refactor: further address code health issues in media and UI components

- Consolidate MediaStore logic in ArtResolver.
- Fix global conditionals in GramophonePlaybackService.
- Refactor ViewPagerFragment.onCreateView for better modularity.
- Reduce argument count in LibraryTreeLoader using MediaItemConfig.

Continuing cleanup based on CodeScene feedback.

Author: banksio

app/src/main/java/org/akanework/gramophone/logic/GramophonePlaybackService.kt

@@ -264,55 +264,58 @@ class GramophonePlaybackService : MediaLibraryService(), MediaSessionService.Lis
         else
             customCommands[0]
 
-    private val timer: Runnable = Runnable {
+    private val timer = Runnable { handleTimerExpired() }
+    
+    private fun handleTimerExpired() {
         if (timerPauseOnEnd) {
-            endedWorkaroundPlayer!!.exoPlayer.pauseAtEndOfMediaItems = true
+            endedWorkaroundPlayer?.exoPlayer?.pauseAtEndOfMediaItems = true
         } else {
-            controller!!.pause()
+            controller?.pause()
         }
         timerDuration = null
     }
+
     private var timerPauseOnEnd = false
     private var timerDuration: Long? = null
         set(value) {
             field = value
-            if (value != null && value > 0) {
-                handler.postDelayed(timer, value - SystemClock.elapsedRealtime())
-            } else {
-                handler.removeCallbacks(timer)
-            }
-            mediaSession!!.broadcastCustomCommand(
-                SessionCommand(SERVICE_TIMER_CHANGED, Bundle.EMPTY),
-                Bundle.EMPTY
-            )
+            updateTimerSchedule(value)
+            mediaSession?.broadcastCustomCommand(SessionCommand(SERVICE_TIMER_CHANGED, Bundle.EMPTY), Bundle.EMPTY)
         }
 
+    private fun updateTimerSchedule(value: Long?) {
+        handler.removeCallbacks(timer)
+        if (value != null && value > 0) {
+            handler.postDelayed(timer, value - SystemClock.elapsedRealtime())
+        }
+    }
+
     private val seekReceiver = object : BroadcastReceiver() {
         override fun onReceive(context: Context, intent: Intent) {
-            val to =
-                intent.extras?.getLong("seekTo", C.INDEX_UNSET.toLong()) ?: C.INDEX_UNSET.toLong()
-            if (to != C.INDEX_UNSET.toLong())
+            val to = intent.extras?.getLong("seekTo", C.INDEX_UNSET.toLong()) ?: C.INDEX_UNSET.toLong()
+            if (to != C.INDEX_UNSET.toLong()) {
                 controller?.seekTo(to)
+            }
         }
     }
 
     private val btReceiver = object : BroadcastReceiver() {
         override fun onReceive(context: Context, intent: Intent) {
-            if (intent.action.equals("android.bluetooth.a2dp.profile.action.CODEC_CONFIG_CHANGED") &&
-                Build.VERSION.SDK_INT >= Build.VERSION_CODES.O /* before 8, only sbc was supported */
+            if (intent.action == "android.bluetooth.a2dp.profile.action.CODEC_CONFIG_CHANGED" &&
+                Build.VERSION.SDK_INT >= Build.VERSION_CODES.O
             ) {
-                btInfo = BtCodecInfo.fromCodecConfig(
-                    @SuppressLint("NewApi") IntentCompat.getParcelableExtra(
-                        intent,
-                        "android.bluetooth.extra.CODEC_STATUS",
-                        BluetoothCodecStatus::class.java
-                    )?.codecConfig
-                )
-                Log.d(TAG, "new bluetooth codec config $btInfo")
+                handleBluetoothCodecChange(intent)
             }
         }
     }
 
+    @SuppressLint("NewApi")
+    private fun handleBluetoothCodecChange(intent: Intent) {
+        val status = IntentCompat.getParcelableExtra(intent, "android.bluetooth.extra.CODEC_STATUS", BluetoothCodecStatus::class.java)
+        btInfo = BtCodecInfo.fromCodecConfig(status?.codecConfig)
+        Log.d(TAG, "new bluetooth codec config $btInfo")
+    }
+
     override fun onCreate() {
         Log.i(TAG, "+onCreate()")
         super.onCreate()
@@ -1229,7 +1232,7 @@ class GramophonePlaybackService : MediaLibraryService(), MediaSessionService.Lis
 
     private fun refreshMediaButtonCustomLayout() {
         val isEmpty = controller?.currentTimeline?.isEmpty != false
-        mediaSession!!.connectedControllers.forEach {
+        mediaSession?.connectedControllers?.forEach {
             if (mediaSession!!.isMediaNotificationController(it)
                 || mediaSession!!.isAutoCompanionController(it)
                 || mediaSession!!.isAutomotiveController(it)

app/src/main/java/org/akanework/gramophone/logic/LibraryTreeLoader.kt

@@ -48,6 +48,18 @@ class LibraryTreeLoader(
         val startIndex: Int? = null
     )
 
