NewPipe/app/src/main/java/org/schabi/newpipe/fragments/list/feed/FeedFragment.java

446 lines
16 KiB
Java

package org.schabi.newpipe.fragments.list.feed;
import android.os.Bundle;
import android.os.Handler;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.ActionBar;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.view.ViewGroup;
import org.reactivestreams.Subscriber;
import org.reactivestreams.Subscription;
import org.schabi.newpipe.R;
import org.schabi.newpipe.database.subscription.SubscriptionEntity;
import org.schabi.newpipe.extractor.InfoItem;
import org.schabi.newpipe.extractor.NewPipe;
import org.schabi.newpipe.extractor.channel.ChannelInfo;
import org.schabi.newpipe.extractor.exceptions.ExtractionException;
import org.schabi.newpipe.fragments.list.BaseListFragment;
import org.schabi.newpipe.fragments.subscription.SubscriptionService;
import org.schabi.newpipe.report.UserAction;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import io.reactivex.Flowable;
import io.reactivex.MaybeObserver;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.CompositeDisposable;
import io.reactivex.disposables.Disposable;
import io.reactivex.functions.Action;
import io.reactivex.functions.Consumer;
import io.reactivex.functions.Predicate;
import io.reactivex.schedulers.Schedulers;
public class FeedFragment extends BaseListFragment<List<SubscriptionEntity>, Void> {
private static final int OFF_SCREEN_ITEMS_COUNT = 3;
private static final int MIN_ITEMS_INITIAL_LOAD = 8;
private int FEED_LOAD_COUNT = MIN_ITEMS_INITIAL_LOAD;
private int subscriptionPoolSize;
private SubscriptionService subscriptionService;
private AtomicBoolean allItemsLoaded = new AtomicBoolean(false);
private HashSet<String> itemsLoaded = new HashSet<>();
private final AtomicInteger requestLoadedAtomic = new AtomicInteger();
private CompositeDisposable compositeDisposable = new CompositeDisposable();
private Disposable subscriptionObserver;
private Subscription feedSubscriber;
/*//////////////////////////////////////////////////////////////////////////
// Fragment LifeCycle
//////////////////////////////////////////////////////////////////////////*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
subscriptionService = SubscriptionService.getInstance();
FEED_LOAD_COUNT = howManyItemsToLoad();
}
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_feed, container, false);
}
@Override
public void onPause() {
super.onPause();
disposeEverything();
}
@Override
public void onResume() {
super.onResume();
if (wasLoading.get()) doInitialLoadLogic();
}
@Override
public void onDestroy() {
super.onDestroy();
disposeEverything();
subscriptionService = null;
compositeDisposable = null;
subscriptionObserver = null;
feedSubscriber = null;
}
@Override
public void onDestroyView() {
// Do not monitor for updates when user is not viewing the feed fragment.
// This is a waste of bandwidth.
disposeEverything();
super.onDestroyView();
}
/*@Override
protected RecyclerView.LayoutManager getListLayoutManager() {
boolean isPortrait = getResources().getDisplayMetrics().heightPixels > getResources().getDisplayMetrics().widthPixels;
return new GridLayoutManager(activity, isPortrait ? 1 : 2);
}*/
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
ActionBar supportActionBar = activity.getSupportActionBar();
if (supportActionBar != null) {
supportActionBar.setTitle(R.string.fragment_whats_new);
}
}
@Override
public void reloadContent() {
resetFragment();
super.reloadContent();
}
/*//////////////////////////////////////////////////////////////////////////
// StateSaving
//////////////////////////////////////////////////////////////////////////*/
@Override
public void writeTo(Queue<Object> objectsToSave) {
super.writeTo(objectsToSave);
objectsToSave.add(allItemsLoaded);
objectsToSave.add(itemsLoaded);
}
@Override
@SuppressWarnings("unchecked")
public void readFrom(@NonNull Queue<Object> savedObjects) throws Exception {
super.readFrom(savedObjects);
allItemsLoaded = (AtomicBoolean) savedObjects.poll();
itemsLoaded = (HashSet<String>) savedObjects.poll();
}
/*//////////////////////////////////////////////////////////////////////////
// Feed Loader
//////////////////////////////////////////////////////////////////////////*/
@Override
public void startLoading(boolean forceLoad) {
if (DEBUG) Log.d(TAG, "startLoading() called with: forceLoad = [" + forceLoad + "]");
if (subscriptionObserver != null) subscriptionObserver.dispose();
if (allItemsLoaded.get()) {
if (infoListAdapter.getItemsList().size() == 0) {
showEmptyState();
} else {
showListFooter(false);
hideLoading();
}
isLoading.set(false);
return;
}
isLoading.set(true);
showLoading();
showListFooter(true);
subscriptionObserver = subscriptionService.getSubscription()
.onErrorReturnItem(Collections.<SubscriptionEntity>emptyList())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<List<SubscriptionEntity>>() {
@Override
public void accept(List<SubscriptionEntity> subscriptionEntities) throws Exception {
handleResult(subscriptionEntities);
}
}, new Consumer<Throwable>() {
@Override
public void accept(Throwable throwable) throws Exception {
onError(throwable);
}
});
}
@Override
public void handleResult(@android.support.annotation.NonNull List<SubscriptionEntity> result) {
super.handleResult(result);
if (result.isEmpty()) {
infoListAdapter.clearStreamItemList();
showEmptyState();
return;
}
subscriptionPoolSize = result.size();
Flowable.fromIterable(result)
.observeOn(AndroidSchedulers.mainThread())
.subscribe(getSubscriptionObserver());
}
/**
* Responsible for reacting to user pulling request and starting a request for new feed stream.
