Java Code Examples for androidx.lifecycle.LiveData#observeForever()

public void waitForEdit(UUID uuid) {
    final WorkManager workManager = WorkManager.getInstance(getApplication());
    LiveData<WorkInfo> liveData = workManager.getWorkInfoByIdLiveData(uuid);
    liveData.observeForever(new Observer<WorkInfo>() {
        @Override
        public void onChanged(WorkInfo workInfo) {
            if (workInfo.getState() == WorkInfo.State.SUCCEEDED) {
                final Data data = workInfo.getOutputData();
                final String threadId = data.getString("threadId");
                if (threadId != null && !ThreadViewModel.this.threadId.equals(threadId)) {
                    LOGGER.info("redirecting to thread {}", threadId);
                    threadViewRedirect.postValue(new Event<>(threadId));
                }
                liveData.removeObserver(this);
            } else if (workInfo.getState() == WorkInfo.State.FAILED) {
                liveData.removeObserver(this);
            }
        }
    });
}
 

/**
 * Get the value from a LiveData object. We're waiting for LiveData to emit, for 2 seconds.
 * Once we got a notification via onChanged, we stop observing.
 */
public static <T> T getValue(final LiveData<T> liveData) throws InterruptedException {
  final Object[] data = new Object[1];
  final CountDownLatch latch = new CountDownLatch(1);
  Observer<T> observer = new Observer<T>() {
    @Override
    public void onChanged(@Nullable T o) {
      data[0] = o;
      latch.countDown();
      liveData.removeObserver(this);
    }
  };
  liveData.observeForever(observer);
  latch.await(2, TimeUnit.SECONDS);
  //noinspection unchecked
  return (T) data[0];
}
 

/**
 * Get the value from a LiveData object. We're waiting for LiveData to emit, for 2 seconds.
 * Once we got a notification via onChanged, we stop observing.
 */
public static <T> T getValue(final LiveData<T> liveData) throws InterruptedException {
    final Object[] data = new Object[1];
    final CountDownLatch latch = new CountDownLatch(1);
    Observer<T> observer = new Observer<T>() {
        @Override
        public void onChanged(@Nullable T o) {
            data[0] = o;
            latch.countDown();
            liveData.removeObserver(this);
        }
    };
    liveData.observeForever(observer);
    latch.await(2, TimeUnit.SECONDS);
    //noinspection unchecked
    return (T) data[0];
}
 

private LiveData<RemoteResource<MoodleToken>> getToken() {

        String tokenStr = ApplicationManager.userCredentials.getMoodleToken();
        MutableLiveData<RemoteResource<MoodleToken>> token = new MutableLiveData<>();

        token.setValue(RemoteResource.loading(new MoodleToken(tokenStr)));

        LiveData<ApiResponse<MoodleToken>> apiResponseLiveData = moodleWebService.getToken(ApplicationManager.userCredentials.getUsername(), ApplicationManager.userCredentials.getPassword());
        apiResponseLiveData.observeForever(new Observer<ApiResponse<MoodleToken>>() {
            @Override
            public void onChanged(@Nullable ApiResponse<MoodleToken> moodleTokenApiResponse) {
                if (moodleTokenApiResponse != null) {
                    MoodleToken moodleToken = moodleTokenApiResponse.body;
                    if (moodleTokenApiResponse.isSuccessful() && moodleToken != null && moodleToken.getToken() != null && !moodleToken.getToken().isEmpty()) {
                        ApplicationManager.userCredentials.setMoodleToken(moodleToken.getToken());
                        token.setValue(RemoteResource.success(moodleToken));
                    } else
                        token.setValue(RemoteResource.error(context.getString(R.string.moodle_error_cant_get_token), moodleTokenApiResponse.body));

                    apiResponseLiveData.removeObserver(this);
                }
            }
        });
        return token;
    }
 

private <T> T getValue(@NonNull LiveData<T> liveData) throws InterruptedException {
    final Object[] data = new Object[1];
    CountDownLatch latch = new CountDownLatch(1);
    Observer<T> observer = new Observer<T>() {
        @Override
        public void onChanged(@Nullable T o) {
            data[0] = o;
            latch.countDown();
            liveData.removeObserver(this);
        }
    };
    liveData.observeForever(observer);
    latch.await(TIME_OUT, TimeUnit.SECONDS);
    //noinspection unchecked
    return (T) data[0];
}
 

/**
 * Observes and then instantly un-observes the supplied live data.
 * <p>
 * This will therefore only work in conjunction with {@link LiveDataRule}.
 */
public static <T> T getValue(final LiveData<T> liveData) {
  AtomicReference<T> data     = new AtomicReference<>();
  Observer<T>        observer = data::set;

  liveData.observeForever(observer);
  liveData.removeObserver(observer);

  return data.get();
}
 

public static  <T> void assertNoValue(final LiveData<T> liveData) {
  AtomicReference<Boolean> data     = new AtomicReference<>(false);
  Observer<T>              observer = newValue -> data.set(true);

  liveData.observeForever(observer);
  liveData.removeObserver(observer);

  assertFalse("Expected no value", data.get());
}
 

public static <T> void observeUntilFinished(final LiveData<WorkInfo> liveData,
    final Observer<WorkInfo> observer) {
  liveData.observeForever(new Observer<WorkInfo>() {
    @Override
    public void onChanged(WorkInfo workInfo) {
      if (workInfo != null && workInfo.getState().isFinished()) {
        Log.d("observeOnce", "Removing observer, work finished.");
        liveData.removeObserver(this);
      }
      observer.onChanged(workInfo);
    }
  });
}
 

public static <T> TestObserver<T> test(LiveData<T> liveData) {
  TestObserver<T> observer = new TestObserver<>();
  liveData.observeForever(observer);
  return observer;
}
 

public void bind(@NonNull LiveData<WeekState> weekStateLiveData) {
	this.weekStateLiveData = weekStateLiveData;
	weekStateLiveData.observeForever(this);
}