+    /** Configuration for creating a folder MediaItem. */
+    private data class MediaItemConfig(
+        val id: String,
+        val title: String,
+        val mediaType: Int,
+        val subtitle: String? = null,
+        val extras: Bundle? = null,
+        val artworkUri: android.net.Uri? = null,
+        val isPlayable: Boolean = false,
+        val isBrowsable: Boolean = true
+    )
+
     // --- Helpers ---
 
     private fun getEnabledTabs(): List<ViewPager2Adapter.Companion.Tab> {
@@ -64,15 +76,15 @@ class LibraryTreeLoader(
             putInt(MediaConstants.EXTRAS_KEY_CONTENT_STYLE_PLAYABLE, MediaConstants.EXTRAS_VALUE_CONTENT_STYLE_GRID_ITEM)
         }
         return when (id) {
-            "root" -> createFolderItem("root", "", MediaMetadata.MEDIA_TYPE_FOLDER_MIXED)
-            "more" -> createFolderItem("more", context.getString(R.string.more), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED)
-            "songs" -> createFolderItem("songs", context.getString(R.string.category_songs), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED)
-            "albums" -> createFolderItem("albums", context.getString(R.string.category_albums), MediaMetadata.MEDIA_TYPE_FOLDER_ALBUMS, extras = gridExtras)
-            "artists" -> createFolderItem("artists", context.getString(R.string.category_artists), MediaMetadata.MEDIA_TYPE_FOLDER_ARTISTS, extras = gridExtras)
-            "genres" -> createFolderItem("genres", context.getString(R.string.category_genres), MediaMetadata.MEDIA_TYPE_FOLDER_GENRES)
-            "dates" -> createFolderItem("dates", context.getString(R.string.category_dates), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED)
-            "folders" -> createFolderItem("folders", context.getString(R.string.folders), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED)
-            "playlists" -> createFolderItem("playlists", context.getString(R.string.category_playlists), MediaMetadata.MEDIA_TYPE_FOLDER_PLAYLISTS)
+            "root" -> createFolderItem(MediaItemConfig("root", "", MediaMetadata.MEDIA_TYPE_FOLDER_MIXED))
+            "more" -> createFolderItem(MediaItemConfig("more", context.getString(R.string.more), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED))
+            "songs" -> createFolderItem(MediaItemConfig("songs", context.getString(R.string.category_songs), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED))
+            "albums" -> createFolderItem(MediaItemConfig("albums", context.getString(R.string.category_albums), MediaMetadata.MEDIA_TYPE_FOLDER_ALBUMS, extras = gridExtras))
+            "artists" -> createFolderItem(MediaItemConfig("artists", context.getString(R.string.category_artists), MediaMetadata.MEDIA_TYPE_FOLDER_ARTISTS, extras = gridExtras))
+            "genres" -> createFolderItem(MediaItemConfig("genres", context.getString(R.string.category_genres), MediaMetadata.MEDIA_TYPE_FOLDER_GENRES))
+            "dates" -> createFolderItem(MediaItemConfig("dates", context.getString(R.string.category_dates), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED))
+            "folders" -> createFolderItem(MediaItemConfig("folders", context.getString(R.string.folders), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED))
+            "playlists" -> createFolderItem(MediaItemConfig("playlists", context.getString(R.string.category_playlists), MediaMetadata.MEDIA_TYPE_FOLDER_PLAYLISTS))
             else -> null
         }
     }
@@ -90,15 +102,27 @@ class LibraryTreeLoader(
     }
 
     private fun mapAlbumToMediaItem(item: Album): MediaItem = createFolderItem(
-        "album_${item.id}", item.title ?: "", MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
-        subtitle = item.albumArtist ?: item.songList.firstOrNull()?.mediaMetadata?.artist?.toString(),
-        artworkUri = item.cover, isPlayable = true, isBrowsable = false
+        MediaItemConfig(
+            id = "album_${item.id}",
+            title = item.title ?: "",
+            mediaType = MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
+            subtitle = item.albumArtist ?: item.songList.firstOrNull()?.mediaMetadata?.artist?.toString(),
+            artworkUri = item.cover,
+            isPlayable = true,
+            isBrowsable = false
+        )
     )
 
     private fun mapArtistToMediaItem(item: Artist): MediaItem = createFolderItem(
-        "artist_${item.title}", item.title ?: "", MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
-        subtitle = context.resources.getQuantityString(R.plurals.songs, item.songList.size, item.songList.size),
-        artworkUri = item.albumList.firstOrNull()?.cover, isPlayable = true, isBrowsable = false
+        MediaItemConfig(
+            id = "artist_${item.title}",
+            title = item.title ?: "",
+            mediaType = MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
+            subtitle = context.resources.getQuantityString(R.plurals.songs, item.songList.size, item.songList.size),
+            artworkUri = item.albumList.firstOrNull()?.cover,
+            isPlayable = true,
+            isBrowsable = false
+        )
     )
 
