An abstract CompletableObserver that allows asynchronous cancellation by implementing Disposable.

All pre-implemented final methods are thread-safe.

Like all other consumers, DisposableCompletableObserver can be subscribed only once. Any subsequent attempt to subscribe it to a new source will yield an IllegalStateException with message "It is not allowed to subscribe with a(n) <class name> multiple times.".

Implementation of onStart(), onError(Throwable) and onComplete() are not allowed to throw any unchecked exceptions.

Example

Disposable d =
    Completable.complete().delay(1, TimeUnit.SECONDS)
    .subscribeWith(new DisposableMaybeObserver<Integer>() {
        @Override public void onStart() {
            System.out.println("Start!");
        }
        @Override public void onError(Throwable t) {
            t.printStackTrace();
        }
        @Override public void onComplete() {
            System.out.println("Done!");
        }
    });
// ...
d.dispose();