Add lazy loading to feed item list (#7091)

app/src/main/java/de/danoeh/antennapod/ui/screen/download/DownloadLogAdapter.java

@@ -98,7 +98,7 @@ public class DownloadLogAdapter extends BaseAdapter {
                 if (status.getFeedfileType() == Feed.FEEDFILETYPE_FEED) {
                     holder.secondaryActionButton.setOnClickListener(v -> {
                         holder.secondaryActionButton.setVisibility(View.INVISIBLE);
-                        Feed feed = DBReader.getFeed(status.getFeedfileId());
+                        Feed feed = DBReader.getFeed(status.getFeedfileId(), false, 0, 0);
                         if (feed == null) {
                             Log.e(TAG, "Could not find feed for feed id: " + status.getFeedfileId());
                             return;

app/src/main/java/de/danoeh/antennapod/ui/screen/download/DownloadLogDetailsDialog.java

@@ -28,7 +28,7 @@ public class DownloadLogDetailsDialog extends MaterialAlertDialogBuilder {
                 url = media.getDownloadUrl();
             }
         } else if (status.getFeedfileType() == Feed.FEEDFILETYPE_FEED) {
-            Feed feed = DBReader.getFeed(status.getFeedfileId());
+            Feed feed = DBReader.getFeed(status.getFeedfileId(), false, 0, 0);
             if (feed != null) {
                 url = feed.getDownloadUrl();
             }

app/src/main/java/de/danoeh/antennapod/ui/screen/feed/FeedInfoFragment.java

@@ -168,7 +168,7 @@ public class FeedInfoFragment extends Fragment implements MaterialToolbar.OnMenu
     public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
         long feedId = getArguments().getLong(EXTRA_FEED_ID);
         disposable = Maybe.create((MaybeOnSubscribe<Feed>) emitter -> {
-            Feed feed = DBReader.getFeed(feedId);
+            Feed feed = DBReader.getFeed(feedId, false, 0, 0);
             if (feed != null) {
                 emitter.onSuccess(feed);
             } else {

app/src/main/java/de/danoeh/antennapod/ui/screen/feed/FeedItemlistFragment.java

@@ -17,6 +17,7 @@ import android.widget.Toast;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.content.res.AppCompatResources;
+import androidx.core.util.Pair;
 import androidx.fragment.app.Fragment;
 import androidx.recyclerview.widget.RecyclerView;
 
@@ -49,7 +50,6 @@ import de.danoeh.antennapod.event.FeedEvent;
 import de.danoeh.antennapod.ui.MenuItemUtils;
 import de.danoeh.antennapod.storage.database.DBReader;
 import de.danoeh.antennapod.storage.database.DBWriter;
-import de.danoeh.antennapod.storage.database.FeedItemPermutors;
 import de.danoeh.antennapod.ui.common.IntentUtils;
 import de.danoeh.antennapod.ui.share.ShareUtils;
 import de.danoeh.antennapod.ui.episodeslist.MoreContentListFooterUtil;
@@ -73,7 +73,6 @@ import de.danoeh.antennapod.model.download.DownloadResult;
 import de.danoeh.antennapod.model.feed.Feed;
 import de.danoeh.antennapod.model.feed.FeedItem;
 import de.danoeh.antennapod.model.feed.FeedItemFilter;
-import de.danoeh.antennapod.model.feed.SortOrder;
 import de.danoeh.antennapod.storage.preferences.UserPreferences;
 import de.danoeh.antennapod.ui.glide.FastBlurTransformation;
 import de.danoeh.antennapod.ui.episodeslist.EpisodeItemViewHolder;
@@ -91,6 +90,10 @@ public class FeedItemlistFragment extends Fragment implements AdapterView.OnItem
     public static final String TAG = "ItemlistFragment";
     private static final String ARGUMENT_FEED_ID = "argument.de.danoeh.antennapod.feed_id";
     private static final String KEY_UP_ARROW = "up_arrow";
+    protected static final int EPISODES_PER_PAGE = 150;
+    protected int page = 1;
+    protected boolean isLoadingMore = false;
+    protected boolean hasMoreItems = false;
 
