RxJava：如何将复杂的 if 语句转换为响应式流？

Question

I am implementing an app introduction and waiver that should appear before the user can access the MainActivity of my Android app. If the user has not accepted the waiver or gone through the app introduction, then my IntroNavigator kicks them back to those activities.

How can I rxify my redirectIfNecessary() method in a more functional manner, instead of the imperative approach I implemented below.

IntroNavigatorImpl.java

public class IntroNavigatorImpl implements IntroNavigator {
    WeakReference<Activity> activityWeakReference;
    CloudPrefsRepo cloudPrefsRepo;

    public IntroNavigatorImpl(Activity activity, CloudPrefsRepo cloudPrefsRepo) {
        this.activityWeakReference = new WeakReference<>(activity);
        this.cloudPrefsRepo = cloudPrefsRepo;
    }

    @Override
    public void redirectIfNecessary() {
        final boolean shouldShowAppIntro = cloudPrefsRepo.shouldShowAppIntro()
           .toObservable().toBlocking().first();
        final boolean shouldShowWaiver = cloudPrefsRepo.shouldShowWaiver()
           .toObservable().toBlocking().first();

        if (shouldShowAppIntro) {
            showAppIntro();
            finishActivity();
        } else if (shouldShowWaiver) {
            showWaiver();
            finishActivity();
        } else {
            //do nothing
        }
    }


    @Override
    public void showWaiver() {
        //launch waiver activity
    }

    @Override
    public void showAppIntro() {
        //launch app intro activity
    }

    public void finishActivity() {
        if (activityWeakReference.get() != null) {
            activityWeakReference.get().finish();
        }
    }
}

CloudPrefsRepo.java

public interface 
    /**
     * Whether to show the app intro.
     */
    Single<Boolean> shouldShowAppIntro();

    /**
     * Whether to show the waiver. If the user has already 
     * accepted this waiver, then it shouldn't be shown.
     */
    Single<Boolean> shouldShowWaiver();

Answer 1

Edit Based on comment:

It's not the prettiest (I'm leaning towards there not being a good reactive way to do this)

final Action0 showInfoAction = new Action0() {
        @Override
        public void call() {
            showAppIntro();
            finishActivity();
        }
    };


    final Action0 showWaiverAction = new Action0() {
        @Override
        public void call() {
            showWaiver();
            finishActivity();
        }
    };

    final Action0 blankAction = new Action0() {
        @Override
        public void call() {

        }
    };

    Observable.zip(shouldShowInfo, shouldShowWaiver, new Func2<Boolean, Boolean,  Action0>() {
        @Override
        public  Action0 call(Boolean shoudlShowInfo, Boolean shouldShowWaiver) {
            if (shoudlShowInfo) {
                return showInfoAction;
            } else if (shouldShowWaiver) {
                return showWaiverAction;
            } else {
                return blankAction;
            }
        }
    }).subscribe(new Action1<Action0>() {
        @Override
        public void call(Action0 action0) {
            action0.call();
        }
    });