Can we make android.app.Service as lifecycle aware component

Question

all I get from the new Android Architecture Components is, if we make the component lifecycle aware then depending on the activity lifecycle the LifecycleObserver will react to the events. That reduces a lot of boilerplate code that we write in onCreate,onStop or onStart etc. activity or fragment lifecycle methods.

Now how to make an android service a lifecycle aware? So far I can see is we can create a service that extent android.arch.lifecycle.LifecycleService. However, I can't see any event related to bind and unbind while I am observing.

Code snippets

// MY BOUNDED service
public class MyService extends LifecycleService 
        implements LocationManager.LocationListener{

    private LocationManager mLocationManager;
    @Override
    public void onCreate() {
        super.onCreate();
        mLocationManager = LocationManager.getInstance(this, this);
        mLocationManager.addLocationListener(this);
    }

    @Override
    public void onLocationChanged(Location location) {
    }

    @Override
    public IBinder onBind(Intent intent) {
        super.onBind(intent);

    }

    @Override
    public boolean onUnbind(Intent intent) {
    }
    ...
}


public class LocationManager implements LifecycleObserver{
    public interface LocationListener {
        void onLocationChanged(Location location);
    }
    private LocationManager(LifecycleOwner lifecycleOwner, Context context){
        this.lifecycleOwner =lifecycleOwner;
        this.lifecycleOwner.getLifecycle().addObserver(this);
        this.context = context;
    }

    public static LocationAccessProcess getInstance(LifecycleOwner lifecycleOwner, Context context) {
        // just accessiong the object using static method not single ton actually, so don't mind for now
        return new LocationAccessProcess(lifecycleOwner, context);
    }


    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    public void startLocationUpdates() {
        // start getting location updates and update listener
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
    public void stopLocationUpdates() {
        // stop location updates
    }
}

I have few questions here

1. How i can observer on ON_BIND and ON_UNBIND events. as I would like to reduce my service code as well.
2. Am I doing any thing wrong, Can we release use lifecycle arch for services

Answer 1

From source code LifecycleService and ServiceLifecycleDispatcher

I think

• onCreate() is ON_CREATE event,

• onBind() , onStart() & onStartCommand() all are ON_START event,

• onDestroy() is ON_STOP and ON_DESTROY event.

Answer 2

The Service class really only has two lifecycle evens: ON_CREATE and ON_DESTROY . The binder based callbacks in the Service are not lifecycle callbacks, so they cannot be observed directly via LifecycleObserver .

Kudos to @vivart for digging into the code. He's correct: when bind happens, ON_START is sent. However, there is not a life cycle event for unbind, so your service need to override those methods to handle them as events.