How can I make android react as in a call and the proximity sensor is triggered?

Question

I have an application which makes VoIp call. During those call, I would like the screen to react exactly as it does during a normal call. That is, i want the screen to disable all events and turn off when the user triggers the proximity sensor. Of course, when the user moves away his ear from the phone, I want the phone to turn the screen on and enable back all events. I tried before to turn off and on the screen myself. Never worked. So I thought i'd used this solution.

Answer 1

There is a similar question I found which gives some great info on the Proximity Sensor using samples from the Android Phone app.

android: turn off screen when close to face

Answer 2

Here is the code which may help you ..this demonstrate how we can access proximity sensor using SensorManager Class,here the proximity sensor will triggered an it calls a method which changes an image view you can try your code on that method...., get the Whole Source code here

public class MainActivity extends Activity {
SensorManager sm;
Sensor ProximitySensor;
boolean state=true;
@Override
public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    txstate= (TextView) findViewById(R.id.txstate);
    sm = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
    ProximitySensor = sm.getDefaultSensor(Sensor.TYPE_PROXIMITY);
    sm.registerListener(proximitySensorEventListener,  ProximitySensor, SensorManager.SENSOR_DELAY_FASTEST);


}
SensorEventListener proximitySensorEventListener = new SensorEventListener()
{   
  @Override
  public void onAccuracyChanged(Sensor sensor, int accuracy) 
  {

  }
@Override
public void onSensorChanged(SensorEvent event) 
{
if(event.sensor.getType()==Sensor.TYPE_PROXIMITY)


    {if((int)(event.values[0])==1)

        {

                    call();
        }
    }

}

private void call() 

{
        ImageView im = (ImageView) findViewById(R.id.imageView1);
        if(state)
        {
            state =false;                
            im.setImageResource(R.drawable.smile);                   
        }
        else 
        {
            state=true;              
            im.setImageResource(R.drawable.sad);             
        }
    }
};
}