如果另一个源在一段时间内不是项目,则RxJava仅发出项目

时间:2017-02-21 11:41:56

标签: java rx-java rx-android

有两个可观察的

Observable<Void> cancelButtonClick
            = RxView.clicks(btnCancel);
Observable<Void> actionButtonClick
            = RxView.clicks(btnSomeAction)

问题

尝试从actionButtonClick流发出值,如果cancelButtonClick流不会为 10秒发出

尝试:

final DateTime[] lastCancelDate = new DateTime[1];
cancelButtonClick
       .map(new Func1<Void, DateTime>() {
            @Override
            public DateTime call(Void aVoid) {
                return DateTime.now();
            }
        })
        .subscribe(new Action1<DateTime>() {
           @Override
            public void call(DateTime dateTime) {
                lastCancelDate[0] = dateTime;
            }
        });

actionButtonClick                
        .delay(10, TimeUnit.SECONDS)
        .filter(new Func1<Void, Boolean>() {
            @Override
            public Boolean call(Void aVoid) {
             return 
                lastCancelDate[0] == null 
                || (new Duration(lastCancelDate[0], DateTime.now()).getStandardSeconds()) 
                   > 10;
            }
        })
        .doOnNext(new Action1<Void>() {
            @Override
            public void call(Void aVoid) {
                lastCancelDate[0] = null;
            }
        })
        .subscribe(new Action1<Void>() {
            @Override
            public void call(Void aVoid) {
                Log.d("ACTIONII", "Got Action");
            }
        });

它有效,但应该有更好的方法。

1 个答案:

答案 0 :(得分:0)

所以如果actionButtonClick在未来10秒内没有发出项目,你想阻止发出cancelButtonClick吗?

首先,您可以使用BehaviorSubject

来改善您的解决方案
BehaviorSubject<DateTime> lastCancelSubject = BehaviorSubject.create();

cancelButtonClick
        .map(new Func1<Void, DateTime>() {
            @Override
            public DateTime call(Void aVoid) {
                return DateTime.now();
            }
        })
        .subscribe(lastCancelSubject);

actionButtonClick
        .delay(10, TimeUnit.SECONDS)
        .filter(new Func1<Void, Boolean>() {
            @Override
            public Boolean call(Void aVoid) {
                return
                        lastCancelDate[0] == null
                                || (new Duration(lastCancelSubject.getValue(), DateTime.now()).getStandardSeconds())
                                > 10;
            }
        })
        .subscribe(new Action1<Void>() {
            @Override
            public void call(Void aVoid) {
                Log.d("ACTIONII", "Got Action");
            }
        });

虽然rx-java提供了几种方法来实现这一点,但我会声明另一个Observable

final Observable<Boolean> iscancelledObservable = cancelButtonClick
        .buffer(10, TimeUnit.SECONDS)
        .first()
        .map(new Func1<List<Void>, Boolean>() {
            @Override
            public Boolean call(List<Void> voids) {
                return voids.size() > 0;
            }
        });

actionButtonClick
        .flatMap(new Func1<Void, Observable<Boolean>>() {
            @Override
            public Observable<Boolean> call(Void aVoid) {
                return iscancelledObservable;
            }
        })
        .filter(new Func1<Boolean, Boolean>() {
            @Override
            public Boolean call(Boolean aBoolean) {
                return !aBoolean;
            }
        })
        .subscribe(new Action1<Void>() {
            @Override
            public void call(Void aVoid) {
                Log.d("ACTIONII", "Got Action");
            }
        });

此解决方案功能更强,不依赖于存储状态。