Retrieve elevation data
Note
This example is a part of the Mapbox Android Demo app. You can find the values for all referenced resources in the res directory. For example, see res/values/activity_strings.xml for R.string.* references used in this example.
Tilequery API pricing
Products used within the Mapbox Java SDK, including the Tilequery API, are individually billed. For pricing information, see the documentation for the Tilequery API.
activity_javaservices_elevation_query
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:mapbox="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/constraint_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".examples.javaservices.TilequeryActivity">
<com.mapbox.mapboxsdk.maps.MapView
android:id="@+id/mapView"
android:layout_width="0dp"
android:layout_height="0dp"
mapbox:layout_constraintBottom_toBottomOf="parent"
mapbox:layout_constraintEnd_toEndOf="parent"
mapbox:layout_constraintStart_toStartOf="parent"
mapbox:layout_constraintTop_toTopOf="parent"
mapbox:mapbox_cameraTargetLat="40.73581"
mapbox:mapbox_cameraTargetLng="-73.99155"
mapbox:mapbox_cameraZoom="11" />
<androidx.cardview.widget.CardView
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="28dp"
mapbox:layout_constraintBottom_toBottomOf="@+id/mapView"
mapbox:layout_constraintEnd_toEndOf="parent"
mapbox:layout_constraintStart_toStartOf="parent"
mapbox:layout_constraintTop_toTopOf="@+id/guideline8">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="@+id/textView7"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/elevation_api_response_textview"
android:textColor="@color/black_semi_transparent"
android:textStyle="bold" />
<TextView
android:id="@+id/textView8"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/elevation_api_response_ten_meter_textview"
android:textColor="@color/black_semi_transparent"
android:textSize="12sp" />
<TextView
android:id="@+id/elevation_query_api_response_elevation_numbers_only"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="@color/mapboxRedDark"
android:textSize="12sp"
tools:text="4 Features in the API response: 20, 30, 80, 90" />
<ScrollView
android:id="@+id/scrollView3"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/elevation_query_api_response_json_textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</ScrollView>
</LinearLayout>
</androidx.cardview.widget.CardView>
<androidx.constraintlayout.widget.Guideline
android:id="@+id/guideline8"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
mapbox:layout_constraintGuide_percent="0.7" />
</androidx.constraintlayout.widget.ConstraintLayout>
ElevationQueryActivity.java
package com.mapbox.mapboxandroiddemo.examples.javaservices;
import android.graphics.Color;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
import com.mapbox.android.core.permissions.PermissionsListener;
import com.mapbox.android.core.permissions.PermissionsManager;
import com.mapbox.api.tilequery.MapboxTilequery;
import com.mapbox.geojson.Feature;
import com.mapbox.geojson.FeatureCollection;
import com.mapbox.geojson.Point;
import com.mapbox.mapboxandroiddemo.R;
import com.mapbox.mapboxsdk.Mapbox;
import com.mapbox.mapboxsdk.camera.CameraPosition;
import com.mapbox.mapboxsdk.camera.CameraUpdateFactory;
import com.mapbox.mapboxsdk.geometry.LatLng;
import com.mapbox.mapboxsdk.location.LocationComponent;
import com.mapbox.mapboxsdk.location.LocationComponentActivationOptions;
import com.mapbox.mapboxsdk.location.modes.CameraMode;
import com.mapbox.mapboxsdk.location.modes.RenderMode;
import com.mapbox.mapboxsdk.maps.MapView;
import com.mapbox.mapboxsdk.maps.MapboxMap;
import com.mapbox.mapboxsdk.maps.OnMapReadyCallback;
import com.mapbox.mapboxsdk.maps.Style;
import com.mapbox.mapboxsdk.style.layers.SymbolLayer;
import com.mapbox.mapboxsdk.style.sources.GeoJsonSource;
import java.util.List;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import timber.log.Timber;
import static com.mapbox.mapboxsdk.style.expressions.Expression.get;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textAllowOverlap;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textColor;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textField;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textHaloBlur;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textIgnorePlacement;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textSize;
/**
* Use the Mapbox Tilequery API to access global elevation data. More info about
* elevation data can be found at
* https://docs.mapbox.com/help/troubleshooting/access-elevation-data/
*/
public class ElevationQueryActivity extends AppCompatActivity implements
OnMapReadyCallback, PermissionsListener, MapboxMap.OnMapClickListener {
private static final String RESULT_GEOJSON_SOURCE_ID = "RESULT_GEOJSON_SOURCE_ID";
private static final String LAYER_ID = "LAYER_ID";
private PermissionsManager permissionsManager;
private MapboxMap mapboxMap;
private MapView mapView;
private TextView elevationQueryNumbersOnlyResponseTextView;
private TextView elevationQueryJsonResponseTextView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Mapbox access token is configured here. This needs to be called either in your application
// object or in the same activity which contains the mapview.
