Icon update based on API response
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This page uses v9.7.1 of the Mapbox Maps SDK. A newer version of the SDK is available. Learn about the latest version, v11.3.0, in the Maps SDK documentation.
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.
activity_lab_space_station_location
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".examples.labs.SpaceStationLocationActivity">
<com.mapbox.mapboxsdk.maps.MapView
android:id="@+id/mapView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</FrameLayout>
SpaceStationLocationActivity.java
package com.mapbox.mapboxandroiddemo.examples.labs;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.widget.Toast;
import com.mapbox.geojson.Feature;
import com.mapbox.geojson.FeatureCollection;
import com.mapbox.geojson.Point;
import com.mapbox.mapboxandroiddemo.R;
import com.mapbox.mapboxandroiddemo.model.IssModel;
import com.mapbox.mapboxsdk.Mapbox;
import com.mapbox.mapboxsdk.camera.CameraUpdateFactory;
import com.mapbox.mapboxsdk.geometry.LatLng;
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 androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
import retrofit2.http.GET;
import timber.log.Timber;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.iconAllowOverlap;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.iconIgnorePlacement;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.iconImage;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.iconSize;
/**
* Display the space station's real-time location
*/
public class SpaceStationLocationActivity extends AppCompatActivity {
private static final String TAG = "SpaceStationActivity";
private Handler handler;
private Runnable runnable;
private Call<IssModel> call;
// apiCallTime is the time interval when we call the API in milliseconds, by default this is set
// to 2000 and you should only increase the value, reducing the interval will only cause server
// traffic, the latitude and longitude values aren't updated that frequently.
private int apiCallTime = 2000;
// Map variables
private MapView mapView;
private MapboxMap map;
@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_lab_space_station_location);
// Initialize the MapView
mapView = findViewById(R.id.mapView);
mapView.onCreate(savedInstanceState);
mapView.getMapAsync(new OnMapReadyCallback() {
@Override
public void onMapReady(@NonNull final MapboxMap mapboxMap) {
map = mapboxMap;
mapboxMap.setStyle(Style.SATELLITE_STREETS, new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull Style style) {
initSpaceStationSymbolLayer(style);
callApi();
Toast.makeText(SpaceStationLocationActivity.this, R.string.space_station_toast, Toast.LENGTH_SHORT).show();
}
});
}
});
}
private void callApi() {
// Build our client, The API we are using is very basic only returning a handful of
// information, mainly, the current latitude and longitude of the International Space Station.
Retrofit client = new Retrofit.Builder()
.baseUrl("http://api.open-notify.org/")
.addConverterFactory(GsonConverterFactory.create())
.build();
final IssApiService service = client.create(IssApiService.class);
// A handler is needed to called the API every x amount of seconds.
handler = new Handler();
runnable = new Runnable() {
@Override
public void run() {
// Call the API so we can get the updated coordinates.
call = service.loadLocation();
call.enqueue(new Callback<IssModel>() {
@Override
public void onResponse(Call<IssModel> call, Response<IssModel> response) {
// We only need the latitude and longitude from the API.
if (response.body() != null) {
double latitude = response.body().getIssPosition().getLatitude();
double longitude = response.body().getIssPosition().getLongitude();
updateMarkerPosition(new LatLng(latitude, longitude));
}
}
@Override
public void onFailure(Call<IssModel> call, Throwable throwable) {
// If retrofit fails or the API was unreachable, an error will be called.
//to check if throwable is null, then give a custom message.
if (throwable.getMessage() == null) {
Timber.e("Http connection failed");
} else {
Timber.e(throwable.getMessage());
}
}
});
// Schedule the next execution time for this runnable.
handler.postDelayed(this, apiCallTime);
}
};
// The first time this runs we don't need a delay so we immediately post.
handler.post(runnable);
}
private void initSpaceStationSymbolLayer(@NonNull Style style) {
style.addImage("space-station-icon-id",
BitmapFactory.decodeResource(
this.getResources(), R.drawable.iss));
style.addSource(new GeoJsonSource("source-id"));
style.addLayer(new SymbolLayer("layer-id", "source-id").withProperties(
iconImage("space-station-icon-id"),
iconIgnorePlacement(true),
iconAllowOverlap(true),
iconSize(.7f)
));
}
private void updateMarkerPosition(LatLng position) {
// This method is where we update the marker position once we have new coordinates. First we
// check if this is the first time we are executing this handler, the best way to do this is
// check if marker is null;
if (map.getStyle() != null) {
GeoJsonSource spaceStationSource = map.getStyle().getSourceAs("source-id");
if (spaceStationSource != null) {
spaceStationSource.setGeoJson(FeatureCollection.fromFeature(
Feature.fromGeometry(Point.fromLngLat(position.getLongitude(), position.getLatitude()))
));
}
}
// Lastly, animate the camera to the new position so the user
// wont have to search for the marker and then return.
map.animateCamera(CameraUpdateFactory.newLatLng(position));
}
// Interface used for Retrofit.
public interface IssApiService {
@GET("iss-now")
Call<IssModel> loadLocation();
}
@Override
public void onResume() {
super.onResume();
mapView.onResume();
// When the user returns to the activity we want to resume the API calling.
if (handler != null && runnable != null) {
handler.post(runnable);
}
}
@Override
protected void onStart() {
super.onStart();
mapView.onStart();
}
@Override
protected void onStop() {
super.onStop();
mapView.onStop();
}
@Override
public void onPause() {
super.onPause();
mapView.onPause();
// When the user leaves the activity, there is no need in calling the API since the map
// isn't in view.
if (handler != null && runnable != null) {
handler.removeCallbacks(runnable);
}
}
@Override
public void onLowMemory() {
super.onLowMemory();
mapView.onLowMemory();
}
@Override
protected void onDestroy() {
super.onDestroy();
mapView.onDestroy();
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
mapView.onSaveInstanceState(outState);
}
}