Line gradient
A newer version of the Maps SDK is available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 A newer version of the SDK is available.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_line_gradient
<?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.LineGradientActivity">
<com.mapbox.mapboxsdk.maps.MapView
android:id="@+id/mapView"
android:layout_width="match_parent"
android:layout_height="match_parent"
mapbox:mapbox_cameraTargetLat="38.875"
mapbox:mapbox_cameraTargetLng="-77.035"
mapbox:mapbox_cameraZoom="12" />
</FrameLayout>
LineGradientActivity.java
package com.mapbox.mapboxandroiddemo.examples.dds;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import com.mapbox.geojson.Feature;
import com.mapbox.geojson.FeatureCollection;
import com.mapbox.geojson.LineString;
import com.mapbox.geojson.Point;
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.sources.GeoJsonOptions;
import com.mapbox.mapboxsdk.style.sources.GeoJsonSource;
import java.util.ArrayList;
import java.util.List;
import static com.mapbox.mapboxsdk.style.expressions.Expression.interpolate;
import static com.mapbox.mapboxsdk.style.expressions.Expression.lineProgress;
import static com.mapbox.mapboxsdk.style.expressions.Expression.linear;
import static com.mapbox.mapboxsdk.style.expressions.Expression.rgb;
import static com.mapbox.mapboxsdk.style.expressions.Expression.stop;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.lineCap;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.lineGradient;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.lineJoin;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.lineWidth;
/**
* Use data-driven styling properties to add color gradients to a LineLayer line.
*/
public class LineGradientActivity extends AppCompatActivity implements OnMapReadyCallback {
private MapView mapView;
private List<Point> routeCoordinates;
@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_line_gradient);
mapView = findViewById(R.id.mapView);
mapView.onCreate(savedInstanceState);
mapView.getMapAsync(this);
}
@Override
public void onMapReady(@NonNull final MapboxMap mapboxMap) {
mapboxMap.setStyle(Style.LIGHT, new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull Style style) {
initCoordinates();
// Create the LineString from the list of coordinates and then make a GeoJSON
// FeatureCollection so we can add the line to our map as a layer.
LineString lineString = LineString.fromLngLats(routeCoordinates);
FeatureCollection featureCollection = FeatureCollection.fromFeature(Feature.fromGeometry(lineString));
style.addSource(new GeoJsonSource("line-source", featureCollection,
new GeoJsonOptions().withLineMetrics(true)));
// The layer properties for our line. This is where we set the gradient colors, set the
// line width, etc
style.addLayer(new LineLayer("linelayer", "line-source").withProperties(
lineCap(Property.LINE_CAP_ROUND),
lineJoin(Property.LINE_JOIN_ROUND),
lineWidth(14f),
lineGradient(interpolate(
linear(), lineProgress(),
stop(0f, rgb(6, 1, 255)), // blue
stop(0.1f, rgb(59, 118, 227)), // royal blue
stop(0.3f, rgb(7, 238, 251)), // cyan
stop(0.5f, rgb(0, 255, 42)), // lime
stop(0.7f, rgb(255, 252, 0)), // yellow
stop(1f, rgb(255, 30, 0)) // red
))));
}
});
}
private void initCoordinates() {
routeCoordinates = new ArrayList<>();
routeCoordinates.add(Point.fromLngLat(-77.044211, 38.852924));
routeCoordinates.add(Point.fromLngLat(-77.045659, 38.860158));
routeCoordinates.add(Point.fromLngLat(-77.044232, 38.862326));
routeCoordinates.add(Point.fromLngLat(-77.040879, 38.865454));
routeCoordinates.add(Point.fromLngLat(-77.039936, 38.867698));
routeCoordinates.add(Point.fromLngLat(-77.040338, 38.86943));
routeCoordinates.add(Point.fromLngLat(-77.04264, 38.872528));
routeCoordinates.add(Point.fromLngLat(-77.03696, 38.878424));
routeCoordinates.add(Point.fromLngLat(-77.032309, 38.87937));
routeCoordinates.add(Point.fromLngLat(-77.030056, 38.880945));
routeCoordinates.add(Point.fromLngLat(-77.027645, 38.881779));
routeCoordinates.add(Point.fromLngLat(-77.026946, 38.882645));
routeCoordinates.add(Point.fromLngLat(-77.026942, 38.885502));
routeCoordinates.add(Point.fromLngLat(-77.028054, 38.887449));
routeCoordinates.add(Point.fromLngLat(-77.02806, 38.892088));
routeCoordinates.add(Point.fromLngLat(-77.03364, 38.892108));
routeCoordinates.add(Point.fromLngLat(-77.033643, 38.899926));
}
@Override
public void onStart() {
super.onStart();
mapView.onStart();
}
@Override
public void onResume() {
super.onResume();
mapView.onResume();
}
@Override
public void onPause() {
super.onPause();
mapView.onPause();
}
@Override
public 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);
}
}