Mapbox.getInstance(this, getString(R.string.access_token));
// This contains the MapView in XML and needs to be called after the access token is configured.
setContentView(R.layout.activity_javaservices_elevation_query);
elevationQueryJsonResponseTextView = findViewById(R.id.elevation_query_api_response_json_textview);
elevationQueryNumbersOnlyResponseTextView = findViewById(R.id.elevation_query_api_response_elevation_numbers_only);
mapView = findViewById(R.id.mapView);
mapView.onCreate(savedInstanceState);
mapView.getMapAsync(this);
}
@SuppressWarnings( {"MissingPermission"})
@Override
public void onMapReady(@NonNull final MapboxMap mapboxMap) {
ElevationQueryActivity.this.mapboxMap = mapboxMap;
mapboxMap.setStyle(Style.OUTDOORS, new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull Style style) {
addResultLayer(style);
displayDeviceLocation(style);
mapboxMap.addOnMapClickListener(ElevationQueryActivity.this);
Toast.makeText(ElevationQueryActivity.this, R.string.click_on_map_instruction, Toast.LENGTH_SHORT).show();
}
});
}
/**
* Add a map layer which will show a text number of the highest or lowest elevation number returned
* by the Tilequery API.
*/
private void addResultLayer(@NonNull Style loadedMapStyle) {
loadedMapStyle.addSource(new GeoJsonSource(RESULT_GEOJSON_SOURCE_ID));
loadedMapStyle.addLayer(new SymbolLayer(LAYER_ID, RESULT_GEOJSON_SOURCE_ID).withProperties(
textField(get("ele")),
textColor(Color.BLUE),
textSize(23f),
textHaloBlur(10f),
textIgnorePlacement(true),
textAllowOverlap(true)
));
}
@Override
public boolean onMapClick(@NonNull LatLng point) {
mapboxMap.getStyle(new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull Style style) {
// Use the map click location to make a request to the Tilequery API for elevation data.
makeElevationRequestToTilequeryApi(style, point);
}
});
return true;
}
/**
* Use the Java SDK's MapboxTilequery class to build a API request and use the API response
*
* @param point where the Tilequery API should query Mapbox's "mapbox.mapbox-terrain-v2" tileset
* for elevation data.
*/
private void makeElevationRequestToTilequeryApi(@NonNull final Style style, @NonNull LatLng point) {
MapboxTilequery elevationQuery = MapboxTilequery.builder()
.accessToken(getString(R.string.access_token))
.tilesetIds("mapbox.mapbox-terrain-v2")
.query(Point.fromLngLat(point.getLongitude(), point.getLatitude()))
.geometry("polygon")
.layers("contour")
.build();
elevationQuery.enqueueCall(new Callback<FeatureCollection>() {
@Override
public void onResponse(Call<FeatureCollection> call, Response<FeatureCollection> response) {
if (response.body().features() != null) {
List<Feature> featureList = response.body().features();
String listOfElevationNumbers = "";
// Build a list of the elevation numbers in the response.
