BroadcastObservable.java

package licola.demo.com.huabandemo.Observable;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Looper;

import licola.demo.com.huabandemo.Util.Logger;
import rx.Observable;
import rx.Scheduler;
import rx.Subscriber;
import rx.Subscription;
import rx.android.schedulers.AndroidSchedulers;
import rx.functions.Action0;
import rx.subscriptions.Subscriptions;

/**
 * Created by hanks on 15-11-29.
 */
public class BroadcastObservable implements Observable.OnSubscribe<Boolean> {

    private final Context context;

    public static Observable<Boolean> fromConnectivityManager(Context context) {
        return Observable.create(new BroadcastObservable(context))
                .share();
    }

    public BroadcastObservable(Context context) {
        this.context = context;
    }

    @Override
    public void call(Subscriber<? super Boolean> subscriber) {
        BroadcastReceiver receiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                Logger.d();
                subscriber.onNext(isConnectedToInternet());
            }
        };

        context.registerReceiver(receiver, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));

        subscriber.add(unsubscribeInUiThread(() -> context.unregisterReceiver(receiver)));
    }

    private boolean isConnectedToInternet() {
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        Logger.d("isConnectedToInternet ="+networkInfo.isConnected() );
        return networkInfo != null && networkInfo.isConnected();
    }

    private static Subscription unsubscribeInUiThread(final Action0 unsubscribe) {
        return Subscriptions.create(() -> {
            if (Looper.getMainLooper() == Looper.myLooper()) {
                unsubscribe.call();
            } else {
                final Scheduler.Worker inner = AndroidSchedulers.mainThread().createWorker();
                inner.schedule(() -> {
                    unsubscribe.call();
                    inner.unsubscribe();
                });
            }
        });
    }

}