Examples
Dynamic styling (32)

Adjust a layer's opacity

package com.mapbox.mapboxandroiddemo.examples.styles;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.widget.SeekBar;
import android.widget.TextView;
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.Layer;
import com.mapbox.mapboxsdk.style.layers.RasterLayer;
import com.mapbox.mapboxsdk.style.sources.RasterSource;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.rasterOpacity;
/**
* Use a seekbar to adjust the opacity of a raster layer on top of a map.
*/
public class AdjustLayerOpacityActivity extends AppCompatActivity {
private MapView mapView;
private MapboxMap map;
private Layer chicago;
@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_adjust_layer_opacity);
final SeekBar opacitySeekBar = findViewById(R.id.seek_bar_layer_opacity);
final TextView percentTextView = findViewById(R.id.textview_opacity_value);
opacitySeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
if (chicago != null) {
chicago.setProperties(
rasterOpacity((float) progress / 100)
);
}
String progressPercentage = progress + "%";
percentTextView.setText(progressPercentage);
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
mapView = findViewById(R.id.mapView);
mapView.onCreate(savedInstanceState);
mapView.getMapAsync(new OnMapReadyCallback() {
@Override
public void onMapReady(@NonNull MapboxMap mapboxMap) {
map = mapboxMap;
mapboxMap.setStyle(Style.LIGHT, new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull Style style) {
style.addSource(new RasterSource("chicago-source", "mapbox://mapbox.u8yyzaor"));
style.addLayer(new RasterLayer("chicago", "chicago-source"));
chicago = map.getStyle().getLayer("chicago");
}
});
}
});
}
@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);
}
}