     private FeedItemListAdapter adapter;
     private SwipeActions swipeActions;
@@ -147,6 +150,7 @@ public class FeedItemlistFragment extends Fragment implements AdapterView.OnItem
         }
         ((MainActivity) getActivity()).setupToolbarToggle(viewBinding.toolbar, displayUpArrow);
         updateToolbar();
+        setupLoadMoreScrollListener();
 
         viewBinding.recyclerView.setRecycledViewPool(((MainActivity) getActivity()).getRecycledViewPool());
         adapter = new FeedItemListAdapter((MainActivity) getActivity());
@@ -317,6 +321,21 @@ public class FeedItemlistFragment extends Fragment implements AdapterView.OnItem
         return FeedItemMenuHandler.onMenuItemClicked(this, item.getItemId(), selectedItem);
     }
 
+    private void setupLoadMoreScrollListener() {
+        viewBinding.recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
+            @Override
+            public void onScrolled(@NonNull RecyclerView view, int deltaX, int deltaY) {
+                super.onScrolled(view, deltaX, deltaY);
+                if (!isLoadingMore && hasMoreItems && viewBinding.recyclerView.isScrolledToBottom()) {
+                    /* The end of the list has been reached. Load more data. */
+                    page++;
+                    loadMoreItems();
+                    isLoadingMore = true;
+                }
+            }
+        });
+    }
+
     @Override
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
         MainActivity activity = (MainActivity) getActivity();
@@ -535,17 +554,23 @@ public class FeedItemlistFragment extends Fragment implements AdapterView.OnItem
         if (disposable != null) {
             disposable.dispose();
         }
-        disposable = Observable.fromCallable(this::loadData)
+        disposable = Observable.fromCallable(
+                () -> {
+                    feed = DBReader.getFeed(feedID, true, 0, page * EPISODES_PER_PAGE);
+                    int count = DBReader.getFeedEpisodeCount(feed.getId(), feed.getItemFilter());
+                    return new Pair<>(feed, count);
+                })
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(
                     result -> {
-                        feed = result;
+                        hasMoreItems = !(page == 1 && feed.getItems().size() < EPISODES_PER_PAGE);
                         swipeActions.setFilter(feed.getItemFilter());
                         refreshHeaderView();
                         viewBinding.progressBar.setVisibility(View.GONE);
                         adapter.setDummyViews(0);
                         adapter.updateItems(feed.getItems());
+                        adapter.setTotalNumberOfItems(result.second);
                         updateToolbar();
                     }, error -> {
                         feed = null;
@@ -557,19 +582,37 @@ public class FeedItemlistFragment extends Fragment implements AdapterView.OnItem
                     });
     }
 
-    @Nullable
+    private void loadMoreItems() {
-    private Feed loadData() {
+        if (disposable != null) {
-        Feed feed = DBReader.getFeed(feedID, true);
+            disposable.dispose();
-        if (feed == null) {
-            return null;
         }
-        DBReader.loadAdditionalFeedItemListData(feed.getItems());
+        isLoadingMore = true;
-        if (feed.getSortOrder() != null) {
+        adapter.setDummyViews(1);
-            List<FeedItem> feedItems = feed.getItems();
+        adapter.notifyItemInserted(adapter.getItemCount() - 1);
-            FeedItemPermutors.getPermutor(feed.getSortOrder()).reorder(feedItems);
+        disposable = Observable.fromCallable(() -> DBReader.getFeed(feedID, true,
-            feed.setItems(feedItems);
+                        (page - 1) * EPISODES_PER_PAGE, EPISODES_PER_PAGE))
-        }
+                .subscribeOn(Schedulers.io())
-        return feed;
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(
+                        data -> {
+                            if (data.getItems().size() < EPISODES_PER_PAGE) {
+                                hasMoreItems = false;
+                            }
+                            feed.getItems().addAll(data.getItems());
+                            adapter.setDummyViews(0);
+                            adapter.updateItems(feed.getItems());
+                            if (adapter.shouldSelectLazyLoadedItems()) {
+                                adapter.setSelected(feed.getItems().size() - data.getItems().size(),
+                                        feed.getItems().size(), true);
+                            }
+                        }, error -> {
+                            adapter.setDummyViews(0);
+                            adapter.updateItems(Collections.emptyList());
+                            Log.e(TAG, Log.getStackTraceString(error));
+                        }, () -> {
+                            // Make sure to not always load 2 pages at once
+                            viewBinding.recyclerView.post(() -> isLoadingMore = false);
+                        });
     }
 
