MainPresenter.java

package com.patloew.rxlocationsample;

import android.location.Address;
import android.location.Location;
import android.util.Log;

import com.google.android.gms.location.LocationRequest;
import com.patloew.rxlocation.RxLocation;

import io.reactivex.Observable;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.CompositeDisposable;
import io.reactivex.schedulers.Schedulers;

/* Copyright 2016 Patrick Löwenstein
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License. */
public class MainPresenter {

    private final CompositeDisposable disposable = new CompositeDisposable();

    private final RxLocation rxLocation;
    private final LocationRequest locationRequest;

    private MainView view;

    public MainPresenter(RxLocation rxLocation) {
        this.rxLocation = rxLocation;

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

    public void attachView(MainView view) {
        this.view = view;
        startLocationRefresh();
    }

    public void detachView() {
        this.view = null;
        disposable.clear();
    }

    public void startLocationRefresh() {
        disposable.add(
                rxLocation.settings().checkAndHandleResolution(locationRequest)
                        .flatMapObservable(this::getAddressObservable)
                        .observeOn(AndroidSchedulers.mainThread())
                        .subscribe(view::onAddressUpdate, throwable -> Log.e("MainPresenter", "Error fetching location/address updates", throwable))
        );
    }

    private Observable<Address> getAddressObservable(boolean success) {
        if(success) {
            return rxLocation.location().updates(locationRequest)
                            .subscribeOn(Schedulers.io())
                            .observeOn(AndroidSchedulers.mainThread())
                            .doOnNext(view::onLocationUpdate)
                            .flatMap(this::getAddressFromLocation);

        } else {
            view.onLocationSettingsUnsuccessful();

            return rxLocation.location().lastLocation()
                            .doOnSuccess(view::onLocationUpdate)
                            .flatMapObservable(this::getAddressFromLocation);
        }
    }

    private Observable<Address> getAddressFromLocation(Location location) {
        return rxLocation.geocoding().fromLocation(location).toObservable()
                .subscribeOn(Schedulers.io());
    }


}