Examples
Dynamic styling (32)

Create hotspots from points

package com.mapbox.mapboxandroiddemo.examples.dds;
import android.graphics.Color;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
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.expressions.Expression;
import com.mapbox.mapboxsdk.style.layers.CircleLayer;
import com.mapbox.mapboxsdk.style.sources.GeoJsonOptions;
import com.mapbox.mapboxsdk.style.sources.GeoJsonSource;
import java.net.MalformedURLException;
import java.net.URL;
import timber.log.Timber;
import static com.mapbox.mapboxsdk.style.expressions.Expression.get;
import static com.mapbox.mapboxsdk.style.expressions.Expression.literal;
import static com.mapbox.mapboxsdk.style.expressions.Expression.toNumber;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.circleBlur;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.circleColor;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.circleRadius;
/**
* Use Mapbox GL clustering to visualize point data as hotspots.
*/
public class CreateHotspotsActivity extends AppCompatActivity {
private MapView mapView;
@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_style_create_hotspots_points);
mapView = findViewById(R.id.mapView);
mapView.onCreate(savedInstanceState);
mapView.getMapAsync(new OnMapReadyCallback() {
@Override
public void onMapReady(@NonNull final MapboxMap mapboxMap) {
mapboxMap.setStyle(Style.DARK, new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull Style style) {
addClusteredGeoJsonSource(style);
}
});
}
});
}
private void addClusteredGeoJsonSource(@NonNull Style loadedMapStyle) {
// Add a new source from our GeoJSON data and set the 'cluster' option to true.
try {
loadedMapStyle.addSource(
// Point to GeoJSON data. This example visualizes all M1.0+ earthquakes from
// 12/22/15 to 1/21/16 as logged by USGS' Earthquake hazards program.
new GeoJsonSource("earthquakes",
new URL("https://www.mapbox.com/mapbox-gl-js/assets/earthquakes.geojson"),
new GeoJsonOptions()
.withCluster(true)
.withClusterMaxZoom(15) // Max zoom to cluster points on
.withClusterRadius(20) // Use small cluster radius for the hotspots look
)
);
} catch (MalformedURLException malformedUrlException) {
Timber.e("Check the URL %s", malformedUrlException.getMessage());
}
// Use the earthquakes source to create four layers:
// three for each cluster category, and one for unclustered points
// Each point range gets a different fill color.
final int[][] layers = new int[][] {
new int[] {150, Color.parseColor("#E55E5E")},
new int[] {20, Color.parseColor("#F9886C")},
new int[] {0, Color.parseColor("#FBB03B")}
};
CircleLayer unclustered = new CircleLayer("unclustered-points", "earthquakes");
unclustered.setProperties(
circleColor(Color.parseColor("#FBB03B")),
circleRadius(20f),
circleBlur(1f));
unclustered.setFilter(Expression.neq(get("cluster"), literal(true)));
loadedMapStyle.addLayerBelow(unclustered, "building");
for (int i = 0; i < layers.length; i++) {
CircleLayer circles = new CircleLayer("cluster-" + i, "earthquakes");
circles.setProperties(
circleColor(layers[i][1]),
circleRadius(70f),
circleBlur(1f)
);
Expression pointCount = toNumber(get("point_count"));
circles.setFilter(
i == 0
? Expression.gte(pointCount, literal(layers[i][0])) :
Expression.all(
Expression.gte(pointCount, literal(layers[i][0])),
Expression.lt(pointCount, literal(layers[i - 1][0]))
)
);
loadedMapStyle.addLayerBelow(circles, "building");
}
}
@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();
mapView.onDestroy();
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
mapView.onSaveInstanceState(outState);
}
}
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