     @Subscribe(threadMode = ThreadMode.MAIN)
@@ -608,45 +651,4 @@ public class FeedItemlistFragment extends Fragment implements AdapterView.OnItem
             MenuItemUtils.setOnClickListeners(menu, FeedItemlistFragment.this::onContextItemSelected);
         }
     }
-
-    public static class SingleFeedSortDialog extends ItemSortDialog {
-        private static final String ARG_FEED_ID = "feedId";
-        private static final String ARG_FEED_IS_LOCAL = "isLocal";
-        private static final String ARG_SORT_ORDER = "sortOrder";
-
-        private static SingleFeedSortDialog newInstance(Feed feed) {
-            Bundle bundle = new Bundle();
-            bundle.putLong(ARG_FEED_ID, feed.getId());
-            bundle.putBoolean(ARG_FEED_IS_LOCAL, feed.isLocalFeed());
-            if (feed.getSortOrder() == null) {
-                bundle.putString(ARG_SORT_ORDER, String.valueOf(SortOrder.DATE_NEW_OLD.code));
-            } else {
-                bundle.putString(ARG_SORT_ORDER, String.valueOf(feed.getSortOrder().code));
-            }
-            SingleFeedSortDialog dialog = new SingleFeedSortDialog();
-            dialog.setArguments(bundle);
-            return dialog;
-        }
-
-        @Override
-        public void onCreate(@Nullable Bundle savedInstanceState) {
-            super.onCreate(savedInstanceState);
-            sortOrder = SortOrder.fromCodeString(getArguments().getString(ARG_SORT_ORDER));
-        }
-
-        @Override
-        protected void onAddItem(int title, SortOrder ascending, SortOrder descending, boolean ascendingIsDefault) {
-            if (ascending == SortOrder.DATE_OLD_NEW || ascending == SortOrder.DURATION_SHORT_LONG
-                    || ascending == SortOrder.EPISODE_TITLE_A_Z
-                    || (getArguments().getBoolean(ARG_FEED_IS_LOCAL) && ascending == SortOrder.EPISODE_FILENAME_A_Z)) {
-                super.onAddItem(title, ascending, descending, ascendingIsDefault);
-            }
-        }
-
-        @Override
-        protected void onSelectionChanged() {
-            super.onSelectionChanged();
-            DBWriter.setFeedItemSortOrder(getArguments().getLong(ARG_FEED_ID), sortOrder);
-        }
-    }
 }

