# Update a choropleth layer by zoom level

> **Note (legacy): A newer version of the Maps SDK is available**
> 
> This page uses v9.7.1 of the Mapbox Maps SDK. A newer version of the SDK is available. Learn about the latest version, v11.31.0, in the [Maps SDK documentation](https://docs.mapbox.com/android/ja/maps/guides/).

Your browser doesn't support HTML5 video. Open [link to the video](https://docs.mapbox.com/android/ja/android/ja/assets/medias/maps-example-choropleth-zoom-change-activity-af319ffeb8c96e20979e1043d2ba9fe9.mp4).

> **Note**
> 
> This example is a part of the [Mapbox Android Demo app](https://github.com/mapbox/mapbox-android-demo). You can find the values for all referenced resources in the [`res`](https://github.com/mapbox/mapbox-android-demo/tree/master/MapboxAndroidDemo/src/main/res) directory. For example, see [`res/values/activity_strings.xml`](https://github.com/mapbox/mapbox-android-demo/tree/master/MapboxAndroidDemo/src/main/res/values/activity_strings.xml) for `R.string.*` references used in this example. The dependencies can be found [here.](https://github.com/mapbox/mapbox-navigation-android-examples/blob/main/app/build.gradle) The examples use View binding. [See setup documention if necessary.](https://developer.android.com/topic/libraries/view-binding)

Title: `activity_dds_choropleth_zoom_change`

[View on GitHub](https://github.com/mapbox/mapbox-android-demo/tree/master/MapboxAndroidDemo/src/main/res/layout/activity_dds_choropleth_zoom_change.xml)

```xml
<?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>
```

**Java**

Title: `ChoroplethZoomChangeActivity.java`

[View on GitHub](https://github.com/mapbox/mapbox-android-demo/tree/master/MapboxAndroidDemo/src/main/java/com/mapbox/mapboxandroiddemo/examples/dds/ChoroplethZoomChangeActivity.java)

```java
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);
  }
}
```