* <p>
* On initialization, it automatically requests the amount of feed needed to display
* a minimum amount required (FEED_LOAD_SIZE).
* <p>
* Upon receiving a user pull, it creates a Single Observer to fetch the ChannelInfo
* containing the feed streams.
**/
private Subscriber<SubscriptionEntity> getSubscriptionObserver() {
return new Subscriber<SubscriptionEntity>() {
@Override
public void onSubscribe(Subscription s) {
if (feedSubscriber != null) feedSubscriber.cancel();
feedSubscriber = s;
int requestSize = FEED_LOAD_COUNT - infoListAdapter.getItemsList().size();
if (wasLoading.getAndSet(false)) requestSize = FEED_LOAD_COUNT;
boolean hasToLoad = requestSize > 0;
if (hasToLoad) {
requestLoadedAtomic.set(infoListAdapter.getItemsList().size());
requestFeed(requestSize);
}
isLoading.set(hasToLoad);
}
@Override
public void onNext(SubscriptionEntity subscriptionEntity) {
if (!itemsLoaded.contains(subscriptionEntity.getServiceId() + subscriptionEntity.getUrl())) {
subscriptionService.getChannelInfo(subscriptionEntity)
.observeOn(AndroidSchedulers.mainThread())
.onErrorComplete(new Predicate<Throwable>() {
@Override
public boolean test(@io.reactivex.annotations.NonNull Throwable throwable) throws Exception {
return FeedFragment.super.onError(throwable);
}
})
.subscribe(getChannelInfoObserver(subscriptionEntity.getServiceId(), subscriptionEntity.getUrl()));
} else {
requestFeed(1);
}
}
@Override
public void onError(Throwable exception) {
FeedFragment.this.onError(exception);
}
@Override
public void onComplete() {
if (DEBUG) Log.d(TAG, "getSubscriptionObserver > onComplete() called");
}
};
}
/**
* On each request, a subscription item from the updated table is transformed
* into a ChannelInfo, containing the latest streams from the channel.
* <p>
* Currently, the feed uses the first into from the list of streams.
* <p>
* If chosen feed already displayed, then we request another feed from another
* subscription, until the subscription table runs out of new items.
* <p>
* This Observer is self-contained and will dispose itself when complete. However, this
* does not obey the fragment lifecycle and may continue running in the background
* until it is complete. This is done due to RxJava2 no longer propagate errors once
* an observer is unsubscribed while the thread process is still running.
* <p>
* To solve the above issue, we can either set a global RxJava Error Handler, or
* manage exceptions case by case. This should be done if the current implementation is
* too costly when dealing with larger subscription sets.
*
* @param url + serviceId to put in {@link #allItemsLoaded} to signal that this specific entity has been loaded.
