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Variable label placement

A newer version of the Maps SDK is available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 A newer version of the SDK is available.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, v11.2.2, 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_variable_text_placement
<?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"
android:layout_width="match_parent"
android:layout_height="match_parent">

<com.mapbox.mapboxsdk.maps.MapView
android:id="@+id/mapView"
android:layout_width="match_parent"
android:layout_height="match_parent"
mapbox:mapbox_cameraTargetLat="38.907"
mapbox:mapbox_cameraTargetLng="-77.04"
mapbox:mapbox_cameraZoom="11.15"/>

</FrameLayout>
VariableLabelPlacementActivity.java
package com.mapbox.mapboxandroiddemo.examples.styles;

import android.graphics.Color;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import timber.log.Timber;

import android.widget.Toast;

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.SymbolLayer;
import com.mapbox.mapboxsdk.style.sources.GeoJsonSource;

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

import static com.mapbox.mapboxsdk.style.expressions.Expression.get;
import static com.mapbox.mapboxsdk.style.layers.Property.TEXT_ANCHOR_BOTTOM;
import static com.mapbox.mapboxsdk.style.layers.Property.TEXT_ANCHOR_LEFT;
import static com.mapbox.mapboxsdk.style.layers.Property.TEXT_ANCHOR_RIGHT;
import static com.mapbox.mapboxsdk.style.layers.Property.TEXT_ANCHOR_TOP;
import static com.mapbox.mapboxsdk.style.layers.Property.TEXT_JUSTIFY_AUTO;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textColor;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textField;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textJustify;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textRadialOffset;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textSize;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.textVariableAnchor;


/**
* To increase the chance of high-priority labels staying visible, provide the map
* renderer a list of preferred text anchor positions via
* {@link com.mapbox.mapboxsdk.style.layers.PropertyFactory#textVariableAnchor(String[])}.
*/
public class VariableLabelPlacementActivity extends AppCompatActivity {

private static final String GEOJSON_SRC_ID = "poi_source_id";
private static final String POI_LABELS_LAYER_ID = "poi_labels_layer_id";
private MapView mapView;
private GeoJsonSource geoJsonSource;

@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_variable_text_placement);

mapView = findViewById(R.id.mapView);
mapView.onCreate(savedInstanceState);
mapView.getMapAsync(new OnMapReadyCallback() {
@Override
public void onMapReady(@NonNull final MapboxMap mapboxMap) {
try {
geoJsonSource = new GeoJsonSource(GEOJSON_SRC_ID, new URI("asset://poi_places.geojson"));

mapboxMap.setStyle(new Style.Builder().fromUri(Style.LIGHT)
.withSource(geoJsonSource)
// Adds a SymbolLayer to display POI labels
.withLayer(new SymbolLayer(POI_LABELS_LAYER_ID, GEOJSON_SRC_ID)
.withProperties(
textField(get("description")),
textSize(17f),
textColor(Color.RED),
textVariableAnchor(
new String[]{TEXT_ANCHOR_TOP, TEXT_ANCHOR_BOTTOM, TEXT_ANCHOR_LEFT, TEXT_ANCHOR_RIGHT}),
textJustify(TEXT_JUSTIFY_AUTO),
textRadialOffset(0.5f))),
new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull final Style style) {
Toast.makeText(VariableLabelPlacementActivity.this,
getString(R.string.zoom_map_in_and_out_variable_label_instruction),
Toast.LENGTH_SHORT).show();
}
});
} catch (URISyntaxException exception) {
Timber.d(exception);
}
}
});
}

// Add the mapView lifecycle to the activity's lifecycle methods
@Override
public void onResume() {
super.onResume();
mapView.onResume();
}

@Override
protected void onStart() {
super.onStart();
mapView.onStart();
}

@Override
protected void onStop() {
super.onStop();
mapView.onStop();
}

@Override
public void onPause() {
super.onPause();
mapView.onPause();
}

@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);
}
}