app/src/main/java/de/danoeh/antennapod/ui/screen/feed/SingleFeedSortDialog.java

@@ -0,0 +1,48 @@
+package de.danoeh.antennapod.ui.screen.feed;
+
+import android.os.Bundle;
+import androidx.annotation.Nullable;
+import de.danoeh.antennapod.model.feed.Feed;
+import de.danoeh.antennapod.model.feed.SortOrder;
+import de.danoeh.antennapod.storage.database.DBWriter;
+
+public class SingleFeedSortDialog extends ItemSortDialog {
+    private static final String ARG_FEED_ID = "feedId";
+    private static final String ARG_FEED_IS_LOCAL = "isLocal";
+    private static final String ARG_SORT_ORDER = "sortOrder";
+
+    public static SingleFeedSortDialog newInstance(Feed feed) {
+        Bundle bundle = new Bundle();
+        bundle.putLong(ARG_FEED_ID, feed.getId());
+        bundle.putBoolean(ARG_FEED_IS_LOCAL, feed.isLocalFeed());
+        if (feed.getSortOrder() == null) {
+            bundle.putString(ARG_SORT_ORDER, String.valueOf(SortOrder.DATE_NEW_OLD.code));
+        } else {
+            bundle.putString(ARG_SORT_ORDER, String.valueOf(feed.getSortOrder().code));
+        }
+        SingleFeedSortDialog dialog = new SingleFeedSortDialog();
+        dialog.setArguments(bundle);
+        return dialog;
+    }
+
+    @Override
+    public void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        sortOrder = SortOrder.fromCodeString(getArguments().getString(ARG_SORT_ORDER));
+    }
+
+    @Override
+    protected void onAddItem(int title, SortOrder ascending, SortOrder descending, boolean ascendingIsDefault) {
+        if (ascending == SortOrder.DATE_OLD_NEW || ascending == SortOrder.DURATION_SHORT_LONG
+                || ascending == SortOrder.EPISODE_TITLE_A_Z
+                || (getArguments().getBoolean(ARG_FEED_IS_LOCAL) && ascending == SortOrder.EPISODE_FILENAME_A_Z)) {
+            super.onAddItem(title, ascending, descending, ascendingIsDefault);
+        }
+    }
+
+    @Override
+    protected void onSelectionChanged() {
+        super.onSelectionChanged();
+        DBWriter.setFeedItemSortOrder(getArguments().getLong(ARG_FEED_ID), sortOrder);
+    }
+}

app/src/main/java/de/danoeh/antennapod/ui/screen/feed/preferences/FeedSettingsFragment.java

@@ -81,7 +81,7 @@ public class FeedSettingsFragment extends Fragment {
                 .commitAllowingStateLoss();
 
         disposable = Maybe.create((MaybeOnSubscribe<Feed>) emitter -> {
-            Feed feed = DBReader.getFeed(feedId);
+            Feed feed = DBReader.getFeed(feedId, false, 0, 0);
             if (feed != null) {
                 emitter.onSuccess(feed);
             } else {
@@ -163,7 +163,7 @@ public class FeedSettingsFragment extends Fragment {
 
             long feedId = getArguments().getLong(EXTRA_FEED_ID);
             disposable = Maybe.create((MaybeOnSubscribe<Feed>) emitter -> {
-                Feed feed = DBReader.getFeed(feedId);
+                Feed feed = DBReader.getFeed(feedId, false, 0, 0);
                 if (feed != null) {
                     emitter.onSuccess(feed);
                 } else {

app/src/main/java/de/danoeh/antennapod/ui/screen/onlinefeedview/OnlineFeedViewActivity.java

@@ -526,7 +526,7 @@ public class OnlineFeedViewActivity extends AppCompatActivity {
             if (didPressSubscribe) {
                 didPressSubscribe = false;
 
-                Feed feed1 = DBReader.getFeed(getFeedId());
+                Feed feed1 = DBReader.getFeed(getFeedId(), false, 0, 0);
                 FeedPreferences feedPreferences = feed1.getPreferences();
                 if (UserPreferences.isEnableAutodownload()) {
                     boolean autoDownload = viewBinding.autoDownloadCheckBox.isChecked();

net/download/service/src/main/java/de/danoeh/antennapod/net/download/service/feed/FeedUpdateWorker.java

@@ -76,7 +76,7 @@ public class FeedUpdateWorker extends Worker {
             }
             Collections.shuffle(toUpdate); // If the worker gets cancelled early, every feed has a chance to be updated
         } else {
-            Feed feed = DBReader.getFeed(feedId);
+            Feed feed = DBReader.getFeed(feedId, false, 0, Integer.MAX_VALUE);
             if (feed == null) {
                 return Result.success();
             }

net/download/service/src/test/java/de/danoeh/antennapod/net/download/service/episode/autodownload/DbReaderTest.java

