根据gps状态android可互换网络和GPS位置提供商

i would appreciate your help , if anyone can help me. i need to have an accurate location tracker in my app and i want it to act like this. it finds the first location of the person with network , meanwhile i start requesting GPS localisation. when gps gives me a location , i want to not listen anymore to network locations. After that i want to request a location from network only and only if Gps is not fixed(cant give me a location). When Gps is fixed again i want to stop listening to network,and this is the loop i want to implement since GPS is more acurate and i want to have network localisation as a backup. I Have seen this post , but i cant seem to understand how to adapt it to my needs,i would appreciate your help , if anyone can he