Using Android device build-in light sensor in Android

It's a simple light meter Using Android device build-in light sensor. A ProgressBar is defined in main.xml as a indicator of the light sensor. The default value of 100 defined in android:max is a dummy value, it will be updated after lightSensor.getMaximumRange(). The updated reading will be be read in lightSensorEventListener, and update the ProgressBar accordingly.

package com.AndroidLightSensor;

 

import android.app.Activity;

import android.content.Context;

import android.hardware.Sensor;

import android.hardware.SensorEvent;

import android.hardware.SensorEventListener;

import android.hardware.SensorManager;

import android.os.Bundle;

import android.widget.ProgressBar;

import android.widget.TextView;

import android.widget.Toast;

 

public class AndroidLightSensorActivity extends Activity {

  

 ProgressBar lightMeter;

 TextView textMax, textReading;

  

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        lightMeter = (ProgressBar)findViewById(R.id.lightmeter);

        textMax = (TextView)findViewById(R.id.max);

        textReading = (TextView)findViewById(R.id.reading);

         

        SensorManager sensorManager

        = (SensorManager)getSystemService(Context.SENSOR_SERVICE);

        Sensor lightSensor

        = sensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);

      

        if (lightSensor == null){

         Toast.makeText(AndroidLightSensorActivity.this,

           "No Light Sensor! quit-",

           Toast.LENGTH_LONG).show();

        }else{

         float max =  lightSensor.getMaximumRange();

         lightMeter.setMax((int)max);

         textMax.setText("Max Reading: " + String.valueOf(max));

          

         sensorManager.registerListener(lightSensorEventListener,

           lightSensor,

           SensorManager.SENSOR_DELAY_NORMAL);

          

        }

    }

     

    SensorEventListener lightSensorEventListener

    = new SensorEventListener(){

 

  @Override

  public void onAccuracyChanged(Sensor sensor, int accuracy) {

   // TODO Auto-generated method stub

    

  }

 

  @Override

  public void onSensorChanged(SensorEvent event) {

   // TODO Auto-generated method stub

   if(event.sensor.getType()==Sensor.TYPE_LIGHT){

    float currentReading = event.values[0];

    lightMeter.setProgress((int)currentReading);

    textReading.setText("Current Reading: " + String.valueOf(currentReading));

   }

  }

      

    };

}