@@ -154,7 +154,7 @@ public class DbReaderTest {
             List<FeedItem> items = feed.getItems();
             feed.setItems(null);
             List<FeedItem> savedItems = DBReader.getFeedItemList(feed,
-                    FeedItemFilter.unfiltered(), SortOrder.DATE_NEW_OLD);
+                    FeedItemFilter.unfiltered(), SortOrder.DATE_NEW_OLD, 0, Integer.MAX_VALUE);
             assertNotNull(savedItems);
             assertEquals(items.size(), savedItems.size());
             for (int i = 0; i < savedItems.size(); i++) {

net/download/service/src/test/java/de/danoeh/antennapod/net/download/service/episode/autodownload/DbTasksTest.java

@@ -133,7 +133,7 @@ public class DbTasksTest {
 
         updatedFeedTest(newFeed, feedID, itemIDs, numItemsOld, numItemsNew);
 
-        final Feed feedFromDB = DBReader.getFeed(newFeed.getId());
+        final Feed feedFromDB = DBReader.getFeed(newFeed.getId(), false, 0, Integer.MAX_VALUE);
         assertNotNull(feedFromDB);
         assertEquals(newFeed.getId(), feedFromDB.getId());
         updatedFeedTest(feedFromDB, feedID, itemIDs, numItemsOld, numItemsNew);
@@ -163,7 +163,7 @@ public class DbTasksTest {
         final Feed newFeed = FeedDatabaseWriter.updateFeed(context, feed, false);
         assertNotSame(newFeed, feed);
 
-        final Feed feedFromDB = DBReader.getFeed(newFeed.getId());
+        final Feed feedFromDB = DBReader.getFeed(newFeed.getId(), false, 0, Integer.MAX_VALUE);
         final FeedItem feedItemFromDB = feedFromDB.getItems().get(0);
         assertTrue(feedItemFromDB.isNew());
     }
@@ -186,7 +186,7 @@ public class DbTasksTest {
         Feed newFeed = FeedDatabaseWriter.updateFeed(context, feed, true);
         assertEquals(8, newFeed.getItems().size()); // 10 - 2 = 8 items
 
-        Feed feedFromDB = DBReader.getFeed(newFeed.getId());
+        Feed feedFromDB = DBReader.getFeed(newFeed.getId(), false, 0, Integer.MAX_VALUE);
         assertEquals(8, feedFromDB.getItems().size()); // 10 - 2 = 8 items
     }
 
@@ -213,7 +213,7 @@ public class DbTasksTest {
         Feed newFeed = FeedDatabaseWriter.updateFeed(context, feed, false);
         assertEquals(10, newFeed.getItems().size()); // id 1-duplicate replaces because the stream url is the same
 
-        Feed feedFromDB = DBReader.getFeed(newFeed.getId());
+        Feed feedFromDB = DBReader.getFeed(newFeed.getId(), false, 0, Integer.MAX_VALUE);
         assertEquals(10, feedFromDB.getItems().size()); // id1-duplicate should override id 1
 
         FeedItem updatedItem = feedFromDB.getItemAtIndex(9);

net/download/service/src/test/java/de/danoeh/antennapod/net/download/service/episode/autodownload/DbWriterTest.java

@@ -771,7 +771,7 @@ public class DbWriterTest {
 
         DBWriter.removeAllNewFlags().get();
         List<FeedItem> loadedItems = DBReader.getFeedItemList(feed,
-                FeedItemFilter.unfiltered(), SortOrder.DATE_NEW_OLD);
+                FeedItemFilter.unfiltered(), SortOrder.DATE_NEW_OLD, 0, Integer.MAX_VALUE);
         for (FeedItem item : loadedItems) {
             assertFalse(item.isNew());
         }

net/download/service/src/test/java/de/danoeh/antennapod/net/download/service/feed/local/LocalFeedUpdaterTest.java