     private fun mapPlaylistToMediaItem(item: Playlist): MediaItem {
@@ -117,25 +141,42 @@ class LibraryTreeLoader(
             is uk.akane.libphonograph.dynamicitem.Favorite -> "playlist_favorite"
             else -> "playlist_${item.id}"
         }
-        return createFolderItem(id, title, MediaMetadata.MEDIA_TYPE_FOLDER_MIXED, artworkUri = icon, isPlayable = true, isBrowsable = false)
+        return createFolderItem(MediaItemConfig(id, title, MediaMetadata.MEDIA_TYPE_FOLDER_MIXED, artworkUri = icon, isPlayable = true, isBrowsable = false))
     }
 
     private fun mapGenreToMediaItem(item: Genre): MediaItem = createFolderItem(
-        "genre_${item.id}", item.title ?: context.getString(R.string.unknown_genre), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
-        subtitle = context.resources.getQuantityString(R.plurals.songs, item.songList.size, item.songList.size),
-        isPlayable = true, isBrowsable = false, artworkUri = null
+        MediaItemConfig(
+            id = "genre_${item.id}",
+            title = item.title ?: context.getString(R.string.unknown_genre),
+            mediaType = MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
+            subtitle = context.resources.getQuantityString(R.plurals.songs, item.songList.size, item.songList.size),
+            isPlayable = true,
+            isBrowsable = false,
+            artworkUri = null
+        )
     )
 
     private fun mapDateToMediaItem(item: Date): MediaItem = createFolderItem(
-        "date_${item.id}", item.title ?: context.getString(R.string.unknown_year), MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
-        subtitle = context.resources.getQuantityString(R.plurals.songs, item.songList.size, item.songList.size),
-        isPlayable = true, isBrowsable = false, artworkUri = null
+        MediaItemConfig(
+            id = "date_${item.id}",
+            title = item.title ?: context.getString(R.string.unknown_year),
+            mediaType = MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
+            subtitle = context.resources.getQuantityString(R.plurals.songs, item.songList.size, item.songList.size),
+            isPlayable = true,
+            isBrowsable = false,
+            artworkUri = null
+        )
     )
 
     private fun mapFileNodeToMediaItem(item: FileNode): MediaItem = createFolderItem(
-        "folder_${item.folderName}", item.folderName, MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
-        subtitle = context.resources.getQuantityString(R.plurals.items, item.folderList.size + item.songList.size, item.folderList.size + item.songList.size),
-        isPlayable = true, isBrowsable = false
+        MediaItemConfig(
+            id = "folder_${item.folderName}",
+            title = item.folderName,
+            mediaType = MediaMetadata.MEDIA_TYPE_FOLDER_MIXED,
+            subtitle = context.resources.getQuantityString(R.plurals.items, item.folderList.size + item.songList.size, item.folderList.size + item.songList.size),
+            isPlayable = true,
+            isBrowsable = false
+        )
     )
 
     private suspend fun getSongsInParent(parentId: String): List<MediaItem> {
@@ -303,17 +344,21 @@ class LibraryTreeLoader(
         else -> app.reader.songListFlow.first().find { it.mediaId == mediaId }
     }
 
-    private fun createFolderItem(
-        id: String, title: String, mediaType: Int, subtitle: String? = null,
-        extras: Bundle? = null, artworkUri: android.net.Uri? = null,
-        isPlayable: Boolean = false, isBrowsable: Boolean = true
-    ): MediaItem {
+    private fun createFolderItem(config: MediaItemConfig): MediaItem {
         val metadataBuilder = MediaMetadata.Builder()
-            .setTitle(title).setSubtitle(subtitle).setIsBrowsable(isBrowsable)
-            .setIsPlayable(isPlayable).setMediaType(mediaType)
-        if (extras != null) metadataBuilder.setExtras(extras)
-        if (artworkUri != null) metadataBuilder.setArtworkUri(artworkUri)
-        return MediaItem.Builder().setMediaId(id).setMediaMetadata(metadataBuilder.build()).build()
+            .setTitle(config.title)
+            .setSubtitle(config.subtitle)
+            .setIsBrowsable(config.isBrowsable)
+            .setIsPlayable(config.isPlayable)
+            .setMediaType(config.mediaType)
+        
+        config.extras?.let { metadataBuilder.setExtras(it) }
+        config.artworkUri?.let { metadataBuilder.setArtworkUri(it) }
+        
+        return MediaItem.Builder()
+            .setMediaId(config.id)
+            .setMediaMetadata(metadataBuilder.build())
+            .build()
     }
 
     fun getSearchResult(