map view double tap event doesn't work

In my application i want to implement double tap event on map view.For this I'm using following code but doesn't seem to work.Please help me...
Thanks in advance!!
public class NooYawk extends MapActivity implements OnGestureListener, OnDoubleTapListener  {
    private MapView map=null;
    private MyLocationOverlay me=null;
    GeoPoint geoPoint;
    MapController controller;
    OverlayItem overlayItem;
    PushPinMapView pushPinMapView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        map=(MapView)findViewById(R.id.map);

        //  map.getController().setCenter(getPoint(40.76793169992044,-73.98180484771729));
        controller=map.getController();
        map.setStreetView(true);
        map.setBuiltInZoomControls(true);

        Drawable marker=getResources().getDrawable(R.drawable.blue);
        marker.setBounds(0, 0, marker.getIntrinsicWidth(),
                marker.getIntrinsicHeight());

        geoPoint=new GeoPoint((int)(19.182 *1E6 ),(int)(72.961 * 1E6));
        controller.animateTo(geoPoint);
        overlayItem=new OverlayItem(geoPoint, "Current loc","");
        List<Overlay> listOverlays= map.getOverlays();
        SitesOverlay sitesOverlay=new SitesOverlay(marker);
        sitesOverlay.addOverlay(overlayItem);
        listOverlays.add(s开发者_Go百科itesOverlay);
        controller.setZoom(6);

    }
@Override
    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }


    private class SitesOverlay extends ItemizedOverlay<OverlayItem> {
        private List<OverlayItem> items=new ArrayList<OverlayItem>();

        public SitesOverlay(Drawable marker) {
            super(marker);


        }

        @Override
        protected OverlayItem createItem(int i) {
            return(items.get(i));
        }

        @Override
        public void draw(Canvas canvas, MapView mapView,
                boolean shadow) {
            super.draw(canvas, mapView, shadow);

            boundCenterBottom(marker);
        }

        @Override
        public int size() {
            return(items.size());
        }

        public void addOverlay(OverlayItem overlay) {

            items.add(overlay);

            //System.out.println("success");

            populate();

        }
}



@Override
    public boolean onDown(MotionEvent e) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
            float velocityY) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void onLongPress(MotionEvent e) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
            float distanceY) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void onShowPress(MotionEvent e) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public boolean onDoubleTap(MotionEvent e) {
        controller.zoomIn();
        return false;
    }

    @Override
    public boolean onDoubleTapEvent(MotionEvent e) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public boolean onSingleTapConfirmed(MotionEvent e) {
        // TODO Auto-generated method stub
        return false;
    }

}

I believe you actually have to create a GestureDetector to use it: I might be wrong, but I don't see you actually doing that anywhere in your code. Take a look at this for an example.

You could create a GestureDetector to handle this action, but also you can implement some ticks like this (that works):

private long lastTouchTime = -1;

@Override
public boolean onTouchEvent(MotionEvent e, MapView mapView) {
  long thisTime = System.currentTimeMillis();
  // 250 in TimeMillis is a good interval limit for a double click
  if (thisTime - lastTouchTime < 250) {
     // this is a double touch / tap
     lastTouchTime = -1;
  }else {
     // this is a single touch / tap
     lastTouchTime = thisTime;
  }
...
}

hope it helps..