RxPicasso

public class RxPicasso {

    @NotNull
    public static Observable<Void> load(RequestCreator requestCreator, ImageView imageView) {
        return Observable.create(subscriber -> {
            requestCreator.into(imageView, new Callback() {
                @Override
                public void onSuccess() {
                    if (!subscriber.isUnsubscribed()) {
                        subscriber.onNext(null);
                    }
                }

                @Override
                public void onError() {
                    if (!subscriber.isUnsubscribed()) {
                        subscriber.onError(new Throwable("이미지 로딩 실패"));
                    }
                }
            });
        });
    }
}