fix: Prevent externalAudioReader from hogging the main thread

app/src/main/java/com/cappielloantonio/tempo/ui/adapter/SongHorizontalAdapter.java

@@ -11,6 +11,7 @@ import android.widget.Filterable;
 
 import androidx.annotation.NonNull;
 import androidx.appcompat.content.res.AppCompatResources;
+import androidx.lifecycle.LifecycleOwner;
 import androidx.media3.common.util.UnstableApi;
 import androidx.media3.session.MediaBrowser;
 import androidx.recyclerview.widget.RecyclerView;
@@ -25,6 +26,7 @@ import com.cappielloantonio.tempo.subsonic.models.DiscTitle;
 import com.cappielloantonio.tempo.util.Constants;
 import com.cappielloantonio.tempo.util.DownloadUtil;
 import com.cappielloantonio.tempo.util.ExternalAudioReader;
+import com.cappielloantonio.tempo.util.MappingUtil;
 import com.cappielloantonio.tempo.util.MusicUtil;
 import com.cappielloantonio.tempo.util.Preferences;
 import com.google.common.util.concurrent.ListenableFuture;
@@ -90,7 +92,7 @@ public class SongHorizontalAdapter extends RecyclerView.Adapter<SongHorizontalAd
         }
     };
 
-    public SongHorizontalAdapter(ClickCallback click, boolean showCoverArt, boolean showAlbum, AlbumID3 album) {
+    public SongHorizontalAdapter(LifecycleOwner lifecycleOwner, ClickCallback click, boolean showCoverArt, boolean showAlbum, AlbumID3 album) {
         this.click = click;
         this.showCoverArt = showCoverArt;
         this.showAlbum = showAlbum;
@@ -99,6 +101,10 @@ public class SongHorizontalAdapter extends RecyclerView.Adapter<SongHorizontalAd
         this.currentFilter = "";
         this.album = album;
         setHasStableIds(false);
+
+        if (lifecycleOwner != null) {
+            MappingUtil.observeExternalAudioRefresh(lifecycleOwner, this::handleExternalAudioRefresh);
+        }
     }
 
     @NonNull
@@ -204,6 +210,12 @@ public class SongHorizontalAdapter extends RecyclerView.Adapter<SongHorizontalAd
         bindPlaybackState(holder, song);
     }
 
+    private void handleExternalAudioRefresh() {
+        if (Preferences.getDownloadDirectoryUri() != null) {
+            notifyDataSetChanged();
+        }
+    }
+
     private void bindPlaybackState(@NonNull ViewHolder holder, @NonNull Child song) {
         boolean isCurrent = currentPlayingId != null && currentPlayingId.equals(song.getId());
 

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/AlbumPageFragment.java

@@ -289,7 +289,7 @@ public class AlbumPageFragment extends Fragment implements ClickCallback {
                 bind.songRecyclerView.setLayoutManager(new LinearLayoutManager(requireContext()));
                 bind.songRecyclerView.setHasFixedSize(true);
 
-                songHorizontalAdapter = new SongHorizontalAdapter(this, false, false, album);
+                songHorizontalAdapter = new SongHorizontalAdapter(getViewLifecycleOwner(), this, false, false, album);
                 bind.songRecyclerView.setAdapter(songHorizontalAdapter);
                 setMediaBrowserListenableFuture();
                 reapplyPlayback();

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/ArtistPageFragment.java

@@ -178,7 +178,7 @@ public class ArtistPageFragment extends Fragment implements ClickCallback {
     private void initTopSongsView() {
         bind.mostStreamedSongRecyclerView.setLayoutManager(new LinearLayoutManager(requireContext()));
 
-        songHorizontalAdapter = new SongHorizontalAdapter(this, true, true, null);
+        songHorizontalAdapter = new SongHorizontalAdapter(getViewLifecycleOwner(), this, true, true, null);
         bind.mostStreamedSongRecyclerView.setAdapter(songHorizontalAdapter);
         setMediaBrowserListenableFuture();
         reapplyPlayback();

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/HomeTabMusicFragment.java

@@ -600,7 +600,7 @@ public class HomeTabMusicFragment extends Fragment implements ClickCallback {
 
         bind.topSongsRecyclerView.setHasFixedSize(true);
 
