset" button being tapped.
    @IBAction func reset() {
        // Stop the speech, if there is any.
        speechSynthesizer.stopSpeaking(at: .immediate)
        // Reset to the starting location for location display.
        mapView.locationDisplay.dataSource.didUpdate(initialLocation)
        // Stop the location display as well as datasource generation, if reset before the end is reached.
        mapView.locationDisplay.stop()
        mapView.locationDisplay.autoPanModeChangedHandler = nil
        mapView.locationDisplay.autoPanMode = .off
        directionsList.removeAll()
        setStatus(message: "Directions are shown here.")

        // Reset the navigation.
        setNavigation(with: routeResult)
        // Reset buttons state.
        resetBarButtonItem.isEnabled = false
        navigateBarButtonItem.isEnabled = true
    }

    /// Called in response to the "Recenter" button being tapped.
    @IBAction func recenter() {
        mapView.locationDisplay.autoPanMode = .navigation
        recenterBarButtonItem.isEnabled = false
        mapView.locationDisplay.autoPanModeChangedHandler = { [weak self] _ in
            DispatchQueue.main.async {
                self?.recenterBarButtonItem.isEnabled = true
            }
            self?.mapView.locationDisplay.autoPanModeChangedHandler = nil
        }
    }

    // MARK: UIViewController

    override func viewDidLoad() {
        super.viewDidLoad()
        // Add the source code button item to the right of navigation bar.
        (navigationItem.rightBarButtonItem as? SourceCodeBarButtonItem)?.filenames = ["NavigateRouteViewController"]
        // Avoid the overlap between the status label and the map content.
        mapView.contentInset.top = CGFloat(statusLabel.numberOfLines) * statusLabel.font.lineHeight

        // Solve the route as map loads.
        routeTask.defaultRouteParameters { [weak self] (params: AGSRouteParameters?, error: Error?) in
            guard let self = self else { return }
            if let params = params {
                // Explicitly set values for parameters.
                params.returnDirections = true
                params.returnStops = true
                params.returnRoutes = true
                params.outputSpatialReference = .wgs84()
                params.setStops(self.makeStops())
                self.routeTask.solveRoute(with: params) { [weak self] (result, error) in
                    if let result = result {
                        self?.didSolveRoute(with: .success(result))
                    } else if let error = error {
                        self?.didSolveRoute(with: .failure(error))
                    }
                }
            } else if let error = error {
                self.presentAlert(error: error)
                self.setStatus(message: "Failed to get route parameters.")
            }
        }
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        // Only reset when the route is successfully solved.
        if routeResult != nil {
            reset()
        }
    }
}

// MARK: - AGSRouteTrackerDelegate

extension NavigateRouteViewController: AGSRouteTrackerDelegate {
    func routeTracker(_ routeTracker: AGSRouteTracker, didGenerateNewVoiceGuidance voiceGuidance: AGSVoiceGuidance) {
        setSpeakDirection(with: voiceGuidance.text)
    }

    func routeTracker(_ routeTracker: AGSRouteTracker, didUpdate trackingStatus: AGSTrackingStatus) {
        updateTrackingStatusDisplay(routeTracker: routeTracker, status: trackingStatus)
    }

    func setSpeakDirection(with text: String) {
        speechSynthesizer.stopSpeaking(at: .word)
        speechSynthesizer.speak(AVSpeechUtterance(string: text))
    }

    func updateTrackingStatusDisplay(routeTracker: AGSRouteTracker, status: AGSTrackingStatus) {
        var statusText: String
        switch status.destinationStatus {
        case .notReached, .approaching:
            let distanceRemaining = status.routeProgress.remainingDistance.displayText + " " + status.routeProgress.remainingDistance.displayTextUnits.abbreviation
            let timeRemaining = timeFormatter.string(from: TimeInterval(status.routeProgress.remainingTime * 60))!
            statusText = """
            Distance remaining: \(distanceRemaining)
            Time remaining: \(timeRemaining)
            """
            if status.currentManeuverIndex + 1 < directionsList.count {
                let nextDirection = directionsList[status.currentManeuverIndex + 1].directionText
                statusText.append("\nNext direction: \(nextDirection)")
            }
        case .reached:
            if status.remainingDestinationCount > 1 {
                statusText = "Intermediate stop reached, continue to next stop."
                routeTracker.switchToNextDestination()
            } else {
                statusText = "Final destination reached."
                mapView.locationDisplay.stop()
            }
        default:
            return
        }
        updateRouteGraphics(remaining: status.routeProgress.remainingGeometry, traversed: status.routeProgress.traversedGeometry)
        setStatus(message: statusText)
    }

    func updateRouteGraphics(remaining: AGSGeometry?, traversed: AGSGeometry? = nil) {
        routeAheadGraphic.geometry = remaining
        routeTraveledGraphic.geometry = traversed
    }
}

// MARK: - AGSLocationChangeHandlerDelegate

extension NavigateRouteViewController: AGSLocationChangeHandlerDelegate {
    func locationDataSource(_ locationDataSource: AGSLocationDataSource, locationDidChange location: AGSLocation) {
        // Update the tracker location with the new location from the simulated data source.
        routeTracker?.trackLocation(location) { [weak self] error in
            guard let self = self else { return }
            if let error = error {
                // Display error message and stop further route tracking if it
                // fails due to data format, licensing issue, etc.
                self.setStatus(message: error.localizedDescription)
                self.routeTracker = nil
            }
        }
    }
}