Android: How to handle right to left swipe gestures

Question

I want my app to recognize when a user swipes from right to left on the phone screen.

How to do this?

Answer 1

public class TranslatorSwipeTouch implements OnTouchListener
{
   private String TAG="TranslatorSwipeTouch";

   @SuppressWarnings("deprecation")
   private GestureDetector detector=new GestureDetector(new TranslatorGestureListener());

   @Override
   public boolean onTouch(View view, MotionEvent event)
   {
     return detector.onTouchEvent(event);
   }

private class TranslatorGestureListener extends SimpleOnGestureListener 
{
    private final int GESTURE_THRESHOULD=100;
    private final int GESTURE_VELOCITY_THRESHOULD=100;

    @Override
    public boolean onDown(MotionEvent e) {
        return true;
    }

    @Override
    public boolean onFling(MotionEvent event1,MotionEvent event2,float velocityx,float velocityy)
    {
        try
        {
            float diffx=event2.getX()-event1.getX();
            float diffy=event2.getY()-event1.getY();

            if(Math.abs(diffx)>Math.abs(diffy))
            {
                if(Math.abs(diffx)>GESTURE_THRESHOULD && Math.abs(velocityx)>GESTURE_VELOCITY_THRESHOULD)
                {
                    if(diffx>0)
                    {
                        onSwipeRight();
                    }
                    else
                    {
                        onSwipeLeft();
                    }
                }
            }
            else
            {
                if(Math.abs(diffy)>GESTURE_THRESHOULD && Math.abs(velocityy)>GESTURE_VELOCITY_THRESHOULD)
                {
                    if(diffy>0)
                    {
                         onSwipeBottom();
                    }
                    else
                    {
                        onSwipeTop();
                    }
                }
            }
        }
        catch(Exception e)
        {
            Log.d(TAG, ""+e.getMessage());
        }
        return false;           
    }

    public void onSwipeRight()
    {
        //Toast.makeText(this.getClass().get, "swipe right", Toast.LENGTH_SHORT).show();
        Log.i(TAG, "Right");
    }
    public void onSwipeLeft()
    {
        Log.i(TAG, "Left");
        //Toast.makeText(MyActivity.this, "swipe left", Toast.LENGTH_SHORT).show();
    }

    public void onSwipeTop()
    {
        Log.i(TAG, "Top");
        //Toast.makeText(MyActivity.this, "swipe top", Toast.LENGTH_SHORT).show();
    }

    public void onSwipeBottom()
    {
        Log.i(TAG, "Bottom");
        //Toast.makeText(MyActivity.this, "swipe bottom", Toast.LENGTH_SHORT).show();
    }   

  }

 }