RxJava Thread.sleep in another thread

Question

How with use RxJava update UI every one second in Android? I'm trying to do something like this:

 for (int i = 0; i <10 ; i++) { //test
               rx.Observable.just(getSleep())
                        .subscribeOn(Schedulers.newThread())
                        .observeOn(AndroidSchedulers.mainThread())
                        .subscribe(v->updateTime());//update textView
        }

    private <T> int getSleep() {
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return 0;
    }

But Thread.sleep() doing in ui thread. What I to do wrong?

Answer 1

Observable.interval(1, TimeUnit.SECONDS) //emits item every second
            .observeOn(AndroidSchedulers.mainThread()) //switches thread from computation (interval's default) to UI
            .subscribe(i -> updateUI()); //update your textView

Answer 2

rx.Observable.just(getSleep())
                    .subscribeOn(Schedulers.newThread())
                    .observeOn(AndroidSchedulers.mainThread())
                    .subscribe(v->updateTime());//update textView

it's like

int stuff = getSleep();
rx.Observable.just(stuff)
                    .subscribeOn(Schedulers.newThread())
                    .observeOn(AndroidSchedulers.mainThread())
                    .subscribe(v->updateTime());//update textView

If your code is running in the UI Thread then getSleep() will be executed in the UI Thread. You'll have to defer your call (using fromCallable for example).

     rx.Observable.fromCallable(() -> getSleep())
                    .subscribeOn(Schedulers.newThread())
                    .observeOn(AndroidSchedulers.mainThread())
                    .subscribe(v->updateTime());//update textView