@@ -169,7 +169,8 @@ public class LocalFeedUpdaterTest {
         callUpdateFeed(LOCAL_FEED_DIR1);
 
         Feed feed = verifySingleFeedInDatabase();
-        List<FeedItem> feedItems = DBReader.getFeedItemList(feed, FeedItemFilter.unfiltered(), SortOrder.DATE_NEW_OLD);
+        List<FeedItem> feedItems = DBReader.getFeedItemList(feed, FeedItemFilter.unfiltered(),
+                SortOrder.DATE_NEW_OLD, 0, Integer.MAX_VALUE);
         assertEquals("track1.mp3", feedItems.get(0).getTitle());
     }
 
@@ -283,7 +284,8 @@ public class LocalFeedUpdaterTest {
      */
     private static void verifySingleFeedInDatabaseAndItemCount(int expectedItemCount) {
         Feed feed = verifySingleFeedInDatabase();
-        List<FeedItem> feedItems = DBReader.getFeedItemList(feed, FeedItemFilter.unfiltered(), SortOrder.DATE_NEW_OLD);
+        List<FeedItem> feedItems = DBReader.getFeedItemList(feed, FeedItemFilter.unfiltered(),
+                SortOrder.DATE_NEW_OLD, 0, Integer.MAX_VALUE);
         assertEquals(expectedItemCount, feedItems.size());
     }
 

playback/service/src/main/java/de/danoeh/antennapod/playback/service/PlaybackService.java

@@ -94,7 +94,6 @@ import de.danoeh.antennapod.model.feed.FeedItem;
 import de.danoeh.antennapod.model.feed.FeedItemFilter;
 import de.danoeh.antennapod.model.feed.FeedMedia;
 import de.danoeh.antennapod.model.feed.FeedPreferences;
-import de.danoeh.antennapod.model.feed.SortOrder;
 import de.danoeh.antennapod.model.playback.MediaType;
 import de.danoeh.antennapod.model.playback.Playable;
 import de.danoeh.antennapod.playback.base.PlaybackServiceMediaPlayer;
@@ -452,12 +451,7 @@ public class PlaybackService extends MediaBrowserServiceCompat {
                     new FeedItemFilter(FeedItemFilter.UNPLAYED), UserPreferences.getAllEpisodesSortOrder());
         } else if (parentId.startsWith("FeedId:")) {
             long feedId = Long.parseLong(parentId.split(":")[1]);
-            Feed feed = DBReader.getFeed(feedId);
+            feedItems = DBReader.getFeed(feedId, true, 0, MAX_ANDROID_AUTO_EPISODES_PER_FEED).getItems();
-            SortOrder sortOrder = feed.getSortOrder();
-            if (sortOrder == null) {
-                sortOrder = SortOrder.DATE_NEW_OLD;
-            }
-            feedItems = DBReader.getFeedItemList(feed, FeedItemFilter.unfiltered(), sortOrder);
         } else if (parentId.equals(getString(R.string.current_playing_episode))) {
             FeedMedia playable = DBReader.getFeedMedia(PlaybackPreferences.getCurrentlyPlayingFeedMediaId());
             if (playable != null) {

storage/database/src/main/java/de/danoeh/antennapod/storage/database/DBReader.java

@@ -149,12 +149,14 @@ public final class DBReader {
      * @param feed The Feed whose items should be loaded
      * @return A list with the FeedItems of the Feed. The Feed-attribute of the FeedItems will already be set correctly.
      */
-    public static List<FeedItem> getFeedItemList(final Feed feed, final FeedItemFilter filter, SortOrder sortOrder) {
+    public static List<FeedItem> getFeedItemList(final Feed feed, final FeedItemFilter filter, SortOrder sortOrder,
+                                                 int offset, int limit) {
         Log.d(TAG, "getFeedItemList() called with: " + "feed = [" + feed + "]");
 