*/
private MaybeObserver<ChannelInfo> getChannelInfoObserver(final int serviceId, final String url) {
return new MaybeObserver<ChannelInfo>() {
private Disposable observer;
@Override
public void onSubscribe(Disposable d) {
observer = d;
compositeDisposable.add(d);
isLoading.set(true);
}
// Called only when response is non-empty
@Override
public void onSuccess(final ChannelInfo channelInfo) {
if (infoListAdapter == null || channelInfo.related_streams.isEmpty()) {
onDone();
return;
}
final InfoItem item = channelInfo.related_streams.get(0);
// Keep requesting new items if the current one already exists
boolean itemExists = doesItemExist(infoListAdapter.getItemsList(), item);
if (!itemExists) {
infoListAdapter.addInfoItem(item);
//updateSubscription(channelInfo);
} else {
requestFeed(1);
}
onDone();
}
@Override
public void onError(Throwable exception) {
showSnackBarError(exception, UserAction.SUBSCRIPTION, NewPipe.getNameOfService(serviceId), url, 0);
requestFeed(1);
onDone();
}
// Called only when response is empty
@Override
public void onComplete() {
onDone();
}
private void onDone() {
if (observer.isDisposed()) {
return;
}
itemsLoaded.add(serviceId + url);
compositeDisposable.remove(observer);
int loaded = requestLoadedAtomic.incrementAndGet();
if (loaded >= Math.min(FEED_LOAD_COUNT, subscriptionPoolSize)) {
requestLoadedAtomic.set(0);
isLoading.set(false);
}
if (itemsLoaded.size() == subscriptionPoolSize) {
if (DEBUG) Log.d(TAG, "getChannelInfoObserver > All Items Loaded");
allItemsLoaded.set(true);
showListFooter(false);
isLoading.set(false);
hideLoading();
if (infoListAdapter.getItemsList().size() == 0) {
showEmptyState();
}
}
}
};
}
@Override
protected void loadMoreItems() {
isLoading.set(true);
delayHandler.removeCallbacksAndMessages(null);
// Add a little of a delay when requesting more items because the cache is so fast,
// that the view seems stuck to the user when he scroll to the bottom
delayHandler.postDelayed(new Runnable() {
@Override
public void run() {
requestFeed(FEED_LOAD_COUNT);
}
}, 300);
}
@Override
protected boolean hasMoreItems() {
return !allItemsLoaded.get();
}
private final Handler delayHandler = new Handler();
private void requestFeed(final int count) {
if (DEBUG) Log.d(TAG, "requestFeed() called with: count = [" + count + "], feedSubscriber = [" + feedSubscriber + "]");
if (feedSubscriber == null) return;
isLoading.set(true);
delayHandler.removeCallbacksAndMessages(null);
feedSubscriber.request(count);
}
/*//////////////////////////////////////////////////////////////////////////
// Utils
//////////////////////////////////////////////////////////////////////////*/
private void resetFragment() {
if (DEBUG) Log.d(TAG, "resetFragment() called");
if (subscriptionObserver != null) subscriptionObserver.dispose();
if (compositeDisposable != null) compositeDisposable.clear();
if (infoListAdapter != null) infoListAdapter.clearStreamItemList();
delayHandler.removeCallbacksAndMessages(null);
requestLoadedAtomic.set(0);
allItemsLoaded.set(false);
showListFooter(false);
itemsLoaded.clear();
}
private void disposeEverything() {
if (subscriptionObserver != null) subscriptionObserver.dispose();
if (compositeDisposable != null) compositeDisposable.clear();
if (feedSubscriber != null) feedSubscriber.cancel();
delayHandler.removeCallbacksAndMessages(null);
}
private boolean doesItemExist(final List<InfoItem> items, final InfoItem item) {
for (final InfoItem existingItem : items) {
if (existingItem.info_type == item.info_type &&
existingItem.service_id == item.service_id &&
existingItem.name.equals(item.name) &&
existingItem.url.equals(item.url)) return true;
}
return false;
}
private int howManyItemsToLoad() {
int heightPixels = getResources().getDisplayMetrics().heightPixels;
int itemHeightPixels = activity.getResources().getDimensionPixelSize(R.dimen.video_item_search_height);
int items = itemHeightPixels > 0 ? heightPixels / itemHeightPixels + OFF_SCREEN_ITEMS_COUNT : MIN_ITEMS_INITIAL_LOAD;
return Math.max(MIN_ITEMS_INITIAL_LOAD, items);
}
/*//////////////////////////////////////////////////////////////////////////
// Fragment Error Handling
//////////////////////////////////////////////////////////////////////////*/
@Override
public void showError(String message, boolean showRetryButton) {
resetFragment();
super.showError(message, showRetryButton);
}
@Override
protected boolean onError(Throwable exception) {
if (super.onError(exception)) return true;
int errorId = exception instanceof ExtractionException ? R.string.parsing_error : R.string.general_error;
onUnrecoverableError(exception, UserAction.SOMETHING_ELSE, "none", "Requesting feed", errorId);
return true;
}
}