Examples

Update a choropleth layer by zoom level

activity_dds_choropleth_zoom_change
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".examples.dds.ChoroplethZoomChangeActivity">
<com.mapbox.mapboxsdk.maps.MapView
android:id="@+id/mapView"
android:layout_width="match_parent"
android:layout_height="match_parent"
mapbox:mapbox_cameraTargetLat="38.88"
mapbox:mapbox_cameraTargetLng="-98"
mapbox:mapbox_cameraZoom="3"
mapbox:mapbox_cameraZoomMin="3" />
</FrameLayout>
ChoroplethZoomChangeActivity
package com.mapbox.mapboxandroiddemo.examples.dds;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.appcompat.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.FillLayer;
import com.mapbox.mapboxsdk.style.layers.Layer;
import com.mapbox.mapboxsdk.style.sources.VectorSource;
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.rgb;
import static com.mapbox.mapboxsdk.style.expressions.Expression.step;
import static com.mapbox.mapboxsdk.style.expressions.Expression.stop;
import static com.mapbox.mapboxsdk.style.layers.Property.NONE;
import static com.mapbox.mapboxsdk.style.layers.Property.VISIBLE;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.fillColor;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.fillOpacity;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.visibility;
/**
* Display 2014 census data by state or county, depending on the map's zoom level.
*/
public class ChoroplethZoomChangeActivity extends AppCompatActivity {
private static final int ZOOM_THRESHOLD = 4;
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_dds_choropleth_zoom_change);
mapView = findViewById(R.id.mapView);
mapView.onCreate(savedInstanceState);
mapView.getMapAsync(new OnMapReadyCallback() {
@Override
public void onMapReady(@NonNull final MapboxMap mapboxMap) {
mapboxMap.setStyle(Style.LIGHT, new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull final Style style) {
VectorSource vectorSource = new VectorSource(
"population",
"http://api.mapbox.com/v4/mapbox.660ui7x6.json?access_token=" + Mapbox.getAccessToken()
);
style.addSource(vectorSource);
FillLayer statePopulationLayer = new FillLayer("state-population", "population");
statePopulationLayer.withSourceLayer("state_county_population_2014_cen");
statePopulationLayer.setFilter(Expression.eq(get("isState"), literal(true)));
statePopulationLayer.withProperties(
fillColor(step((get("population")), rgb(0,0,0),
stop(0, rgb(242,241,45)),
stop(750000, rgb(238,211,34)),
stop(1000000, rgb(218,156,32)),
stop(2500000, rgb(202,131,35)),
stop(5000000, rgb(184,107,37)),
stop(7500000, rgb(162,86,38)),
stop(10000000, rgb(139,66,37)),
stop(25000000, rgb(114,49,34)))),
fillOpacity(0.75f)
);
style.addLayerBelow(statePopulationLayer, "waterway-label");
FillLayer countyPopulationLayer = new FillLayer("county-population", "population");
countyPopulationLayer.withSourceLayer("state_county_population_2014_cen");
countyPopulationLayer.setFilter(Expression.eq(get("isCounty"), literal(true)));
countyPopulationLayer.withProperties(
fillColor(step(get("population"), rgb(0,0,0),
stop(0, rgb(242,241,45)),
stop(100, rgb(238,211,34)),
stop(1000, rgb(230,183,30)),
stop(5000, rgb(218,156,32)),
stop(10000, rgb(202,131,35)),
stop(50000, rgb(184,107,37)),
stop(100000, rgb(162,86,38)),
stop(500000, rgb(139,66,37)),
stop(1000000, rgb(114,49,34)))),
fillOpacity(0.75f),
visibility(NONE)
);
style.addLayerBelow(countyPopulationLayer, "waterway-label");
mapboxMap.addOnCameraMoveListener(new MapboxMap.OnCameraMoveListener() {
@Override
public void onCameraMove() {
Layer stateLayer = style.getLayer("state-population");
Layer countyLayer = style.getLayer("county-population");
if (mapboxMap.getCameraPosition().zoom > ZOOM_THRESHOLD) {
if (stateLayer != null && countyLayer != null) {
countyLayer.setProperties(visibility(VISIBLE));
}
} else {
if (stateLayer != null && countyLayer != null) {
countyLayer.setProperties(visibility(NONE));
}
}
}
});
}
});
}
});
}
@Override
protected void onStart() {
super.onStart();
mapView.onStart();
}
@Override
public void onResume() {
super.onResume();
mapView.onResume();
}
@Override
public void onPause() {
super.onPause();
mapView.onPause();
}
@Override
protected void onStop() {
super.onStop();
mapView.onStop();
}
@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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