Examples with MediatorLiveData androidx.lifecycle.MediatorLiveData used on opensource projects

Example 1 with MediatorLiveData

use of androidx.lifecycle.MediatorLiveData in project zype-android by zype.

the class GalleryViewModel method getGalleryRows.

public LiveData<List<GalleryRow>> getGalleryRows(String parentPlaylistId) {
    if (data == null) {
        this.parentPlaylistId = parentPlaylistId;
        data = new MediatorLiveData<>();
        liveDataPlaylists = getPlaylists(parentPlaylistId);
        liveDataVideos = new HashMap<>();
        liveDataNestedPlaylists = new HashMap<>();
        data.addSource(liveDataPlaylists, new Observer<List<Playlist>>() {

            @Override
            public void onChanged(@Nullable List<Playlist> playlists) {
                Logger.d("onChanged(): Playlists, size=" + playlists.size());
                if (!playlists.isEmpty()) {
                    data.removeSource(liveDataPlaylists);
                }
                final List<GalleryRow> galleryRows = new ArrayList<>();
                for (final Playlist playlist : playlists) {
                    final GalleryRow row = new GalleryRow(playlist);
                    // Add video items to the row if playlist contains any video
                    if (playlist.playlistItemCount > 0) {
                        LiveData<List<Video>> playlistVideos = liveDataVideos.get(playlist.id);
                        if (playlistVideos == null) {
                            playlistVideos = getPlaylistVideos(playlist.id);
                            liveDataVideos.put(playlist.id, playlistVideos);
                            data.addSource(playlistVideos, new Observer<List<Video>>() {

                                @Override
                                public void onChanged(@Nullable List<Video> videos) {
                                    Logger.d("onChanged(): Videos (" + playlist.title + "), size=" + videos.size());
                                    row.videos = videos;
                                    if (allDataLoaded(galleryRows)) {
                                        data.setValue(galleryRows);
                                        ZypeApp.needToLoadData = false;
                                    }
                                }
                            });
                        }
                    } else // Otherwise add nested playlists
                    {
                        LiveData<List<Playlist>> nestedPlaylists = liveDataNestedPlaylists.get(playlist.id);
                        if (nestedPlaylists == null) {
                            nestedPlaylists = getPlaylists(playlist.id);
                            liveDataNestedPlaylists.put(playlist.id, nestedPlaylists);
                            data.addSource(nestedPlaylists, new Observer<List<Playlist>>() {

                                @Override
                                public void onChanged(@Nullable List<Playlist> playlists) {
                                    Logger.d("onChanged(): Nested playlists (" + playlist.title + "), size=" + playlists.size());
                                    if (playlists.isEmpty()) {
                                        if (playlistApiRequests.containsKey(playlist.id)) {
                                            if (playlistApiRequests.get(playlist.id)) {
                                                Logger.d("onChanged(): Nested playlists (" + playlist.title + "), wait for API response");
                                            } else {
                                                Logger.d("onChanged(): Nested playlists (" + playlist.title + "), row removed");
                                                galleryRows.remove(row);
                                            }
                                        } else {
                                            Logger.d("onChanged(): Nested playlists (" + playlist.title + "), row removed");
                                            galleryRows.remove(row);
                                        }
                                    } else {
                                        row.nestedPlaylists = playlists;
                                        playlistApiRequests.remove(playlist.id);
                                    }
                                    if (allDataLoaded(galleryRows)) {
                                        data.setValue(galleryRows);
                                        ZypeApp.needToLoadData = false;
                                    }
                                }
                            });
                        }
                    }
                    galleryRows.add(row);
                }
                data.setValue(galleryRows);
            }
        });
    }
    return data;
}

Example 2 with MediatorLiveData

use of androidx.lifecycle.MediatorLiveData in project Signal-Android by WhisperSystems.

the class LiveDataUtil method mapAsync.

/**
 * Runs the {@param backgroundFunction} on the supplied {@param executor}.
 * <p>
 * Regardless of the executor supplied, the background function is run serially.
 * <p>
 * The background function may not run for all {@param source} updates. Later updates taking priority.
 */
public static <A, B> LiveData<B> mapAsync(@NonNull Executor executor, @NonNull LiveData<A> source, @NonNull Function<A, B> backgroundFunction) {
    MediatorLiveData<B> outputLiveData = new MediatorLiveData<>();
    Executor liveDataExecutor = new SerialMonoLifoExecutor(executor);
    outputLiveData.addSource(source, currentValue -> {
        liveDataExecutor.execute(() -> {
            outputLiveData.postValue(backgroundFunction.apply(currentValue));
        });
    });
    return outputLiveData;
}

Example 3 with MediatorLiveData

use of androidx.lifecycle.MediatorLiveData in project Signal-Android by signalapp.

the class LiveDataUtil method mapAsync.

/**
 * Runs the {@param backgroundFunction} on the supplied {@param executor}.
 * <p>
 * Regardless of the executor supplied, the background function is run serially.
 * <p>
 * The background function may not run for all {@param source} updates. Later updates taking priority.
 */
public static <A, B> LiveData<B> mapAsync(@NonNull Executor executor, @NonNull LiveData<A> source, @NonNull Function<A, B> backgroundFunction) {
    MediatorLiveData<B> outputLiveData = new MediatorLiveData<>();
    Executor liveDataExecutor = new SerialMonoLifoExecutor(executor);
    outputLiveData.addSource(source, currentValue -> {
        liveDataExecutor.execute(() -> {
            outputLiveData.postValue(backgroundFunction.apply(currentValue));
        });
    });
    return outputLiveData;
}