What are the best practices for Location-based Android app's architecture?

Question

I want to know what are the best practices for Location-based Android app's architecture/workflow?

My current code uses several Activity and one backing Service, and several AsyncTask.

I start my Service as soon as my app is launched, I do all the HTTP callings and parsings in my Service. And I also wrote a subclass of AsyncTask to obtain user's location. I run the AsyncTask everytime I need to update user's location. The AyncTask calls LocationManager.requestLocationUpdates() and asks to get locations as fast as possible. My strategy for this is:
1. At first, I getLastKnownLocation for both GPS and network, and compare them using the method on http://developer.android.com/guide/topics/location/obtaining-user-location.html#BestEstimate.
2. When 3 GPS locations and 5 network locations is obtained, or one or both of GPS and network didn't respond in 1 minute, I stop the task.
3. I return the best estimate I have.

the Locating AsyncTask is run in the Service, and I set an AlarmService for 5 minutes to send my service an Intent to check whether I need to update user's location. My min interval between two AsyncTask is 10 minutes. User is able to request Location updates manually by simply pressing a button.

Above is how I implement the Location service into my app.
I need to know whether my practice is appropriate. If not what is wrong? If yes, is there anything that can be improved?

Answer 1

I think youy pretty much got it. I have very similar solution where I want "in and out" as soon as I can.

I implemented check for "accuracy" into my algoritm. I give service 1 minute from start to get BEST possible location or I will exit even earlier if I get 25m or better accuracy fix.

Also, I don't use AsyncTask for location itself - Service doesn't block thread, it get's and processes callbacks from LocationManager so I don't see why you want to do AsyncTask.

When I'm done with obtaining location and about to exit - then I call async task to process Http post to the server.

As far as interval - I give user options of 5/15/30/1hr and 1/2day. I use inexact alarm for this - supposedly better on battery.

Answer 2

This is not an answer per say , but here are some additional points. Reto Meier , in his Pro Android tips in Google IO suggested not using wi-fi if the battery was low.

This can also be extended to location. Let the user know his battery is too weak & the app wont be using GPS & network provider , instead it will be using the last known location which may be inaccurate.

You have not mentioned it, so I am going on the worst case scenario that you can not checking if the location providers are enabled. You need to check for the same and have an alert asking the user to enable location service if all are providers are disabled.