for (Feature singleFeature : featureList) {
listOfElevationNumbers = listOfElevationNumbers + singleFeature.getStringProperty("ele") + ", ";
}
// Set this TextViews with the response info/JSON.
elevationQueryNumbersOnlyResponseTextView.setText(String.format(getString(
R.string.elevation_numbers_only_textview), featureList.size(), listOfElevationNumbers));
elevationQueryJsonResponseTextView.setText(response.body().toJson());
// Update the SymbolLayer that's responsible for showing the number text with the highest/lowest
// elevation number
if (featureList.size() > 0) {
GeoJsonSource resultSource = style.getSourceAs(RESULT_GEOJSON_SOURCE_ID);
if (resultSource != null) {
resultSource.setGeoJson(featureList.get(featureList.size() - 1));
}
}
} else {
String noFeaturesString = getString(R.string.elevation_tilequery_no_features);
Timber.d(noFeaturesString);
Toast.makeText(ElevationQueryActivity.this, noFeaturesString, Toast.LENGTH_SHORT).show();
elevationQueryNumbersOnlyResponseTextView.setText(noFeaturesString);
elevationQueryJsonResponseTextView.setText(noFeaturesString);
}
}
@Override
public void onFailure(Call<FeatureCollection> call, Throwable throwable) {
Timber.d("Request failed: %s", throwable.getMessage());
Toast.makeText(ElevationQueryActivity.this,
R.string.elevation_tilequery_api_response_error, Toast.LENGTH_SHORT).show();
}
});
}
/**
* Use the Maps SDK's LocationComponent to display the device location on the map
*/
@SuppressWarnings( {"MissingPermission"})
private void displayDeviceLocation(@NonNull Style loadedMapStyle) {
// Check if permissions are enabled and if not request
if (PermissionsManager.areLocationPermissionsGranted(this)) {
// Get an instance of the component
LocationComponent locationComponent = mapboxMap.getLocationComponent();
// Activate with options
locationComponent.activateLocationComponent(
LocationComponentActivationOptions.builder(this, loadedMapStyle).build());
// Enable to make component visible
locationComponent.setLocationComponentEnabled(true);
// Set the component's camera mode
locationComponent.setCameraMode(CameraMode.TRACKING);
locationComponent.setRenderMode(RenderMode.COMPASS);
// Zoom the camera into the device's current location
mapboxMap.animateCamera(CameraUpdateFactory
.newCameraPosition(new CameraPosition.Builder()
.zoom(10)
.build()), 2000);
} else {
permissionsManager = new PermissionsManager(this);
permissionsManager.requestLocationPermissions(this);
}
}
// The following three methods are related to showing the device's location via the LocationComponent
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
permissionsManager.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
@Override
public void onExplanationNeeded(List<String> permissionsToExplain) {
Toast.makeText(this, R.string.user_location_permission_explanation, Toast.LENGTH_LONG).show();
}
@Override
public void onPermissionResult(boolean granted) {
mapboxMap.getStyle(new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull Style style) {
if (granted) {
displayDeviceLocation(style);
} else {
Toast.makeText(ElevationQueryActivity.this,
R.string.user_location_permission_not_granted, Toast.LENGTH_LONG).show();
finish();
}
}
});
}
// Add the mapView lifecycle to the activity's lifecycle methods
@Override
public void onResume() {
super.onResume();
mapView.onResume();
}
@Override
protected void onStart() {
super.onStart();
mapView.onStart();
}
@Override
protected void onStop() {
super.onStop();
mapView.onStop();
}
@Override
public void onPause() {
super.onPause();
mapView.onPause();
}
@Override
public void onLowMemory() {
super.onLowMemory();
mapView.onLowMemory();
}
@Override
protected void onDestroy() {
super.onDestroy();
if (mapboxMap != null) {
mapboxMap.removeOnMapClickListener(this);
}
mapView.onDestroy();
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
mapView.onSaveInstanceState(outState);
}
}
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