-        topSongAdapter = new SongHorizontalAdapter(this, true, false, null);
+        topSongAdapter = new SongHorizontalAdapter(getViewLifecycleOwner(), this, true, false, null);
         bind.topSongsRecyclerView.setAdapter(topSongAdapter);
         setTopSongsMediaBrowserListenableFuture();
         reapplyTopSongsPlayback();
@@ -641,7 +641,7 @@ public class HomeTabMusicFragment extends Fragment implements ClickCallback {
 
         bind.starredTracksRecyclerView.setHasFixedSize(true);
 
-        starredSongAdapter = new SongHorizontalAdapter(this, true, false, null);
+        starredSongAdapter = new SongHorizontalAdapter(getViewLifecycleOwner(), this, true, false, null);
         bind.starredTracksRecyclerView.setAdapter(starredSongAdapter);
         setStarredSongsMediaBrowserListenableFuture();
         reapplyStarredSongsPlayback();

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/PlaylistPageFragment.java

@@ -264,7 +264,7 @@ public class PlaylistPageFragment extends Fragment implements ClickCallback {
         bind.songRecyclerView.setLayoutManager(new LinearLayoutManager(requireContext()));
         bind.songRecyclerView.setHasFixedSize(true);
 
-        songHorizontalAdapter = new SongHorizontalAdapter(this, true, false, null);
+        songHorizontalAdapter = new SongHorizontalAdapter(getViewLifecycleOwner(), this, true, false, null);
         bind.songRecyclerView.setAdapter(songHorizontalAdapter);
         setMediaBrowserListenableFuture();
         reapplyPlayback();

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/SearchFragment.java

@@ -121,7 +121,7 @@ public class SearchFragment extends Fragment implements ClickCallback {
         bind.searchResultTracksRecyclerView.setLayoutManager(new LinearLayoutManager(requireContext()));
         bind.searchResultTracksRecyclerView.setHasFixedSize(true);
 
-        songHorizontalAdapter = new SongHorizontalAdapter(this, true, false, null);
+        songHorizontalAdapter = new SongHorizontalAdapter(getViewLifecycleOwner(), this, true, false, null);
         setMediaBrowserListenableFuture();
         reapplyPlayback();
 

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/SongListPageFragment.java

@@ -201,7 +201,7 @@ public class SongListPageFragment extends Fragment implements ClickCallback {
         bind.songListRecyclerView.setLayoutManager(new LinearLayoutManager(requireContext()));
         bind.songListRecyclerView.setHasFixedSize(true);
 
-        songHorizontalAdapter = new SongHorizontalAdapter(this, true, false, null);
+        songHorizontalAdapter = new SongHorizontalAdapter(getViewLifecycleOwner(), this, true, false, null);
         bind.songListRecyclerView.setAdapter(songHorizontalAdapter);
         setMediaBrowserListenableFuture();
         reapplyPlayback();

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/bottomsheetdialog/AlbumBottomSheetDialog.java

@@ -13,6 +13,7 @@ import android.widget.TextView;
 import android.widget.Toast;
 import android.widget.ToggleButton;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.lifecycle.ViewModelProvider;
 import androidx.media3.common.MediaItem;
@@ -56,6 +57,10 @@ public class AlbumBottomSheetDialog extends BottomSheetDialogFragment implements
     private AlbumBottomSheetViewModel albumBottomSheetViewModel;
     private AlbumID3 album;
 
+    private TextView removeAllTextView;
+    private List<Child> currentAlbumTracks = Collections.emptyList();
+    private List<MediaItem> currentAlbumMediaItems = Collections.emptyList();
+
     private ListenableFuture<MediaBrowser> mediaBrowserListenableFuture;
 
     @Nullable
@@ -74,6 +79,12 @@ public class AlbumBottomSheetDialog extends BottomSheetDialogFragment implements
         return view;
     }
 
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        MappingUtil.observeExternalAudioRefresh(getViewLifecycleOwner(), this::updateRemoveAllVisibility);
+    }
+
     @Override
     public void onStart() {
         super.onStart();
@@ -188,23 +199,23 @@ public class AlbumBottomSheetDialog extends BottomSheetDialogFragment implements
             });
         });
 
