Make OnClickGesture an interface.

app/src/main/java/org/schabi/newpipe/fragments/list/BaseListFragment.java

@@ -23,14 +23,11 @@ import androidx.recyclerview.widget.RecyclerView;
 import org.schabi.newpipe.R;
 import org.schabi.newpipe.error.ErrorUtil;
 import org.schabi.newpipe.extractor.InfoItem;
-import org.schabi.newpipe.extractor.channel.ChannelInfoItem;
-import org.schabi.newpipe.extractor.comments.CommentsInfoItem;
-import org.schabi.newpipe.extractor.playlist.PlaylistInfoItem;
 import org.schabi.newpipe.extractor.stream.StreamInfoItem;
 import org.schabi.newpipe.fragments.BaseStateFragment;
 import org.schabi.newpipe.fragments.OnScrollBelowItemsListener;
-import org.schabi.newpipe.info_list.dialog.InfoItemDialog;
 import org.schabi.newpipe.info_list.InfoListAdapter;
+import org.schabi.newpipe.info_list.dialog.InfoItemDialog;
 import org.schabi.newpipe.util.NavigationHelper;
 import org.schabi.newpipe.util.OnClickGesture;
 import org.schabi.newpipe.util.StateSaver;
@@ -264,45 +261,28 @@ public abstract class BaseListFragment<I, N> extends BaseStateFragment<I>
             }
         });
 
-        infoListAdapter.setOnChannelSelectedListener(new OnClickGesture<>() {
-            @Override
-            public void selected(final ChannelInfoItem selectedItem) {
-                try {
-                    onItemSelected(selectedItem);
-                    NavigationHelper.openChannelFragment(getFM(),
-                            selectedItem.getServiceId(),
-                            selectedItem.getUrl(),
-                            selectedItem.getName());
-                } catch (final Exception e) {
-                    ErrorUtil.showUiErrorSnackbar(
-                            BaseListFragment.this, "Opening channel fragment", e);
-                }
-            }
-        });
-
-        infoListAdapter.setOnPlaylistSelectedListener(new OnClickGesture<>() {
-            @Override
-            public void selected(final PlaylistInfoItem selectedItem) {
-                try {
-                    onItemSelected(selectedItem);
-                    NavigationHelper.openPlaylistFragment(getFM(),
-                            selectedItem.getServiceId(),
-                            selectedItem.getUrl(),
-                            selectedItem.getName());
-                } catch (final Exception e) {
-                    ErrorUtil.showUiErrorSnackbar(BaseListFragment.this,
-                            "Opening playlist fragment", e);
-                }
-            }
-        });
-
-        infoListAdapter.setOnCommentsSelectedListener(new OnClickGesture<>() {
-            @Override
-            public void selected(final CommentsInfoItem selectedItem) {
+        infoListAdapter.setOnChannelSelectedListener(selectedItem -> {
+            try {
                 onItemSelected(selectedItem);
+                NavigationHelper.openChannelFragment(getFM(), selectedItem.getServiceId(),
+                        selectedItem.getUrl(), selectedItem.getName());
+            } catch (final Exception e) {
+                ErrorUtil.showUiErrorSnackbar(this, "Opening channel fragment", e);
             }
         });
 
+        infoListAdapter.setOnPlaylistSelectedListener(selectedItem -> {
+            try {
+                onItemSelected(selectedItem);
+                NavigationHelper.openPlaylistFragment(getFM(), selectedItem.getServiceId(),
+                        selectedItem.getUrl(), selectedItem.getName());
+            } catch (final Exception e) {
+                ErrorUtil.showUiErrorSnackbar(this, "Opening playlist fragment", e);
+            }
+        });
+
+        infoListAdapter.setOnCommentsSelectedListener(this::onItemSelected);
+
         // Ensure that there is always a scroll listener (e.g. when rotating the device)
         useNormalItemListScrollListener();
     }

app/src/main/java/org/schabi/newpipe/local/bookmark/BookmarkFragment.java

@@ -98,7 +98,7 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
     protected void initListeners() {
         super.initListeners();
 
-        itemListAdapter.setSelectedListener(new OnClickGesture<LocalItem>() {
+        itemListAdapter.setSelectedListener(new OnClickGesture<>() {
             @Override
             public void selected(final LocalItem selectedItem) {
                 final FragmentManager fragmentManager = getFM();

app/src/main/java/org/schabi/newpipe/local/dialog/PlaylistAppendDialog.java

@@ -13,12 +13,10 @@ import androidx.recyclerview.widget.RecyclerView;
 
 import org.schabi.newpipe.NewPipeDatabase;
 import org.schabi.newpipe.R;
-import org.schabi.newpipe.database.LocalItem;
 import org.schabi.newpipe.database.playlist.PlaylistMetadataEntry;
 import org.schabi.newpipe.database.stream.model.StreamEntity;
 import org.schabi.newpipe.local.LocalItemListAdapter;
 import org.schabi.newpipe.local.playlist.LocalPlaylistManager;
-import org.schabi.newpipe.util.OnClickGesture;
 
 import java.util.List;
 
