Mathias Lin code working beautifully. However, you might want to consider changing this part inside drawPath method:
if (lngLat.length >= 2 && gp1.getLatitudeE6() > 0 && gp1.getLongitudeE6() > 0
&& gp2.getLatitudeE6() > 0 && gp2.getLongitudeE6() > 0) {
GeoPoint can be less than zero as well, I switch mine to:
if (lngLat.length >= 2 && gp1.getLatitudeE6() != 0 && gp1.getLongitudeE6() != 0
&& gp2.getLatitudeE6() != 0 && gp2.getLongitudeE6() != 0) {
Thank you :D