Proximity sensor

// Menifest
<uses-feature android:name="android.hardware.Sensor.proximity"
        android:required="true"/>
        
        //java
        
        
        public class MainActivity extends AppCompatActivity {

    Sensor proximitySensor;
    SensorEventListener sensorEventListener;
    SensorManager sensorManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sensorManager =(SensorManager) getSystemService(SENSOR_SERVICE);
        assert sensorManager != null;
        proximitySensor = sensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);
        if(proximitySensor==null){
            finish();
        }
        sensorEventListener = new SensorEventListener() {
            @Override
            public void onSensorChanged(SensorEvent sensorEvent) {
                if(sensorEvent.values[0]<proximitySensor.getMaximumRange()){
                getWindow().getDecorView().setBackgroundColor(Color.RED);
                }else{
                    getWindow().getDecorView().setBackgroundColor(Color.GREEN);
                }
            }

            @Override
            public void onAccuracyChanged(Sensor sensor, int i) {

            }
        }  ;
    }

    @Override
    protected void onResume() {
        super.onResume();
        sensorManager.registerListener(sensorEventListener,proximitySensor,SensorManager.SENSOR_DELAY_NORMAL);
    }

    @Override
    protected void onPause() {
        sensorManager.unregisterListener(sensorEventListener);
        super.onPause();

    }
}