         PodDBAdapter adapter = PodDBAdapter.getInstance();
         adapter.open();
-        try (FeedItemCursor cursor = new FeedItemCursor(adapter.getItemsOfFeedCursor(feed, filter, sortOrder))) {
+        try (FeedItemCursor cursor = new FeedItemCursor(adapter.getItemsOfFeedCursor(
+                feed, filter, sortOrder, offset, limit))) {
             List<FeedItem> items = extractItemlistFromCursor(cursor);
             feed.setItems(items);
             for (FeedItem item : items) {
@@ -266,6 +268,19 @@ public final class DBReader {
         }
     }
 
+    public static int getFeedEpisodeCount(long feedId, FeedItemFilter filter) {
+        PodDBAdapter adapter = PodDBAdapter.getInstance();
+        adapter.open();
+        try (Cursor cursor = adapter.getFeedEpisodeCountCursor(feedId, filter)) {
+            if (cursor.moveToFirst()) {
+                return cursor.getInt(0);
+            }
+            return -1;
+        } finally {
+            adapter.close();
+        }
+    }
+
     public static List<FeedItem> getRandomEpisodes(int limit, int seed) {
         PodDBAdapter adapter = PodDBAdapter.getInstance();
         adapter.open();
@@ -324,18 +339,6 @@ public final class DBReader {
         }
     }
 
-    /**
-     * Loads a specific Feed from the database.
-     *
-     * @param feedId The ID of the Feed
-     * @return The Feed or null if the Feed could not be found. The Feeds FeedItems will also be loaded from the
-     *         database and the items-attribute will be set correctly.
-     */
-    @Nullable
-    public static Feed getFeed(final long feedId) {
-        return getFeed(feedId, false);
-    }
-
     /**
      * Loads a specific Feed from the database.
      *
@@ -345,7 +348,7 @@ public final class DBReader {
      *         database and the items-attribute will be set correctly.
      */
     @Nullable
-    public static Feed getFeed(final long feedId, boolean filtered) {
+    public static Feed getFeed(final long feedId, boolean filtered, int offset, int limit) {
         Log.d(TAG, "getFeed() called with: " + "feedId = [" + feedId + "]");
         PodDBAdapter adapter = PodDBAdapter.getInstance();
         adapter.open();
@@ -354,7 +357,12 @@ public final class DBReader {
             if (cursor.moveToNext()) {
                 feed = cursor.getFeed();
                 FeedItemFilter filter = filtered ? feed.getItemFilter() : FeedItemFilter.unfiltered();
-                feed.setItems(getFeedItemList(feed, filter, feed.getSortOrder()));
+                List<FeedItem> items = getFeedItemList(feed, filter, feed.getSortOrder(), offset, limit);
+                for (FeedItem item : items) {
+                    item.setFeed(feed);
+                }
+                loadTagsOfFeedItemList(items);
+                feed.setItems(items);
             } else {
                 Log.e(TAG, "getFeed could not find feed with id " + feedId);
             }

storage/database/src/main/java/de/danoeh/antennapod/storage/database/DBWriter.java

@@ -161,7 +161,7 @@ public class DBWriter {
      */
     public static Future<?> deleteFeed(final Context context, final long feedId) {
         return runOnDbThread(() -> {
-            final Feed feed = DBReader.getFeed(feedId, false);
+            final Feed feed = DBReader.getFeed(feedId, false, 0, Integer.MAX_VALUE);
             if (feed == null) {
                 return;
             }

storage/database/src/main/java/de/danoeh/antennapod/storage/database/FeedDatabaseWriter.java

