Style lines using an identity property function | Maps SDK v9 | Android Docs

A newer version of the Maps SDK is available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 A newer version of the SDK is available.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, v11.3.0, 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_style_line

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<?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="com.mapbox.mapboxandroiddemo.examples.dds.StyleLineIdentityPropertyActivity">

    <com.mapbox.mapboxsdk.maps.MapView
        android:id="@+id/mapView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        mapbox:mapbox_cameraTargetLat="37.82882682974591"
        mapbox:mapbox_cameraTargetLng="-122.48383155304096"
        mapbox:mapbox_cameraZoom="15.3"/>

</FrameLayout>

StyleLineIdentityPropertyActivity.java

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package com.mapbox.mapboxandroiddemo.examples.dds;

import android.os.Bundle;

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.net.URI;
import java.net.URISyntaxException;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import timber.log.Timber;

import static com.mapbox.mapboxsdk.style.expressions.Expression.get;
import static com.mapbox.mapboxsdk.style.expressions.Expression.match;
import static com.mapbox.mapboxsdk.style.expressions.Expression.rgb;
import static com.mapbox.mapboxsdk.style.expressions.Expression.stop;

/**
 * Use data-driven styling to set a line's color based on imported GeoJSON.
 */
public class StyleLineIdentityPropertyActivity 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_line);

    mapView = findViewById(R.id.mapView);
    mapView.onCreate(savedInstanceState);
    mapView.getMapAsync(new OnMapReadyCallback() {
      @Override
      public void onMapReady(@NonNull final MapboxMap mapboxMap) {

        mapboxMap.setStyle(Style.MAPBOX_STREETS, new Style.OnStyleLoaded() {
          @Override
          public void onStyleLoaded(@NonNull Style style) {
            try {
              // Retrieve GeoJSON from local file and add it to the map
              style.addSource(new GeoJsonSource("lines",
                new URI("asset://golden_gate_lines.geojson")));
            } catch (URISyntaxException exception) {
              Timber.d(exception);
            }

            // Create a LineLayer. Use lineColor and stops to draw red and blue lines on the map
            style.addLayer(new LineLayer("finalLines", "lines").withProperties(
              PropertyFactory.lineColor(
                match(get("color"), rgb(0, 0, 0),
                  stop("red", rgb(247, 69, 93)),
                  stop("blue", rgb(51, 201, 235)))),
              PropertyFactory.visibility(Property.VISIBLE),
              PropertyFactory.lineWidth(3f)
            ));
          }
        });
      }
    });
  }

  @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);
  }
}