How to set text on LineString in Mapbox SDK?

Question

I am working with the LineLayer from Mapbox SDK and having problems with getting text to show up on the line. There is an example from Mapbox.

This is what I have so far:

// Create a list to store our line coordinates.
routeCoordinates = new ArrayList<>();
routeCoordinates.add(Point.fromLngLat(-95.9928, 36.1540));
routeCoordinates.add(Point.fromLngLat(-95.9870, 36.1397));

// 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.fromFeatures(new com.mapbox.geojson.Feature[] {com.mapbox.geojson.Feature.fromGeometry(lineString)});
Source geoJsonSource = new GeoJsonSource("line-source", featureCollection);
mapbox.addSource(geoJsonSource);

LineLayer lineLayer = new LineLayer("linelayer", "line-source");
// The layer properties for our line. This is where we make the line dotted, set the
// color, etc.
lineLayer.setProperties(
     PropertyFactory.lineCap(Property.LINE_CAP_ROUND),
     PropertyFactory.lineJoin(Property.LINE_JOIN_ROUND),
     PropertyFactory.lineWidth(5f),
     PropertyFactory.lineColor(Color.parseColor("#e55e5e")),
     PropertyFactory.textField("some text"),
     PropertyFactory.textColor(Color.parseColor("#ffffff"))
);
mapbox.addLayer(lineLayer);

It won't add the string to the line as shown below.

Answer 1

The LineLayer class is based on the line layer in Mapbox GL JS. You can see available properties of this type of layer here , in the style spec documentation. As you can see, textField and textColor are not available properties.

One way to accomplish this would be to create an additional layer - this time of type SymbolLayer ( https://docs.mapbox.com/android/api/map-sdk/7.0.0/com/mapbox/mapboxsdk/style/layers/SymbolLayer.html ). This layer would have the same line data from your GeoJsonSource. You can read more about symbol layers here , but you can set text for this layer, and then set the symbol-placement property to line or line-center so the text aligns properly.