CODEWITHSUNDEEP
androidtimerrx-java
ramden
ramden

Reputation: 838

RxJava 1 Android: How to create a sequence of timers?

I want to implement the following with RxJava on android:

The class TimeUnit contains a list of class Sequence (TimeUnit has a list of Sequences) that have a integer property "length".

The sequences have a 1 - 10 seconds length.

When the TimeUnit run() method is called the timer starts and executes the firs sequence in the list. After that sequence 2 etc.

Example:

TimeUnit
  - Sequence 1 -> 10 seconds
  - Sequence 2 -> 4 seconds
  - Sequence 3 -> 5 seconds

How to achieve this output in RxJava :

TimeUnit started
Starting "Sequence 1"
Sequence 1 -> second 1
Sequence 1 -> second 2
Sequence 1 -> second 3
...
Starting "Sequence 2"
Sequence 2 -> second 1
....
TimeUnit completed in 19 seconds

I tried with many Rx Techniques like interval(), concatMap(), flatMap() ... but no success.

How would you setup a skeleton for this? Is Rx able to concat intervals?

I have no codesnippet as no solution worked

Upvotes: 2

Views: 153

Answers (1)

Leandro Borges Ferreira
Leandro Borges Ferreira

Reputation: 12782

If you don't mind using a little bit of code that is not from RxJava, you can use this solution:

public Observable<String> createObservable(TimeUnit timeUnit){
        Handler handler = new Handler();

        Observable<String> observable = Observable.create(new Observable.OnSubscribe<String>() {
            @Override
            public void call(Subscriber<? super String> subscriber) {
                for(Sequence sequence : TimeUnit.getSequenceList()){
                    Runnable runnable = () -> {
                        subscriber.onNext(sequence.length);
                    };

                    handler.postDelayed(runnable, sequence.lenth);
                }
            }
        });

        return observable;
    }

It's just a example, adapt to your needs.

I think it's a good approach because you are trying to do is not very trivial, so a little bit of imperative code won't hurt.

Happy coding!

Upvotes: 1

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