@@ -31,12 +31,13 @@ public abstract class FeedDatabaseWriter {
 
     private static Feed searchFeedByIdentifyingValueOrID(Feed feed) {
         if (feed.getId() != 0) {
-            return DBReader.getFeed(feed.getId());
+            return DBReader.getFeed(feed.getId(), false, 0, Integer.MAX_VALUE);
         } else {
             List<Feed> feeds = DBReader.getFeedList();
             for (Feed f : feeds) {
                 if (f.getIdentifyingValue().equals(feed.getIdentifyingValue())) {
-                    f.setItems(DBReader.getFeedItemList(f, FeedItemFilter.unfiltered(), SortOrder.DATE_NEW_OLD));
+                    f.setItems(DBReader.getFeedItemList(f, FeedItemFilter.unfiltered(),
+                            SortOrder.DATE_NEW_OLD, 0, Integer.MAX_VALUE));
                     return f;
                 }
             }

storage/database/src/main/java/de/danoeh/antennapod/storage/database/PodDBAdapter.java

@@ -954,14 +954,16 @@ public class PodDBAdapter {
      * @param feed The feed you want to get the FeedItems from.
      * @return The cursor of the query
      */
-    public final Cursor getItemsOfFeedCursor(final Feed feed, FeedItemFilter filter, SortOrder sortOrder) {
+    public final Cursor getItemsOfFeedCursor(final Feed feed, FeedItemFilter filter, SortOrder sortOrder,
+                                             int offset, int limit) {
         String orderByQuery = FeedItemSortQuery.generateFrom(sortOrder);
         String filterQuery = FeedItemFilterQuery.generateFrom(filter);
         String whereClauseAnd = "".equals(filterQuery) ? "" : " AND " + filterQuery;
         final String query = SELECT_FEED_ITEMS_AND_MEDIA
                 + " WHERE " + TABLE_NAME_FEED_ITEMS + "." + KEY_FEED + "=" + feed.getId()
                 + whereClauseAnd
-                + " ORDER BY " + orderByQuery;
+                + " ORDER BY " + orderByQuery
+                + " LIMIT " + offset + ", " + limit;
         return db.rawQuery(query, null);
     }
 
@@ -1082,6 +1084,15 @@ public class PodDBAdapter {
         return db.rawQuery(query, null);
     }
 
+    public final Cursor getFeedEpisodeCountCursor(long feedId, FeedItemFilter filter) {
+        String filterQuery = FeedItemFilterQuery.generateFrom(filter);
+        String whereAndClause = "".equals(filterQuery) ? "" : " AND " + filterQuery;
+        final String query = "SELECT count(" + TABLE_NAME_FEED_ITEMS + "." + KEY_ID + ") FROM " + TABLE_NAME_FEED_ITEMS
+                + JOIN_FEED_ITEM_AND_MEDIA
+                + " WHERE " + TABLE_NAME_FEED_ITEMS + "." + KEY_FEED + "=" + feedId + whereAndClause;
+        return db.rawQuery(query, null);
+    }
+
     public Cursor getRandomEpisodesCursor(int limit, int seed) {
         final String allItemsRandomOrder = SELECT_FEED_ITEMS_AND_MEDIA
                 + " WHERE (" + KEY_READ + " = " + FeedItem.NEW + " OR " + KEY_READ + " = " + FeedItem.UNPLAYED + ") "

ui/statistics/src/main/java/de/danoeh/antennapod/ui/statistics/feed/FeedStatisticsFragment.java

@@ -78,7 +78,7 @@ public class FeedStatisticsFragment extends Fragment {
                     for (StatisticsItem statisticsItem : statisticsData.feedTime) {
                         if (statisticsItem.feed.getId() == feedId) {
                             List<FeedItem> items = DBReader.getFeedItemList(statisticsItem.feed,
-                                    FeedItemFilter.unfiltered(), SortOrder.DATE_OLD_NEW);
+                                    FeedItemFilter.unfiltered(), SortOrder.DATE_OLD_NEW, 0, Integer.MAX_VALUE);
                             List<Date> dates = new ArrayList<>();
                             for (FeedItem item : items) {
                                 dates.add(item.getPubDate());