-        TextView removeAll = view.findViewById(R.id.remove_all_text_view);
+        removeAllTextView = view.findViewById(R.id.remove_all_text_view);
         albumBottomSheetViewModel.getAlbumTracks().observe(getViewLifecycleOwner(), songs -> {
-            List<MediaItem> mediaItems = MappingUtil.mapDownloads(songs);
+            currentAlbumTracks = songs != null ? songs : Collections.emptyList();
-            List<Download> downloads = songs.stream().map(Download::new).collect(Collectors.toList());
+            currentAlbumMediaItems = MappingUtil.mapDownloads(currentAlbumTracks);
 
-            removeAll.setOnClickListener(v -> {
+            removeAllTextView.setOnClickListener(v -> {
                 if (Preferences.getDownloadDirectoryUri() == null) {
-                    DownloadUtil.getDownloadTracker(requireContext()).remove(mediaItems, downloads);
+                    List<Download> downloads = currentAlbumTracks.stream().map(Download::new).collect(Collectors.toList());
+                    DownloadUtil.getDownloadTracker(requireContext()).remove(currentAlbumMediaItems, downloads);
                 } else {
-                    songs.forEach(ExternalAudioReader::delete);
+                    currentAlbumTracks.forEach(ExternalAudioReader::delete);
                 }
                 dismissBottomSheet();
             });
+            updateRemoveAllVisibility();
         });
 
-        initDownloadUI(removeAll);
-
         TextView goToArtist = view.findViewById(R.id.go_to_artist_text_view);
         goToArtist.setOnClickListener(v -> albumBottomSheetViewModel.getArtist().observe(getViewLifecycleOwner(), artist -> {
             if (artist != null) {
@@ -244,21 +255,29 @@ public class AlbumBottomSheetDialog extends BottomSheetDialogFragment implements
         dismiss();
     }
 
-    private void initDownloadUI(TextView removeAll) {
+    private void updateRemoveAllVisibility() {
-        albumBottomSheetViewModel.getAlbumTracks().observe(getViewLifecycleOwner(), songs -> {
+        if (removeAllTextView == null) {
-            List<MediaItem> mediaItems = MappingUtil.mapDownloads(songs);
+            return;
+        }
+
+        if (currentAlbumTracks == null || currentAlbumTracks.isEmpty()) {
+            removeAllTextView.setVisibility(View.GONE);
+            return;
+        }
 
         if (Preferences.getDownloadDirectoryUri() == null) {
-                if (DownloadUtil.getDownloadTracker(requireContext()).areDownloaded(mediaItems)) {
+            List<MediaItem> mediaItems = currentAlbumMediaItems;
-                    removeAll.setVisibility(View.VISIBLE);
+            if (mediaItems == null || mediaItems.isEmpty()) {
+                removeAllTextView.setVisibility(View.GONE);
+            } else if (DownloadUtil.getDownloadTracker(requireContext()).areDownloaded(mediaItems)) {
+                removeAllTextView.setVisibility(View.VISIBLE);
             } else {
-                    removeAll.setVisibility(View.GONE);
+                removeAllTextView.setVisibility(View.GONE);
             }
         } else {
-                boolean hasLocal = songs.stream().anyMatch(song -> ExternalAudioReader.getUri(song) != null);
+            boolean hasLocal = currentAlbumTracks.stream().anyMatch(song -> ExternalAudioReader.getUri(song) != null);
-                removeAll.setVisibility(hasLocal ? View.VISIBLE : View.GONE);
+            removeAllTextView.setVisibility(hasLocal ? View.VISIBLE : View.GONE);
         }
-        });
     }
 
     private void initializeMediaBrowser() {

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/bottomsheetdialog/SongBottomSheetDialog.java

@@ -13,6 +13,7 @@ import android.widget.TextView;
 import android.widget.Toast;
 import android.widget.ToggleButton;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.lifecycle.ViewModelProvider;
 import androidx.media3.common.util.UnstableApi;
@@ -53,6 +54,9 @@ public class SongBottomSheetDialog extends BottomSheetDialogFragment implements
     private SongBottomSheetViewModel songBottomSheetViewModel;
     private Child song;
 
