Export tiles from an online vector tile service.
Use case
Field workers with limited network connectivity can use exported vector tiles as a basemap for use while offline.
How to use the sample
When the vector tiled layer loads, zoom in to the extent you want to export. The red box shows the extent that will be exported. Click the "Export Vector Tiles" button to start the job. An error will show if the extent is larger than the maximum limit allowed. When finished, a dialog will show the exported result in a new map view.
How it works
- Create an
ArcGISVectorTiledLayerfrom the map's base layers. - Create an
ExportVectorTilesTaskusing the vector tiled layer's URL. - Create default
ExportVectorTilesParametersfrom the task, specifying extent and maximum scale. - Create a
ExportVectorTilesJobfrom the task using the parameters, and specifying a vector tile cache path and an item resource path. The resource path is required if you want to export the tiles with the style. - Start the job, and once it completes successfully, get the resulting
ExportVectorTilesResult. - Get the
VectorTileCachefrom the result to create anArcGISVectorTiledLayerthat can be displayed to the map view.
Relevant API
- ArcGISVectorTiledLayer
- ExportVectorTilesJob
- ExportVectorTilesParameters
- ExportVectorTilesResult
- ExportVectorTilesTask
- VectorTileCache
Additional information
NOTE: Downloading Tiles for offline use requires authentication with the web map's server. To use this sample, you will require an ArcGIS Online account.
Vector tiles have high drawing performance and smaller file size compared to regular tiled layers, due to consisting solely of points, lines, and polygons. However, in ArcGIS Runtime SDK they cannot be displayed in scenes. Visit the ArcGiS Online Developer's portal to Learn more about the characteristics of ArcGIS vector tiled layers.
Tags
cache, download, offline, vector
Sample Code
MainActivity.kt
/* Copyright 2022 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.arcgisruntime.sample.exportvectortiles
import android.app.AlertDialog
import android.graphics.Color
import android.os.Bundle
import android.util.Log
import android.view.View
import android.widget.Button
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.constraintlayout.widget.ConstraintLayout
import com.esri.arcgisruntime.ArcGISRuntimeEnvironment
import com.esri.arcgisruntime.concurrent.Job
import com.esri.arcgisruntime.geometry.Envelope
import com.esri.arcgisruntime.layers.ArcGISVectorTiledLayer
import com.esri.arcgisruntime.loadable.LoadStatus
import com.esri.arcgisruntime.mapping.ArcGISMap
import com.esri.arcgisruntime.mapping.Basemap
import com.esri.arcgisruntime.mapping.BasemapStyle
import com.esri.arcgisruntime.mapping.Viewpoint
import com.esri.arcgisruntime.mapping.view.Graphic
import com.esri.arcgisruntime.mapping.view.GraphicsOverlay
import com.esri.arcgisruntime.mapping.view.MapView
import com.esri.arcgisruntime.sample.exportvectortiles.databinding.ActivityMainBinding
import com.esri.arcgisruntime.sample.exportvectortiles.databinding.ProgressDialogLayoutBinding
import com.esri.arcgisruntime.symbology.SimpleLineSymbol
import com.esri.arcgisruntime.tasks.vectortilecache.ExportVectorTilesJob
import com.esri.arcgisruntime.tasks.vectortilecache.ExportVectorTilesParameters
import com.esri.arcgisruntime.tasks.vectortilecache.ExportVectorTilesResult
import com.esri.arcgisruntime.tasks.vectortilecache.ExportVectorTilesTask
import java.io.File
class MainActivity : AppCompatActivity() {
private val TAG = MainActivity::class.java.simpleName
private var downloadArea: Graphic? = null
private var exportVectorTilesJob: ExportVectorTilesJob? = null
private var dialog: AlertDialog? = null
private var isJobFinished: Boolean = true
private val activityMainBinding by lazy {
ActivityMainBinding.inflate(layoutInflater)
}
private val mapView: MapView by lazy {
activityMainBinding.mapView
}
private val mapPreviewLayout: ConstraintLayout by lazy {
activityMainBinding.mapPreviewLayout
}
private val exportVectorTilesButton: Button by lazy {
activityMainBinding.exportVectorTilesButton
}
private val previewMapView: MapView by lazy {
activityMainBinding.previewMapView
}
private val dimBackground: View by lazy {
activityMainBinding.dimBackground
}
private val closeButton: Button by lazy {
activityMainBinding.closeButton
}
private val previewTextView: TextView by lazy {
