How to use rxandroid to listen gps location update

Question

I started learning reactive programming these days. In my application, I have turned to use rxandroid for many cases that process data asynchronously. But I don't know how to apply to location listener. Is there any way to subscribe the user location change? Please give me an idea.

Answer 1

You can create Observables or Subject by using LocationListener and when getting callback in the onLocationChanged, just call onNext with the location object.

public final class LocationProvider implements onLocationChanged {
   private final PublishSubject<Location> latestLocation = PublishSubject.create();
   //...
   @Override
    public void onLocationChanged(Location location) {
        latestLocation.onNext(location);
    }
}

Then you can subscribe to it in a class that needs location.

There are also some open source libraries that you could use: Android-ReactiveLocation and cgeo

Also, see Observable-based API and unsubscribe issue

Hope this helps!

Answer 2

How about using this awesome library ? https://github.com/patloew/RxLocation

add this to build.gradle

compile 'com.patloew.rxlocation:rxlocation:1.0.4'

you may use this snippet from the above mentioned library to subscribe on location changes, I believe this is the simplest way

// Create one instance and share it
RxLocation rxLocation = new RxLocation(context);

LocationRequest locationRequest = LocationRequest.create()
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                .setInterval(5000);

rxLocation.location().updates(locationRequest)
        .flatMap(location -> rxLocation.geocoding().fromLocation(location).toObservable())
        .subscribe(address -> {
            /* do something */
        });