Fixed the functionality, improved performance & general code cleanup

app/src/main/java/org/schabi/newpipe/database/playlist/dao/PlaylistStreamDAO.java

@@ -57,7 +57,7 @@ public interface PlaylistStreamDAO extends BasicDAO<PlaylistStreamEntity> {
             + " WHERE " + JOIN_PLAYLIST_ID + " = :playlistId "
             + " AND " + STREAM_URL + " = :streamURL"
     )
-    Flowable<Integer> getDuplicates(long playlistId, String streamURL);
+    Flowable<Integer> getDuplicateCount(long playlistId, String streamURL);
 
     @Query("SELECT " + JOIN_PLAYLIST_ID
             + " FROM " + STREAM_TABLE
@@ -67,7 +67,6 @@ public interface PlaylistStreamDAO extends BasicDAO<PlaylistStreamEntity> {
     )
     Flowable<List<Long>> getDuplicatePlaylists(String streamURL);
 
-
     @Query("SELECT COALESCE(MAX(" + JOIN_INDEX + "), -1)"
             + " FROM " + PLAYLIST_STREAM_JOIN_TABLE
             + " WHERE " + JOIN_PLAYLIST_ID + " = :playlistId")

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

@@ -16,7 +16,6 @@ import org.schabi.newpipe.NewPipeDatabase;
 import org.schabi.newpipe.R;
 import org.schabi.newpipe.database.playlist.PlaylistMetadataEntry;
 import org.schabi.newpipe.database.stream.model.StreamEntity;
-import org.schabi.newpipe.fragments.OnScrollBelowItemsListener;
 import org.schabi.newpipe.local.LocalItemListAdapter;
 import org.schabi.newpipe.local.playlist.LocalPlaylistManager;
 
@@ -28,8 +27,12 @@ import io.reactivex.rxjava3.disposables.CompositeDisposable;
 public final class PlaylistAppendDialog extends PlaylistDialog {
     private static final String TAG = PlaylistAppendDialog.class.getCanonicalName();
 
+    private static final float DEFAULT_ALPHA = 1f;
+    private static final float GRAYED_OUT_ALPHA = 0.3f;
+
     private RecyclerView playlistRecyclerView;
     private LocalItemListAdapter playlistAdapter;
+    private List<Long> duplicateIds;
 
     private final CompositeDisposable playlistDisposables = new CompositeDisposable();
 
@@ -62,6 +65,9 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
         final LocalPlaylistManager playlistManager =
                 new LocalPlaylistManager(NewPipeDatabase.getInstance(requireContext()));
 
+        duplicateIds = playlistManager.getDuplicatePlaylists(getStreamEntities().get(0).getUrl())
+                .blockingFirst();
+
         playlistAdapter = new LocalItemListAdapter(getActivity());
         playlistAdapter.setHasStableIds(true);
         playlistAdapter.setSelectedListener(selectedItem -> {
@@ -126,43 +132,43 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
             playlistAdapter.addItems(playlists);
             playlistRecyclerView.setVisibility(View.VISIBLE);
 
-            playlistRecyclerView.addOnScrollListener(new DefaultItemListOnScrolledDownListener());
+            playlistRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
+                @Override
+                public void onScrolled(@NonNull final RecyclerView recyclerView, final int dx,
+                                       final int dy) {
+                    showDuplicateIndicators(recyclerView);
+                }
+            });
             initDuplicateIndicators(playlistRecyclerView);
         }
     }
 
-    public class DefaultItemListOnScrolledDownListener extends OnScrollBelowItemsListener {
-        @Override
-        public void onScrolledDown(final RecyclerView recyclerView) {
-            showDuplicateIndicators(recyclerView);
-        }
-    }
-
     public void initDuplicateIndicators(@NonNull final RecyclerView view) {
-        view.postDelayed(new Runnable() {
-            @Override
-            public void run() {
         showDuplicateIndicators(view);
+
+        if (!duplicateIds.isEmpty()) {
+            final View indicatorExplanation = getView()
+                    .findViewById(R.id.playlist_duplicate);
+            indicatorExplanation.setVisibility(View.VISIBLE);
         }
-        }, 50);
     }
 
-    public void showDuplicateIndicators(final RecyclerView view) {
+    public void showDuplicateIndicators(@NonNull final RecyclerView view) {
-        final LocalPlaylistManager playlistManager =
-                new LocalPlaylistManager(NewPipeDatabase.getInstance(requireContext()));
-        final List<Long> duplicateIds = playlistManager.getDuplicatePlaylist(getStreamEntities()
-                .get(0).getUrl()).blockingFirst();
-
         if (view.getAdapter() == null) {
             return;
         }
 
         final int count = view.getAdapter().getItemCount();
         for (int i = 0; i < count; i++) {
-            if (view.findViewHolderForAdapterPosition(i) != null
+
-                    && duplicateIds.contains(playlistAdapter.getItemId(i))) {
+            final RecyclerView.ViewHolder viewHolder = view.findViewHolderForAdapterPosition(i);
-                view.findViewHolderForAdapterPosition(i).itemView
+            if (viewHolder != null) {
-                        .findViewById(R.id.checkmark2).setVisibility(View.VISIBLE);
+                if (duplicateIds.contains(view.getAdapter().getItemId(i))) {
+                    viewHolder.itemView.setAlpha(GRAYED_OUT_ALPHA);
+                } else {
+                    viewHolder.itemView.setAlpha(DEFAULT_ALPHA);
+                }
+
             }
         }
     }
@@ -171,10 +177,10 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
                                     @NonNull final PlaylistMetadataEntry playlist,
                                     @NonNull final List<StreamEntity> streams) {
 