activityMainBinding.previewTextView
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(activityMainBinding.root)
// authentication with an API key or named user is required to access basemaps and other
// location services
ArcGISRuntimeEnvironment.setApiKey(BuildConfig.API_KEY)
// create a graphic to show a red outline square around the vector tiles to be downloaded
downloadArea = Graphic().apply {
symbol = SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, Color.RED, 2F)
}
// create a graphics overlay and add the downloadArea graphic
val graphicsOverlay = GraphicsOverlay().apply {
graphics.add(downloadArea)
}
mapView.apply {
// set the map to BasemapType navigation night
map = ArcGISMap(BasemapStyle.ARCGIS_STREETS_NIGHT)
// disable rotation
rotation = 0F
// set the viewpoint of the sample to ESRI Redlands, CA campus
setViewpoint(Viewpoint(34.056295, -117.195800, 100000.0))
// add the graphics overlay to the MapView
graphicsOverlays.add(graphicsOverlay)
// update the red square whenever the viewpoint changes
addViewpointChangedListener {
updateDownloadAreaGeometry()
}
// when the map has loaded, create a vector tiled layer from the basemap and export the tiles
map.addDoneLoadingListener {
if (map.loadStatus == LoadStatus.LOADED) {
// check that the layer from the basemap is a vector tiled layer
val vectorTiledLayer = map.basemap.baseLayers[0] as ArcGISVectorTiledLayer
handleExportButton(vectorTiledLayer)
} else {
showError(map.loadError.message.toString())
}
}
}
}
/**
* Sets up the ExportVectorTilesTask using the [vectorTiledLayer]
* on export button click. Then call handleExportVectorTilesJob()
*/
private fun handleExportButton(vectorTiledLayer: ArcGISVectorTiledLayer) {
exportVectorTilesButton.setOnClickListener {
// update the download area's geometry using the current viewpoint
updateDownloadAreaGeometry()
// create a new export vector tiles task
val exportVectorTilesTask = ExportVectorTilesTask(vectorTiledLayer.uri)
// the max scale parameter is set to 10% of the map's scale so the
// number of tiles exported are within the vector tiled layer's max tile export limit
val exportVectorTilesParametersFuture = exportVectorTilesTask
.createDefaultExportVectorTilesParametersAsync(
downloadArea?.geometry,
mapView.mapScale * 0.1
)
exportVectorTilesParametersFuture.addDoneListener {
try {
// get the loaded export vector tile parameters
val exportVectorTilesParameters =
exportVectorTilesParametersFuture.get()
// only start a new job, if the previous job has finished cancelling
if(isJobFinished){
// create a job to export vector tiles
handleExportVectorTilesJob(
exportVectorTilesParameters,
exportVectorTilesTask
)
} else {
showError("Previous job is cancelling asynchronously")
}
} catch (e: Exception) {
showError(e.message.toString())
}
}
}
}
/**
* Start the export vector tiles job using [exportVectorTilesTask] and the
* [exportVectorTilesParameters]. The vector tile package is exported as "file.vtpk"
*/
private fun handleExportVectorTilesJob(
exportVectorTilesParameters: ExportVectorTilesParameters,
exportVectorTilesTask: ExportVectorTilesTask
) {
// create a .vtpk and directory in the app's cache for saving exported tiles
val vtpkFile = File(externalCacheDir, "/StyleItemResources/myVectorTiles.vtpk")
val resDir = File(externalCacheDir, "/StyleItemResources")
resDir.deleteRecursively()
resDir.mkdir()
// create a job with the export vector tile parameters
// and exports the vector tile package as "file.vtpk"
exportVectorTilesJob = exportVectorTilesTask.exportVectorTiles(
exportVectorTilesParameters,
vtpkFile.absolutePath, resDir.absolutePath
).apply {
// inflate the progress dialog
val dialogLayoutBinding = createProgressDialog()
// start the export vector tile cache job
start()
// since job is now started, set to false
isJobFinished = false
// display the progress dialog
dialog?.show()
// update the dialog using the progress of the job
addProgressChangedListener {
dialogLayoutBinding.progressBar.progress = progress
dialogLayoutBinding.progressTextView.text = "$progress% completed"
}
// on job done loading
addJobDoneListener {
dialog?.dismiss()
if (status == Job.Status.SUCCEEDED) {
// display the map preview using the result from the completed job
showMapPreview(result)
} else {
showError(error.message.toString())
isJobFinished = true
}
}
}
}
/**
* Updates the [downloadArea]'s geometry on ViewPoint change
* or when export tiles button is clicked.
