Navigation simulation on a downloaded map

In this guide you will learn how to simulate offline navigation along a route on a previously downloaded map.

Setup

First, get an API key token, see the Getting Started guide.

Download the Maps & Navigation SDK for Android archive file

Download the DownloadedOnboardMapSimulation project archive file or clone the project with Git

See the Configure Android Example guide.

Run the example

In Android Studio, from the File menu, select Sync Project with Gradle Files

An android device should be connected via USB cable.

Press SHIFT+F10 to compile, install and run the example on the android device.

Simulates offline navigation along a route on a previously downloaded map.

How it works

You can open the MainActivity.kt file to see how the local previously downloaded offline map is used for simulated navigation.

<uses-permission android:name="android.permission.INTERNET" />

Note that, in AndroidManifest.xml, the INTERNET permission is NOT present, as this example uses an offline map.

The previously downloaded map is stored on the device in a directory such as this: /sdcard/Android/data/com.magiclane.examplename/files/Data/Maps/.

private val navigationService = NavigationService()

A NavigationService() is instantiated, which carries out both simulated navigation and real navigation.

private val navigationListener: NavigationListener
= NavigationListener.create(
     onNavigationStarted = {
         SdkCall.execute {
             gemSurfaceView.mapView?.let { mapView ->
                 mapView.preferences?.enableCursor = false
                 navRoute?.let { route ->
                     mapView.presentRoute(route)
                 }
                 enableGPSButton()
                 mapView.followPosition()
             }
         }
         topPanel.visibility = View.VISIBLE
         bottomPanel.visibility = View.VISIBLE
         showStatusMessage("Simulation started.")
     },
     onNavigationInstructionUpdated = { instr ->
         var instrText = ""
         var instrIcon: Bitmap? = null
         var instrDistance = ""
         var etaText = ""
         var rttText = ""
         var rtdText = ""
         SdkCall.execute {
             // Fetch data for the navigation top panel (instruction related info).
             instrText = instr.nextStreetName ?: ""
             instrIcon = instr.nextTurnImage?.asBitmap(100, 100)
             instrDistance = instr.getDistanceInMeters()
             // Fetch data for the navigation bottom panel (route related info).
             navRoute?.apply {
                 etaText = getEta() // estimated time of arrival
                 rttText = getRtt() // remaining travel time
                 rtdText = getRtd() // remaining travel distance
             }
         }
         // Update the navigation panels info.
         navInstruction.text = instrText
         navInstructionIcon.setImageBitmap(instrIcon)
         navInstructionDistance.text = instrDistance
         eta.text = etaText
         rtt.text = rttText
         rtd.text = rtdText
         if (statusText.isVisible)
         {
             statusText.visibility = View.GONE
         }
     }
)

Define a navigation listener, navigationListener, that will receive notifications from the navigation service. The onNavigationStarted and onNavigationInstructionUpdated callbacks are implemented.

The navigation instructions received include a text instruction, such as “turn left”, a bitmap image, such as an arrow, and a distance, indicating how far ahead the turn is located.

navInstruction.text = instrText

navInstructionIcon.setImageBitmap(instrIcon)

navInstructionDistance.text = instrDistance

Additionally, the ETA, RTT and RTD are also obtained from the navigation service and displayed:

eta.text = // estimated time of arrival

rtt.text = // remaining travel time

rtd.text = // remaining travel distance

private val routingProgressListener = ProgressListener.create(
     onStarted = {
         progressBar.visibility = View.VISIBLE
         showStatusMessage("Routing process started.")
     },
     onCompleted = { _, _ ->
         progressBar.visibility = View.GONE
         showStatusMessage("Routing process completed.")
     },
     postOnMain = true
)

Define a listener to indicate when the route computation is completed, so real or simulated navigation (simulated in this case) can start.

override fun onCreate(savedInstanceState: Bundle?)
{
     super.onCreate(savedInstanceState)
     setContentView(R.layout.activity_main)
     gemSurfaceView = findViewById(R.id.gem_surface)
     progressBar = findViewById(R.id.progressBar)
     followCursorButton = findViewById(R.id.followCursor)
     topPanel = findViewById(R.id.top_panel)
     navInstruction = findViewById(R.id.nav_instruction)
     navInstructionDistance = findViewById(R.id.instr_distance)
     navInstructionIcon = findViewById(R.id.nav_icon)
     statusText = findViewById(R.id.status_text)
     bottomPanel = findViewById(R.id.bottom_panel)
     eta = findViewById(R.id.eta)
     rtt = findViewById(R.id.rtt)
     rtd = findViewById(R.id.rtd)
     SdkSettings.onApiTokenRejected = {
         showDialog("TOKEN REJECTED")
     }
     gemSurfaceView.onSdkInitSucceeded = {
         // Defines an action that should be done when the the sdk had been loaded.
         startSimulation()
     }
}

The MainActivity overrides the onCreate() function which gets the IDs of the 6 elements on the top and bottom panels to display the notifications from the navigation service:

text instructions, arrow bitmap image, distance to the instruction event, estimated time of arrival (ETA), remaining travel time (RTT) and remaining travel distance (RTD).

If the SDK initialization succeeded, the navigation simulation is started: startSimulation()

private fun enableGPSButton() {
     // Set actions for entering/ exiting following position mode.
     gemSurfaceView.mapView?.apply {
         onExitFollowingPosition = {
             followCursorButton.visibility = View.VISIBLE
         }
         onEnterFollowingPosition = {
             followCursorButton.visibility = View.GONE
         }
         // Set on click action for the GPS button.
         followCursorButton.setOnClickListener {
             SdkCall.execute { followPosition() }
         }
     }
}

enableGPSButton() causes a round purple button to appear in the lower right corner of the screen, whenever the simulation is active and the camera is not following the green arrow. If the user pushes this button, the followPosition() function is called, and thus the camera starts to follow the green arrow once again.

private fun startSimulation() = SdkCall.execute {
     val waypoints = arrayListOf(
         Landmark("Luxembourg", 49.61588784436375, 6.135843869736401),
         Landmark("Mersch", 49.74785494642988, 6.103323786692679)
     )
     navigationService.startSimulation(
         waypoints,
         navigationListener,
         routingProgressListener
     )
 }

The startSimulation() function first instantiates a list of 2 waypoints, one for the departure location and one for the destination; there can be more than 2 waypoints in a route, but not less than 2. These 2 waypoints are hardcoded here to locations within Luxembourg, because the offline map that is found in the app/assets/offlinemaps directory of this example, is of Luxembourg.

This example is configured to run offline (internet permission is not set) so no additional data will be downloaded - the route computation and navigation simulation will be completely offline, using the map data included with this example. This is why the departure and destination are within the area of the map that is stored offline for this example.

Android Examples

Maps SDK for Android Examples can be downloaded or cloned with Git