Add Markers in Bulk

This example demonstrates how you can add markers in bulk.

class BulkMarkerActivity : AppCompatActivity(), OnItemSelectedListener {
    private lateinit var mapMetricsMap: MapMetricsMap
    private lateinit var mapView: MapView
    private var locations: List<LatLng>? = null
    private var progressDialog: ProgressDialog? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_marker_bulk)
        mapView = findViewById(R.id.mapView)
        mapView.onCreate(savedInstanceState)
        mapView.getMapAsync { initMap(it) }
    }

    private fun initMap(mapMetricsMap: MapMetricsMap) {
        this.mapMetricsMap = mapMetricsMap
        mapMetricsMap.setStyle(TestStyles.getPredefinedStyleWithFallback("Streets"))
    }

    override fun onCreateOptionsMenu(menu: Menu): Boolean {
        val spinnerAdapter = ArrayAdapter.createFromResource(
            this,
            R.array.bulk_marker_list,
            android.R.layout.simple_spinner_item
        )
        spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
        menuInflater.inflate(R.menu.menu_bulk_marker, menu)
        val item = menu.findItem(R.id.spinner)
        val spinner = item.actionView as Spinner
        spinner.adapter = spinnerAdapter
        spinner.onItemSelectedListener = this@BulkMarkerActivity
        return true
    }

    override fun onItemSelected(parent: AdapterView<*>?, view: View, position: Int, id: Long) {
        val amount = Integer.valueOf(resources.getStringArray(R.array.bulk_marker_list)[position])
        if (locations == null) {
            progressDialog = ProgressDialog.show(this, "Loading", "Fetching markers", false)
            lifecycleScope.launch(Dispatchers.IO) {
                locations = loadLocationTask(this@BulkMarkerActivity)
                withContext(Dispatchers.Main) {
                    onLatLngListLoaded(locations, amount)
                }
            }
        } else {
            showMarkers(amount)
        }
    }

    private fun onLatLngListLoaded(latLngs: List<LatLng>?, amount: Int) {
        progressDialog!!.hide()
        locations = latLngs
        showMarkers(amount)
    }

    private fun showMarkers(amount: Int) {
        if (!this::mapMetricsMap.isInitialized || locations == null || mapView.isDestroyed) {
            return
        }
        mapMetricsMap.clear()
        showGlMarkers(min(amount, locations!!.size))
    }

    private fun showGlMarkers(amount: Int) {
        val markerOptionsList: MutableList<MarkerOptions> = ArrayList()
        val formatter = DecimalFormat("#.#####")
        val random = Random()
        var randomIndex: Int
        for (i in 0 until amount) {
            randomIndex = random.nextInt(locations!!.size)
            val latLng = locations!![randomIndex]
            markerOptionsList.add(
                MarkerOptions()
                    .position(latLng)
                    .title(i.toString())
                    .snippet(formatter.format(latLng.latitude) + "`, " + formatter.format(latLng.longitude))
            )
        }
        mapMetricsMap.addMarkers(markerOptionsList)
    }

    override fun onNothingSelected(parent: AdapterView<*>?) {
        // nothing selected, nothing to do!
    }

    override fun onStart() {
        super.onStart()
        mapView.onStart()
    }

    override fun onResume() {
        super.onResume()
        mapView.onResume()
    }

    override fun onPause() {
        super.onPause()
        mapView.onPause()
    }

    override fun onStop() {
        super.onStop()
        mapView.onStop()
    }

    override fun onSaveInstanceState(outState: Bundle) {
        super.onSaveInstanceState(outState)
        mapView.onSaveInstanceState(outState)
    }

    override fun onDestroy() {
        super.onDestroy()
        if (progressDialog != null) {
            progressDialog!!.dismiss()
        }
        mapView.onDestroy()
    }

    override fun onLowMemory() {
        super.onLowMemory()
        mapView.onLowMemory()
    }

    private fun loadLocationTask(
        activity: BulkMarkerActivity,
    ) : List<LatLng>? {
        try {
            val json = GeoParseUtil.loadStringFromAssets(
                activity.applicationContext,
                "points.geojson"
            )
            return GeoParseUtil.parseGeoJsonCoordinates(json)
        } catch (exception: IOException) {
            Timber.e(exception, "Could not add markers")
        }
        return null
    }
}