Examples
Dynamic styling (32)

Draw a GeoJSON line

package com.mapbox.mapboxandroiddemo.examples.dds;
import android.graphics.Color;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import com.mapbox.geojson.FeatureCollection;
import com.mapbox.mapboxandroiddemo.R;
import com.mapbox.mapboxsdk.Mapbox;
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.LineLayer;
import com.mapbox.mapboxsdk.style.layers.Property;
import com.mapbox.mapboxsdk.style.layers.PropertyFactory;
import com.mapbox.mapboxsdk.style.sources.GeoJsonSource;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.util.Scanner;
import timber.log.Timber;
/**
* Draw a polyline by parsing a GeoJSON file with the Mapbox Android SDK.
*/
public class DrawGeojsonLineActivity extends AppCompatActivity implements OnMapReadyCallback {
private MapView mapView;
private MapboxMap mapboxMap;
@Override
public 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_annotation_geojson_line);
mapView = findViewById(R.id.mapView);
mapView.onCreate(savedInstanceState);
mapView.getMapAsync(this);
}
@Override
public void onMapReady(@NonNull MapboxMap mapboxMap) {
this.mapboxMap = mapboxMap;
mapboxMap.setStyle(Style.MAPBOX_STREETS, new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull Style style) {
new LoadGeoJson(DrawGeojsonLineActivity.this).execute();
}
});
}
private void drawLines(@NonNull FeatureCollection featureCollection) {
if (mapboxMap != null) {
mapboxMap.getStyle(style -> {
if (featureCollection.features().size() > 0) {
style.addSource(new GeoJsonSource("line-source", featureCollection));
// The layer properties for our line. This is where we make the line dotted, set the
// color, etc.
style.addLayer(new LineLayer("linelayer", "line-source")
.withProperties(PropertyFactory.lineCap(Property.LINE_CAP_SQUARE),
PropertyFactory.lineJoin(Property.LINE_JOIN_MITER),
PropertyFactory.lineOpacity(.7f),
PropertyFactory.lineWidth(7f),
PropertyFactory.lineColor(Color.parseColor("#3bb2d0"))));
}
});
}
}
private static class LoadGeoJson extends AsyncTask<Void, Void, FeatureCollection> {
private WeakReference<DrawGeojsonLineActivity> weakReference;
LoadGeoJson(DrawGeojsonLineActivity activity) {
this.weakReference = new WeakReference<>(activity);
}
@Override
protected FeatureCollection doInBackground(Void... voids) {
try {
DrawGeojsonLineActivity activity = weakReference.get();
if (activity != null) {
InputStream inputStream = activity.getAssets().open("example.geojson");
return FeatureCollection.fromJson(convertStreamToString(inputStream));
}
} catch (Exception exception) {
Timber.e("Exception Loading GeoJSON: %s" , exception.toString());
}
return null;
}
static String convertStreamToString(InputStream is) {
Scanner scanner = new Scanner(is).useDelimiter("\\A");
return scanner.hasNext() ? scanner.next() : "";
}
@Override
protected void onPostExecute(@Nullable FeatureCollection featureCollection) {
super.onPostExecute(featureCollection);
DrawGeojsonLineActivity activity = weakReference.get();
if (activity != null && featureCollection != null) {
activity.drawLines(featureCollection);
}
}
}
@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 onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
mapView.onSaveInstanceState(outState);
}
@Override
public void onLowMemory() {
super.onLowMemory();
mapView.onLowMemory();
}
@Override
public void onDestroy() {
super.onDestroy();
mapView.onDestroy();
}
}
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