+    private TextView downloadButton;
+    private TextView removeButton;
+
     private ListenableFuture<MediaBrowser> mediaBrowserListenableFuture;
 
     @Nullable
@@ -71,6 +75,12 @@ public class SongBottomSheetDialog extends BottomSheetDialogFragment implements
         return view;
     }
 
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        MappingUtil.observeExternalAudioRefresh(getViewLifecycleOwner(), this::updateDownloadButtons);
+    }
+
     @Override
     public void onStart() {
         super.onStart();
@@ -162,8 +172,8 @@ public class SongBottomSheetDialog extends BottomSheetDialogFragment implements
             dismissBottomSheet();
         });
 
-        TextView download = view.findViewById(R.id.download_text_view);
+        downloadButton = view.findViewById(R.id.download_text_view);
-        download.setOnClickListener(v -> {
+        downloadButton.setOnClickListener(v -> {
             if (Preferences.getDownloadDirectoryUri() == null) {
                 DownloadUtil.getDownloadTracker(requireContext()).download(
                         MappingUtil.mapDownload(song),
@@ -175,8 +185,8 @@ public class SongBottomSheetDialog extends BottomSheetDialogFragment implements
             dismissBottomSheet();
         });
 
-        TextView remove = view.findViewById(R.id.remove_text_view);
+        removeButton = view.findViewById(R.id.remove_text_view);
-        remove.setOnClickListener(v -> {
+        removeButton.setOnClickListener(v -> {
             if (Preferences.getDownloadDirectoryUri() == null) {
                 DownloadUtil.getDownloadTracker(requireContext()).remove(
                         MappingUtil.mapDownload(song),
@@ -188,7 +198,7 @@ public class SongBottomSheetDialog extends BottomSheetDialogFragment implements
             dismissBottomSheet();
         });
 
-        initDownloadUI(download, remove);
+        updateDownloadButtons();
 
         TextView addToPlaylist = view.findViewById(R.id.add_to_playlist_text_view);
         addToPlaylist.setOnClickListener(v -> {
@@ -256,21 +266,19 @@ public class SongBottomSheetDialog extends BottomSheetDialogFragment implements
         dismiss();
     }
 
-    private void initDownloadUI(TextView download, TextView remove) {
+    private void updateDownloadButtons() {
+        if (downloadButton == null || removeButton == null) {
+            return;
+        }
+
         if (Preferences.getDownloadDirectoryUri() == null) {
-            if (DownloadUtil.getDownloadTracker(requireContext()).isDownloaded(song.getId())) {
+            boolean downloaded = DownloadUtil.getDownloadTracker(requireContext()).isDownloaded(song.getId());
-                remove.setVisibility(View.VISIBLE);
+            downloadButton.setVisibility(downloaded ? View.GONE : View.VISIBLE);
+            removeButton.setVisibility(downloaded ? View.VISIBLE : View.GONE);
         } else {
-                download.setVisibility(View.VISIBLE);
+            boolean hasLocal = ExternalAudioReader.getUri(song) != null;
-                remove.setVisibility(View.GONE);
+            downloadButton.setVisibility(hasLocal ? View.GONE : View.VISIBLE);
-            }
+            removeButton.setVisibility(hasLocal ? View.VISIBLE : View.GONE);
-        } else {
-            if (ExternalAudioReader.getUri(song) != null) {
-                remove.setVisibility(View.VISIBLE);
-            } else {
-                download.setVisibility(View.VISIBLE);
-                remove.setVisibility(View.GONE);
-            }
         }
     }
 

app/src/main/java/com/cappielloantonio/tempo/util/ExternalAudioReader.java

@@ -1,8 +1,12 @@
 package com.cappielloantonio.tempo.util;
 
 import android.net.Uri;
+import android.os.Looper;
+import android.os.SystemClock;
 
 import androidx.documentfile.provider.DocumentFile;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
 
 import com.cappielloantonio.tempo.App;
 import com.cappielloantonio.tempo.subsonic.models.Child;
@@ -14,11 +18,20 @@ import java.util.HashSet;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 public class ExternalAudioReader {
 