*/
private fun updateDownloadAreaGeometry() {
try {
mapView.apply {
if (mapView.map.loadStatus == LoadStatus.LOADED) {
// upper left corner of the downloaded tile cache area
val minScreenPoint: android.graphics.Point = android.graphics.Point(150, 175)
// lower right corner of the downloaded tile cache area
val maxScreenPoint: android.graphics.Point = android.graphics.Point(
mapView.width - 150,
mapView.height - 250
)
// convert screen points to map points
val minPoint: com.esri.arcgisruntime.geometry.Point =
mapView.screenToLocation(minScreenPoint)
val maxPoint: com.esri.arcgisruntime.geometry.Point =
mapView.screenToLocation(maxScreenPoint)
// use the points to define and return an envelope
downloadArea?.geometry = Envelope(minPoint, maxPoint)
}
}
} catch (e: Exception) {
// Silently fail, since mapView has not been rendered yet.
}
}
/**
* Create a progress dialog to track the progress of the [exportVectorTilesJob]
*/
private fun createProgressDialog(): ProgressDialogLayoutBinding {
val dialogLayoutBinding = ProgressDialogLayoutBinding.inflate(layoutInflater)
val dialogBuilder = AlertDialog.Builder(this@MainActivity).apply {
setTitle("Exporting vector tiles")
setNegativeButton("Cancel job") { _, _ ->
// cancels the export job asynchronously
val future = exportVectorTilesJob?.cancelAsync()
future?.addDoneListener {
// cancel is completed, so set to true
isJobFinished = true
}
}
setCancelable(false)
setView(dialogLayoutBinding.root)
}
dialog = dialogBuilder.create()
return dialogLayoutBinding
}
/**
* Display the preview of the exported map using the
* [vectorTilesResult] from the completed job
*/
private fun showMapPreview(vectorTilesResult: ExportVectorTilesResult?) {
// get the layer exported for the preview MapView
val vectorTiledLayer = ArcGISVectorTiledLayer(
vectorTilesResult?.vectorTileCache,
vectorTilesResult?.itemResourceCache
)
// set up the preview MapView
previewMapView.apply {
map = ArcGISMap(Basemap(vectorTiledLayer))
setViewpoint(mapView.getCurrentViewpoint(Viewpoint.Type.CENTER_AND_SCALE))
}
// control UI visibility
previewMapView.getChildAt(0).visibility = View.VISIBLE
show(closeButton, dimBackground, previewTextView, previewMapView)
exportVectorTilesButton.visibility = View.GONE
// required for some Android devices running older OS (combats Z-ordering bug in Android API)
mapPreviewLayout.bringToFront()
}
/**
* Makes the given views in the UI visible.
* @param views the views to be made visible
*/
private fun show(vararg views: View) {
for (view in views) {
view.visibility = View.VISIBLE
}
}
/**
* Makes the given views in the UI visible.
* @param views the views to be made visible
*/
private fun hide(vararg views: View) {
for (view in views) {
view.visibility = View.INVISIBLE
}
}
/**
* Called when close preview MapView is clicked
*/
fun clearPreview(view: View) {
// control UI visibility
hide(closeButton, dimBackground, previewTextView, previewMapView)
show(exportVectorTilesButton, mapView)
downloadArea?.isVisible = true
// required for some Android devices running older OS (combats Z-ordering bug in Android API)
mapView.bringToFront()
}
private fun showError(message: String) {
Log.e(TAG, message)
Toast.makeText(this, message, Toast.LENGTH_SHORT).show()
}
override fun onPause() {
mapView.pause()
super.onPause()
}
override fun onResume() {
super.onResume()
mapView.resume()
}
override fun onDestroy() {
mapView.dispose()
super.onDestroy()
}
}