@@ -63,18 +61,10 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
                 new LocalPlaylistManager(NewPipeDatabase.getInstance(requireContext()));
 
         playlistAdapter = new LocalItemListAdapter(getActivity());
-        playlistAdapter.setSelectedListener(new OnClickGesture<LocalItem>() {
-            @Override
-            public void selected(final LocalItem selectedItem) {
-                if (!(selectedItem instanceof PlaylistMetadataEntry)
-                        || getStreamEntities() == null) {
-                    return;
-                }
-                onPlaylistSelected(
-                        playlistManager,
-                        (PlaylistMetadataEntry) selectedItem,
-                        getStreamEntities()
-                );
+        playlistAdapter.setSelectedListener(selectedItem -> {
+            final List<StreamEntity> entities = getStreamEntities();
+            if (selectedItem instanceof PlaylistMetadataEntry && entities != null) {
+                onPlaylistSelected(playlistManager, (PlaylistMetadataEntry) selectedItem, entities);
             }
         });
 
@@ -138,10 +128,6 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
     private void onPlaylistSelected(@NonNull final LocalPlaylistManager manager,
                                     @NonNull final PlaylistMetadataEntry playlist,
                                     @NonNull final List<StreamEntity> streams) {
-        if (getStreamEntities() == null) {
-            return;
-        }
-
         final Toast successToast = Toast.makeText(getContext(),
                 R.string.playlist_add_stream_success, Toast.LENGTH_SHORT);
 

app/src/main/java/org/schabi/newpipe/local/history/StatisticsPlaylistFragment.java

@@ -135,7 +135,7 @@ public class StatisticsPlaylistFragment
     protected void initListeners() {
         super.initListeners();
 
-        itemListAdapter.setSelectedListener(new OnClickGesture<LocalItem>() {
+        itemListAdapter.setSelectedListener(new OnClickGesture<>() {
             @Override
             public void selected(final LocalItem selectedItem) {
                 if (selectedItem instanceof StreamStatisticsEntry) {

app/src/main/java/org/schabi/newpipe/local/playlist/LocalPlaylistFragment.java

@@ -167,7 +167,7 @@ public class LocalPlaylistFragment extends BaseLocalListFragment<List<PlaylistSt
         itemTouchHelper = new ItemTouchHelper(getItemTouchCallback());
         itemTouchHelper.attachToRecyclerView(itemsList);
 
-        itemListAdapter.setSelectedListener(new OnClickGesture<LocalItem>() {
+        itemListAdapter.setSelectedListener(new OnClickGesture<>() {
             @Override
             public void selected(final LocalItem selectedItem) {
                 if (selectedItem instanceof PlaylistStreamEntry) {

app/src/main/java/org/schabi/newpipe/local/subscription/SubscriptionFragment.kt

@@ -346,7 +346,7 @@ class SubscriptionFragment : BaseStateFragment<SubscriptionState>() {
     override fun doInitialLoadLogic() = Unit
     override fun startLoading(forceLoad: Boolean) = Unit
 
-    private val listenerFeedGroups = object : OnClickGesture<Item<*>>() {
+    private val listenerFeedGroups = object : OnClickGesture<Item<*>> {
         override fun selected(selectedItem: Item<*>?) {
             when (selectedItem) {
                 is FeedGroupCardItem -> NavigationHelper.openFeedFragment(fm, selectedItem.groupId, selectedItem.name)
@@ -361,7 +361,7 @@ class SubscriptionFragment : BaseStateFragment<SubscriptionState>() {
         }
     }
 
-    private val listenerChannelItem = object : OnClickGesture<ChannelInfoItem>() {
+    private val listenerChannelItem = object : OnClickGesture<ChannelInfoItem> {
         override fun selected(selectedItem: ChannelInfoItem) = NavigationHelper.openChannelFragment(
             fm,
             selectedItem.serviceId, selectedItem.url, selectedItem.name

app/src/main/java/org/schabi/newpipe/util/OnClickGesture.java

@@ -2,15 +2,14 @@ package org.schabi.newpipe.util;
 
 import androidx.recyclerview.widget.RecyclerView;
 
-public abstract class OnClickGesture<T> {
+public interface OnClickGesture<T> {
+    void selected(T selectedItem);
 
-    public abstract void selected(T selectedItem);
-
-    public void held(final T selectedItem) {
+    default void held(final T selectedItem) {
         // Optional gesture
     }
 
-    public void drag(final T selectedItem, final RecyclerView.ViewHolder viewHolder) {
+    default void drag(final T selectedItem, final RecyclerView.ViewHolder viewHolder) {
         // Optional gesture
     }
 }