Deepak Nenmini

deepak - Wed Mar 28 2012 23:36:30 GMT-0400 (EDT)

SENSOR is the key word here

SENSOR is the key word here

deepak - Wed Mar 28 2012 23:37:06 GMT-0400 (EDT)

SensorEventListener API reference

SensorEventListener API reference

deepak - Wed Mar 28 2012 23:40:20 GMT-0400 (EDT)

SensorEventListener

When sensor values changes, Sensor manager 
calls the sensor event listener for notifications.

Two methods needs to be implemented as part of this Interface


public abstract void onAccuracyChanged (Sensor sensor, int accuracy);

public abstract void onSensorChanged (SensorEvent event);

deepak - Wed Mar 28 2012 23:43:48 GMT-0400 (EDT)

Here is the sample program Step 1

 Use the below class as the Implementation for the sensor event listener interface 

package com.ai.app.game.unscramble.expert.listener;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;


/**
 * Listener that detects shake gesture.
 */
public class ShakeEventListener implements SensorEventListener {


  /** Minimum movement force to consider. */
  private static final int MIN_FORCE = 10;

  /**
   * Minimum times in a shake gesture that the 
direction of movement needs to
   * change.
   */
  private static final int MIN_DIRECTION_CHANGE = 3;

  /** Maximum pause between movements. */
  private static final int MAX_PAUSE_BETHWEEN_DIRECTION_CHANGE = 200;

  /** Maximum allowed time for shake gesture. */
  private static final int MAX_TOTAL_DURATION_OF_SHAKE = 400;

  /** Time when the gesture started. */
  private long mFirstDirectionChangeTime = 0;

  /** Time when the last movement started. */
  private long mLastDirectionChangeTime;

  /** How many movements are considered so far. */
  private int mDirectionChangeCount = 0;

  /** The last x position. */
  private float lastX = 0;

  /** The last y position. */
  private float lastY = 0;

  /** The last z position. */
  private float lastZ = 0;

  /** OnShakeListener that is called 
when shake is detected. */
  private OnShakeListener mShakeListener;

  /**
   * Interface for shake gesture.
   */
  public interface OnShakeListener {

    /**
     * Called when shake gesture is detected.
     */
    void onShake();
  }

  public void 
setOnShakeListener(OnShakeListener listener) {
    mShakeListener = listener;
  }

  @Override
  public void onSensorChanged(SensorEvent se) {
    // get sensor data
    float x = se.values[SensorManager.DATA_X];
    float y = se.values[SensorManager.DATA_Y];
    float z = se.values[SensorManager.DATA_Z];

    // calculate movement
    float totalMovement = 
Math.abs(x + y + z - lastX - lastY - lastZ);

    if (totalMovement > MIN_FORCE) {

      // get time
      long now = System.currentTimeMillis();

      // store first movement time
      if (mFirstDirectionChangeTime == 0) {
        mFirstDirectionChangeTime = now;
        mLastDirectionChangeTime = now;
      }

      // check if the last movement was not long ago
      long lastChangeWasAgo = now - mLastDirectionChangeTime;
      if (lastChangeWasAgo 
< MAX_PAUSE_BETHWEEN_DIRECTION_CHANGE) {

        // store movement data
        mLastDirectionChangeTime = now;
        mDirectionChangeCount++;

        // store last sensor data 
        lastX = x;
        lastY = y;
        lastZ = z;

        // check how many movements are so far
        if (mDirectionChangeCount >= 
MIN_DIRECTION_CHANGE) {

          // check total duration
          long totalDuration = now - mFirstDirectionChangeTime;
          if (totalDuration < 
MAX_TOTAL_DURATION_OF_SHAKE) {
            mShakeListener.onShake();
            resetShakeParameters();
          }
        }

      } else {
        resetShakeParameters();
      }
    }
  }

  /**
   * Resets the shake parameters to their default values.
   */
  private void resetShakeParameters() {
    mFirstDirectionChangeTime = 0;
    mDirectionChangeCount = 0;
    mLastDirectionChangeTime = 0;
    lastX = 0;
    lastY = 0;
    lastZ = 0;
  }

  @Override
  public void onAccuracyChanged(Sensor sensor, i
nt accuracy) {
  }

}

deepak - Wed Mar 28 2012 23:44:57 GMT-0400 (EDT)

Step 2 : Create Global variable in your activity

   /**
    * SensorManager handle
    */
   private SensorManager mSensorManager;

   /**
    * ShakeEventListener handle
    */
   private ShakeEventListener mSensorListener;

deepak - Wed Mar 28 2012 23:47:14 GMT-0400 (EDT)

Step 3: Initialize it in the onCreate() of your activity

 call the below method from the onCreate()

private void setUpShakeListener()
   {
      mSensorListener = new ShakeEventListener();
       mSensorManager = (SensorManager) 
getSystemService(Context.SENSOR_SERVICE);
       mSensorManager.registerListener(mSensorListener,
           mSensorManager.getDefaultSensor
(Sensor.TYPE_ACCELEROMETER),
           SensorManager.SENSOR_DELAY_UI);


       mSensorListener.setOnShakeListener(new 
ShakeEventListener.OnShakeListener() {

         public void onShake() {
            scrambleWord();
         }
       });
   }

deepak - Wed Mar 28 2012 23:48:56 GMT-0400 (EDT)

Step 4: Register and Unregister on onPause() and onResume()

protected void onPause() {
      // TODO Auto-generated method stub
      super.onPause();
      cancel();
      }
      
      mSensorManager.unregisterListener(mSensorListener);

   }
   
   
   @Override
     protected void onResume() {
       super.onResume();
       mSensorManager.registerListener(mSensorListener,
           mSensorManager.
getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
           SensorManager.SENSOR_DELAY_UI);
     }