Android Sensor Example

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

   <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="Shake to switch color" />
   
</RelativeLayout>

package com.example.sensor;

import android.app.Activity;
import android.graphics.Color;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity implements SensorEventListener{
	private SensorManager sensorManager;
	  private boolean isColor = false;
	  private View view;
	  private long lastUpdate;

	  @Override
	  public void onCreate(Bundle savedInstanceState) {
	    super.onCreate(savedInstanceState);
	    setContentView(R.layout.activity_main);
	    view = findViewById(R.id.textView);
	    view.setBackgroundColor(Color.GREEN);

	    sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
	    lastUpdate = System.currentTimeMillis();
	  }
	  //overriding two methods of SensorEventListener
	  @Override
	  public void onAccuracyChanged(Sensor sensor, int accuracy) {}
	  @Override
	  public void onSensorChanged(SensorEvent event) {
	    if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
	      getAccelerometer(event);
	    }

	  }

	  private void getAccelerometer(SensorEvent event) {
	    float[] values = event.values;
	    // Movement
	    float x = values[0];
	    float y = values[1];
	    float z = values[2];

	    float accelationSquareRoot = (x * x + y * y + z * z)
	        / (SensorManager.GRAVITY_EARTH * SensorManager.GRAVITY_EARTH);
	    
	    long actualTime = System.currentTimeMillis();
	    Toast.makeText(getApplicationContext(),String.valueOf(accelationSquareRoot)+" "+
                    SensorManager.GRAVITY_EARTH,Toast.LENGTH_SHORT).show();
	    
	    if (accelationSquareRoot >= 2) //it will be executed if you shuffle
	    {
	      
	      if (actualTime - lastUpdate < 200) {
	        return;
	      }
	      lastUpdate = actualTime;//updating lastUpdate for next shuffle
	       if (isColor) {
	        view.setBackgroundColor(Color.GREEN);

	      } else {
	        view.setBackgroundColor(Color.RED);
	      }
	      isColor = !isColor;
	    }
	  }

	  @Override
	  protected void onResume() {
	    super.onResume();
	    // register this class as a listener for the orientation and
	    // accelerometer sensors
	    sensorManager.registerListener(this,sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
                                    SensorManager.SENSOR_DELAY_NORMAL);
	  }

	  @Override
	  protected void onPause() {
	    // unregister listener
	    super.onPause();
	    sensorManager.unregisterListener(this);
	  }
	}