-        final int numOfDuplicates = manager.getPlaylistDuplicates(playlist.uid,
+        final int numberOfDuplicates = manager.getPlaylistDuplicateCount(playlist.uid,
                         streams.get(0).getUrl()).blockingFirst();
-        if (numOfDuplicates > 0) {
+        if (numberOfDuplicates > 0) {
-            createDuplicateDialog(numOfDuplicates, manager, playlist, streams);
+            createDuplicateDialog(numberOfDuplicates, manager, playlist, streams);
         } else {
             addStreamToPlaylist(manager, playlist, streams);
         }
@@ -197,22 +203,24 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
         playlistDisposables.add(manager.appendToPlaylist(playlist.uid, streams)
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(ignored -> successToast.show()));
+
         requireDialog().dismiss();
     }
 
-    private void createDuplicateDialog(final int duplicates,
+    private void createDuplicateDialog(final int numberOfDuplicates,
                                        @NonNull final LocalPlaylistManager manager,
                                        @NonNull final PlaylistMetadataEntry playlist,
                                        @NonNull final List<StreamEntity> streams) {
         final AlertDialog.Builder builder = new AlertDialog.Builder(this.getActivity());
         builder.setTitle(R.string.duplicate_stream_in_playlist_title);
         builder.setMessage(getString(R.string.duplicate_stream_in_playlist_description,
-                duplicates));
+                numberOfDuplicates));
 
         builder.setPositiveButton(android.R.string.yes, (dialog, i) -> {
             addStreamToPlaylist(manager, playlist, streams);
         });
         builder.setNeutralButton(R.string.cancel, null);
+
         builder.create().show();
     }
 }

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

@@ -91,11 +91,12 @@ public class LocalPlaylistManager {
         return playlistStreamTable.getOrderedStreamsOf(playlistId).subscribeOn(Schedulers.io());
     }
 
-    public Flowable<Integer> getPlaylistDuplicates(final long playlistId, final String streamURL) {
+    public Flowable<Integer> getPlaylistDuplicateCount(final long playlistId,
-        return playlistStreamTable.getDuplicates(playlistId, streamURL);
+                                                       final String streamURL) {
+        return playlistStreamTable.getDuplicateCount(playlistId, streamURL);
     }
 
-    public Flowable<List<Long>> getDuplicatePlaylist(final String streamURL) {
+    public Flowable<List<Long>> getDuplicatePlaylists(final String streamURL) {
         return playlistStreamTable.getDuplicatePlaylists(streamURL);
     }
 

app/src/main/res/layout/dialog_playlists.xml

@@ -34,11 +34,26 @@
             tools:ignore="RtlHardcoded" />
     </RelativeLayout>
 
+    <org.schabi.newpipe.views.NewPipeTextView
+        android:id="@+id/playlist_duplicate"
+        android:layout_width="match_parent"
+        android:layout_height="40dp"
+        android:layout_below="@+id/newPlaylist"
+        android:text="@string/duplicate_in_playlist"
+        android:textAppearance="?android:attr/textAppearanceLarge"
+        android:textSize="15sp"
+        android:layout_marginStart="10dp"
+        android:layout_marginEnd="10dp"
+        android:inputType="textMultiLine"
+        android:layout_centerHorizontal="true"
+        android:layout_marginBottom="@dimen/video_item_search_padding"
+        android:visibility="gone" />
+
     <View
         android:id="@+id/separator"
         android:layout_width="match_parent"
         android:layout_height="1dp"
-        android:layout_below="@+id/newPlaylist"
+        android:layout_below="@+id/playlist_duplicate"
         android:layout_marginLeft="@dimen/video_item_search_padding"
         android:layout_marginRight="@dimen/video_item_search_padding"
         android:background="?attr/separator_color" />

app/src/main/res/layout/list_playlist_mini_item.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/itemRoot"
     android:layout_width="match_parent"
@@ -22,17 +21,6 @@
         android:src="@drawable/placeholder_thumbnail_playlist"
         tools:ignore="RtlHardcoded" />
 
-
-    <ImageView
-        android:id="@+id/checkmark2"
-        android:layout_width="20dp"
-        android:layout_height="20dp"
-        android:layout_alignBottom="@id/itemThumbnailView"
-        android:layout_marginBottom="-1dp"
-        android:src="@drawable/ic_done"
-        android:visibility="gone"
-        app:tint="#E81111" />
-
     <org.schabi.newpipe.views.NewPipeTextView
         android:id="@+id/itemStreamCountView"
         android:layout_width="45dp"

app/src/main/res/values/strings.xml

@@ -432,6 +432,7 @@
     <string name="preferred_player_fetcher_notification_message">"Loading requested content"</string>
     <!-- Local Playlist -->
     <string name="create_playlist">New Playlist</string>
+    <string name="duplicate_in_playlist">The playlists that are grayed out already contain this item.</string>
     <string name="rename_playlist">Rename</string>
     <string name="name">Name</string>
     <string name="add_to_playlist">Add to playlist</string>