Location Data Sources

In this tutorial we will show how you can build a custom Location Source, representing locations of robot vacuums. The robots locations will be served from a mocked list and displayed on a map.

We will start by creating our implementation of a location source.

Create the class RobotVacuumLocationSource that implements MPLocationSource:

Implement the methods from MPLocationSource and extend the constructor of the RobotVacuumLocationSource to accept a list of locations that will represent the Robot vacuums.

class RobotVacuumLocationSource(private val robots: ArrayList<MPLocation>): MPLocationSource {
    private val mObservers = ArrayList<MPLocationsObserver>()
    private var mStatus = MPLocationSourceStatus.NOT_INITIALIZED
    override fun getLocations(): MutableList<MPLocation> {
        return robots
    }
    override fun addLocationsObserver(observer: MPLocationsObserver?) {
        if (observer != null) {
            mObservers.add(observer)
        }
    }
    override fun removeLocationsObserver(observer: MPLocationsObserver?) {
        if (observer != null) {
            mObservers.remove(observer)
        }
    }
    private fun notifyUpdateLocations() {
        for (observer in mObservers) {
            observer.onLocationsUpdated(robots, this)
        }
    }
    override fun getStatus(): MPLocationSourceStatus {
        return mStatus
    }
    override fun getSourceId(): Int {
        return 10101010
    }
    override fun clearCache() {
        robots.clear()
        mObservers.clear()
    }
    override fun terminate() {
        robots.clear()
        mObservers.clear()
    }
}

Create a Fragment or Activity that contains a map with MapsIndoors loaded.

Add a BASE_POSITION MPLatLng that will be used to calculate a random location for the Robot Vacuums.

private val BASE_POSITION = MPLatLng(57.0582502, 9.9504788)

Then we need to add some variables:

private var baseDisplayRule: WeakReference<MPDisplayRule?>? = null
private var robotDisplayRule: MPDisplayRule? = null
private var mLocations: ArrayList<MPLocation>? = null
private var mRobotVacuumLocationSource: RobotVacuumLocationSource? = null

Create the baseDisplayRule after MapsIndoors has loaded:

MapsIndoors.load(requireActivity().applicationContext, "MY_API_KEY") { error ->
    if (error == null) {
        baseDisplayRule = WeakReference(MapsIndoors.getMainDisplayRule())
        setupLocationSource()
    }
}

create a method to setup the RobotVacuumLocationSource inside your fragment:

private fun setupLocationSource() {
    if (mLocations == null) {
        generateLocations()
    }
    val locationSource = RobotVacuumLocationSource(mLocations!!)
    MapsIndoors.addLocationSources(Collections.singletonList(locationSource) as List<MPLocationSource>) {
    }
    locationSource.setup()
    startUpdatingPositions()
}

As seen in the example above we add the RobotVacuumLocationSource through MapsIndoors.addLocationSources and call RobotVacuumLocationSource.setup()

This method sets the status to of the source to available and notifies MapsIndoors that locations are updated.

fun setup() {
    status = MPLocationSourceStatus.AVAILABLE
    notifyUpdateLocations()
}
fun setStatus(status: MPLocationSourceStatus) {
    mStatus = status
    for (observer in mObservers) {
        observer.onStatusChanged(mStatus, this)
    }
}

In the setupLocationSource method we call generateLocations to populate the location list with new locations:

private fun generateLocations() {
    mLocations = ArrayList()
    for (i in 0..15) {
        val robotName = "vacuum$i"
        val startPosition = getRandomPosition()
        val charge = nextInt(1, 100)
        val floorIndex = nextInt(4) * 10
        var mpLocation = MPLocation.Builder(robotName)
            .setPosition(startPosition.lat, startPosition.lng)
            .setFloorIndex(floorIndex)
            .setName(robotName)
            .setBuilding("Stigsborgvej")
            .build()
        robotDisplayRule = MPDisplayRule(robotName, baseDisplayRule!!)
        robotDisplayRule?.isVisible = true
        if (charge >= 60) {
            robotDisplayRule?.setIcon(R.drawable.ic_baseline_robo_vacuum, Color.GREEN)
        }else if (charge >= 30) {
            robotDisplayRule?.setIcon(R.drawable.ic_baseline_robo_vacuum, Color.YELLOW)
        }else {
            robotDisplayRule?.setIcon(R.drawable.ic_baseline_robo_vacuum, Color.RED)
        }
        MapsIndoors.addDisplayRuleForLocation(mpLocation, robotDisplayRule!!)
        mLocations?.add(mpLocation)
    }
}
private fun getRandomPosition(): MPLatLng {
    val lat: Double = BASE_POSITION.lat + (-4 + nextInt(20)) * 0.000005
    val lng: Double = BASE_POSITION.lng + (-4 + nextInt(20)) * 0.000010
    return MPLatLng(lat, lng)
}

Create the startUpdatingPositions method that calls updateLocations every second:

private fun startUpdatingPositions() {
    mUpdateTimer?.cancel()
    mUpdateTimer = Timer()
    mUpdateTimer?.scheduleAtFixedRate(object: TimerTask() {
        override fun run() {
            updateLocations();
        }
    }, 2000, 500)
}

Create a method that can stop the positions updates at any time:

fun stopUpdatingPositions() {
    mUpdateTimer?.cancel()
    mUpdateTimer?.purge()
}

Create a method called updateLocations that will update the position of the Locations:

fun updateLocations() {
    var updatedLocations = ArrayList<MPLocation>()
    mLocations?.forEach {
        var newPosition = getRandomPosition()
        var newLocation = MPLocation.Builder(it).setPosition(MPPoint(newPosition.lat, newPosition.lng), 20)
        var charge = nextInt(1, 100)
        updatedLocations.add(newLocation.build())
        robotDisplayRule = MPDisplayRule("robot", baseDisplayRule!!)
        robotDisplayRule?.isVisible = true
        if (charge >= 60) {
            robotDisplayRule?.setIcon(R.drawable.ic_baseline_robo_vacuum, Color.GREEN)
        }else if (charge >= 30) {
            robotDisplayRule?.setIcon(R.drawable.ic_baseline_robo_vacuum, Color.YELLOW)
        }else {
            robotDisplayRule?.setIcon(R.drawable.ic_baseline_robo_vacuum, Color.RED)
        }
        MapsIndoors.addDisplayRuleForLocation(it, robotDisplayRule!!)
    }
    mRobotVacuumLocationSource?.updateLocations(updatedLocations)
}

See the samples in the locationsources folder