Java Code Examples for android.arch.lifecycle.LiveData#observeForever()

@SuppressWarnings("unchecked")
@Nullable
static <T> T getLiveDataValue(final LiveData<T> liveData, final long timeOutInSeconds)
        throws InterruptedException {
    final Object[] resultHolder = new Object[1];
    final CountDownLatch countDownLatch = new CountDownLatch(1);

    liveData.observeForever(new Observer<T>() {
        @Override
        public void onChanged(@Nullable T t) {
            resultHolder[0] = t;
            countDownLatch.countDown();
            liveData.removeObserver(this);
        }
    });
    countDownLatch.await(timeOutInSeconds, TimeUnit.SECONDS);
    if (resultHolder.length == 0) {
        throw new AssertionError("Unable to retrieve LiveData result");
    }
    return (T) resultHolder[0];
}
 

public static <T> T getValue(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(2, TimeUnit.SECONDS);
    //noinspection unchecked
    return (T) data[0];
}
 

public LiveData<List<Article>> getHeadlines(final Specification specs) {
    final LiveData<List<Article>> networkData = newsApiService.getHeadlines(specs);
    networkData.observeForever(new Observer<List<Article>>() {
        @Override
        public void onChanged(@Nullable List<Article> articles) {
            if (articles != null) {
                networkArticleLiveData.setValue(articles);
                networkData.removeObserver(this);
            }
        }
    });
    return headlinesDao.getArticleByCategory(specs.getCategory());
}
 

public LiveData<List<Source>> getSources(final Specification specs) {
    final LiveData<List<Source>> networkData = newsApiService.getSources(specs);
    networkData.observeForever(new Observer<List<Source>>() {
        @Override
        public void onChanged(@Nullable List<Source> sources) {
            if (sources != null) {
                networkSourceLiveData.setValue(sources);
                networkData.removeObserver(this);
            }
        }
    });
    return sourcesDao.getAllSources();
}
 

/**
 * Handle action Foo in the provided background thread with the provided
 * parameters.
 */
private void handleActionNext(final int currentIndex) {
    final LiveData<List<Article>> articlesLiveData = NewsRepository.getInstance(getApplicationContext()).getSaved();
    articlesLiveData.observeForever(new Observer<List<Article>>() {
        @Override
        public void onChanged(@Nullable List<Article> articles) {
            if (articles != null && articles.size() > currentIndex + 1) {
                handleUpdateWidgets(articles, currentIndex + 1);
                articlesLiveData.removeObserver(this);
            }
        }
    });
}
 

private void handleActionPrevious(final int currentIndex) {
    final LiveData<List<Article>> articlesLiveData = NewsRepository.getInstance(getApplicationContext()).getSaved();
    articlesLiveData.observeForever(new Observer<List<Article>>() {
        @Override
        public void onChanged(@Nullable List<Article> articles) {
            if (articles != null && articles.size() > 0 && currentIndex > 0) {
                handleUpdateWidgets(articles, currentIndex - 1);
                articlesLiveData.removeObserver(this);
            }
        }
    });
}
 

/**
 * Test run JQL 1.
 *
 * @throws InterruptedException the interrupted exception
 */
@Test
public void testRunJQL1() throws InterruptedException {
	LiveData<List<Person>> liveData = BindApp1DataSource.getInstance().getDaoPerson1().selectAll();
	
	liveData.observeForever(new Observer<List<Person>>() {
		
		@Override
		public void onChanged(List<Person> t) {
			log(">> observed changes for person. Now thera are %s", t.size());
			
		}
	});
	
	// https://www.adityathakker.com/android-content-observer-react-on-content-change/
	MyObserver myObserver = new MyObserver(new Handler());		
	getApplicationContext().getContentResolver().registerContentObserver(BindApp1ContentProvider.URI_PERSON_SELECT_ALL, true, myObserver);
	
	
	insertRows(10);
	
	
	Thread.sleep(2000);
}