-    private static final Map<String, DocumentFile> cache = new HashMap<>();
+    private static final Map<String, DocumentFile> cache = new ConcurrentHashMap<>();
-    private static String cachedDirUri;
+    private static final Object LOCK = new Object();
+    private static final ExecutorService REFRESH_EXECUTOR = Executors.newSingleThreadExecutor();
+    private static final MutableLiveData<Long> refreshEvents = new MutableLiveData<>();
+
+    private static volatile String cachedDirUri;
+    private static volatile boolean refreshInProgress = false;
+    private static volatile boolean refreshQueued = false;
 
     private static String sanitizeFileName(String name) {
         String sanitized = name.replaceAll("[\\/:*?\\\"<>|]", "_");
@@ -33,60 +46,60 @@ public class ExternalAudioReader {
         return s.toLowerCase(Locale.ROOT);
     }
 
-    private static synchronized void ensureCache() {
+    private static void ensureCache() {
         String uriString = Preferences.getDownloadDirectoryUri();
         if (uriString == null) {
+            synchronized (LOCK) {
                 cache.clear();
                 cachedDirUri = null;
+            }
             ExternalDownloadMetadataStore.clear();
             return;
         }
 
-        if (uriString.equals(cachedDirUri)) return;
+        if (uriString.equals(cachedDirUri)) {
+            return;
+        }
 
-        cache.clear();
+        boolean runSynchronously = false;
-        DocumentFile directory = DocumentFile.fromTreeUri(App.getContext(), Uri.parse(uriString));
+        synchronized (LOCK) {
-        Map<String, Long> expectedSizes = ExternalDownloadMetadataStore.snapshot();
+            if (refreshInProgress) {
-        Set<String> verifiedKeys = new HashSet<>();
+                return;
-        if (directory != null && directory.canRead()) {
+            }
-            for (DocumentFile file : directory.listFiles()) {
-                if (file == null || file.isDirectory()) continue;
-                String existing = file.getName();
-                if (existing == null) continue;
 
-                String base = existing.replaceFirst("\\.[^\\.]+$", "");
+            if (Looper.myLooper() == Looper.getMainLooper()) {
-                String key = normalizeForComparison(base);
+                scheduleRefreshLocked();
-                Long expected = expectedSizes.get(key);
+                return;
-                long actualLength = file.length();
+            }
 
-                if (expected != null && expected > 0 && actualLength == expected) {
+            refreshInProgress = true;
-                    cache.put(key, file);
+            runSynchronously = true;
-                    verifiedKeys.add(key);
+        }
-                } else {
+
-                    ExternalDownloadMetadataStore.remove(key);
+        if (runSynchronously) {
+            try {
+                rebuildCache();
+            } finally {
+                onRefreshFinished();
             }
         }
     }
 
-        if (!expectedSizes.isEmpty()) {
+    public static void refreshCache() {
-            if (verifiedKeys.isEmpty()) {
+        refreshCacheAsync();
-                ExternalDownloadMetadataStore.clear();
-            } else {
-                for (String key : expectedSizes.keySet()) {
-                    if (!verifiedKeys.contains(key)) {
-                        ExternalDownloadMetadataStore.remove(key);
-                    }
-                }
-            }
     }
 
-        cachedDirUri = uriString;
+    public static void refreshCacheAsync() {
-    }
+        synchronized (LOCK) {
-
-    public static synchronized void refreshCache() {
             cachedDirUri = null;
             cache.clear();
         }
+        requestRefresh();
+    }
+
+    public static LiveData<Long> getRefreshEvents() {
+        return refreshEvents;
+    }
 
