How does one implement drag and drop for Android marker?

Here is a sample project from one of my books showing drag-and-drop movement of markers on a Google Map in Android.

In a nutshell, it uses onTouchEvent() to detect when the user touches and holds their finger near a marker. It then removes the marker from the overlay, but puts the same image over top of the map using RelativeLayout. Then, on "move" touch events, the image is moved (faster than forcing the whole overlay to redraw). When the finger is lifted, the image is removed, but the marker is put back in the overlay at the new spot.

Implement Google Maps Android API v2, refer this: https://developers.google.com/maps/documentation/android/ and set on GoogleMap object setOnMarkerDragListener. For Ex:

map.setOnMarkerDragListener(new OnMarkerDragListener() {
        @Override
        public void onMarkerDragStart(Marker arg0) {
            // TODO Auto-generated method stub
            Log.d("System out", "onMarkerDragStart..."+arg0.getPosition().latitude+"..."+arg0.getPosition().longitude);
        }

        @SuppressWarnings("unchecked")
        @Override
        public void onMarkerDragEnd(Marker arg0) {
            // TODO Auto-generated method stub
            Log.d("System out", "onMarkerDragEnd..."+arg0.getPosition().latitude+"..."+arg0.getPosition().longitude);

            map.animateCamera(CameraUpdateFactory.newLatLng(arg0.getPosition()));
        }

        @Override
        public void onMarkerDrag(Marker arg0) {
            // TODO Auto-generated method stub
            Log.i("System out", "onMarkerDrag...");
        }
    });

//Don't forget to Set draggable(true) to marker, if this not set marker does not drag.

map.addMarker(new MarkerOptions()
    .position(crntLocationLatLng)
    .icon(BitmapDescriptorFactory.fromResource(R.drawable.icon_my_location))
    .draggable(true));