Main Activity for the Barometer App on the SSaurel's Channel

MainActivity.java

package com.ssaurel.barometer;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

  private TextView txt;
  private SensorManager sensorManager;
  private Sensor pressureSensor;
  private SensorEventListener sensorEventListener = new SensorEventListener() {

    @Override
    public void onSensorChanged(SensorEvent sensorEvent) {
      float[] values = sensorEvent.values;
	  txt.setText(String.format("%.3f mbar", values[0]));
    }

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

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    txt = findViewById(R.id.txt);
    sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    pressureSensor = sensorManager.getDefaultSensor(Sensor.TYPE_PRESSURE);
  }

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

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