     private static String buildKey(String artist, String title, String album) {
         String name = artist != null && !artist.isEmpty() ? artist + " - " + title : title;
@@ -136,4 +149,96 @@ public class ExternalAudioReader {
         }
         return deleted;
     }
+
+    private static void requestRefresh() {
+        synchronized (LOCK) {
+            scheduleRefreshLocked();
+        }
+    }
+
+    private static void scheduleRefreshLocked() {
+        if (refreshInProgress) {
+            refreshQueued = true;
+            return;
+        }
+
+        refreshInProgress = true;
+        REFRESH_EXECUTOR.execute(() -> {
+            try {
+                rebuildCache();
+            } finally {
+                onRefreshFinished();
+            }
+        });
+    }
+
+    private static void rebuildCache() {
+        String uriString = Preferences.getDownloadDirectoryUri();
+        if (uriString == null) {
+            synchronized (LOCK) {
+                cache.clear();
+                cachedDirUri = null;
+            }
+            ExternalDownloadMetadataStore.clear();
+            return;
+        }
+
+        DocumentFile directory = DocumentFile.fromTreeUri(App.getContext(), Uri.parse(uriString));
+        Map<String, Long> expectedSizes = ExternalDownloadMetadataStore.snapshot();
+        Set<String> verifiedKeys = new HashSet<>();
+        Map<String, DocumentFile> newEntries = new HashMap<>();
+
+        if (directory != null && directory.canRead()) {
+            for (DocumentFile file : directory.listFiles()) {
+                if (file == null || file.isDirectory()) continue;
+                String existing = file.getName();
+                if (existing == null) continue;
+
+                String base = existing.replaceFirst("\\.[^\\.]+$", "");
+                String key = normalizeForComparison(base);
+                Long expected = expectedSizes.get(key);
+                long actualLength = file.length();
+
+                if (expected != null && expected > 0 && actualLength == expected) {
+                    newEntries.put(key, file);
+                    verifiedKeys.add(key);
+                } else {
+                    ExternalDownloadMetadataStore.remove(key);
+                }
+            }
+        }
+
+        if (!expectedSizes.isEmpty()) {
+            if (verifiedKeys.isEmpty()) {
+                ExternalDownloadMetadataStore.clear();
+            } else {
+                for (String key : expectedSizes.keySet()) {
+                    if (!verifiedKeys.contains(key)) {
+                        ExternalDownloadMetadataStore.remove(key);
+                    }
+                }
+            }
+        }
+
+        synchronized (LOCK) {
+            cache.clear();
+            cache.putAll(newEntries);
+            cachedDirUri = uriString;
+        }
+    }
+
+    private static void onRefreshFinished() {
+        boolean runAgain;
+        synchronized (LOCK) {
+            refreshInProgress = false;
+            runAgain = refreshQueued;
+            refreshQueued = false;
+        }
+
+        refreshEvents.postValue(SystemClock.elapsedRealtime());
+
+        if (runAgain) {
+            requestRefresh();
+        }
+    }
 }

app/src/main/java/com/cappielloantonio/tempo/util/ExternalAudioWriter.java

@@ -159,7 +159,7 @@ public class ExternalAudioWriter {
                 if (matches) {
                     ExternalDownloadMetadataStore.recordSize(metadataKey, localLength);
                     recordDownload(child, existingFile.getUri());
-                    ExternalAudioReader.refreshCache();
+                    ExternalAudioReader.refreshCacheAsync();
                     notifyExists(context, fileName);
                     return;
                 } else {
@@ -209,7 +209,7 @@ public class ExternalAudioWriter {
                 ExternalDownloadMetadataStore.recordSize(metadataKey, total);
                 recordDownload(child, targetUri);
                 notifySuccess(context, fileName, child, targetUri);
-                ExternalAudioReader.refreshCache();
+                ExternalAudioReader.refreshCacheAsync();
             }
         } catch (Exception e) {
             if (targetFile != null) {

app/src/main/java/com/cappielloantonio/tempo/util/MappingUtil.java

@@ -4,6 +4,7 @@ import android.net.Uri;
 import android.os.Bundle;
 
 import androidx.annotation.OptIn;
+import androidx.lifecycle.LifecycleOwner;
 import androidx.media3.common.MediaItem;
 import androidx.media3.common.MediaMetadata;
 import androidx.media3.common.MimeTypes;
@@ -240,4 +241,11 @@ public class MappingUtil {
         Download download = new DownloadRepository().getDownload(id);
         return download != null && !download.getDownloadUri().isEmpty() ? Uri.parse(download.getDownloadUri()) : MusicUtil.getDownloadUri(id);
     }
+
+    public static void observeExternalAudioRefresh(LifecycleOwner owner, Runnable onRefresh) {
+        if (owner == null || onRefresh == null) {
+            return;
+        }
+        ExternalAudioReader.getRefreshEvents().observe(owner, event -> onRefresh.run());
+    }
 }