apply the prefetched theme on open and soften the hero darkening

app/src/main/kotlin/com/subtracks/ui/AppRoot.kt

@@ -68,11 +68,14 @@ private object Routes {
     const val LIBRARY = "library"
     const val SETTINGS = "settings"
     const val ADD_SERVER = "add-server"
-    const val ALBUM_DETAIL = "album/{albumId}"
+    const val ALBUM_DETAIL = "album/{albumId}?coverArt={coverArt}"
     const val ARTIST_DETAIL = "artist/{artistId}"
     const val PLAYLIST_DETAIL = "playlist/{playlistId}"
 
-    fun album(id: String) = "album/${Uri.encode(id)}"
+    fun album(
+        id: String,
+        coverArt: String? = null,
+    ) = "album/${Uri.encode(id)}?coverArt=${Uri.encode(coverArt.orEmpty())}"
 
     fun artist(id: String) = "artist/${Uri.encode(id)}"
 
@@ -135,7 +138,7 @@ private fun MainNavigation() {
             ) {
                 composable(Routes.LIBRARY) {
                     LibraryRoute(
-                        onAlbumClick = { album -> navController.navigate(Routes.album(album.id)) },
+                        onAlbumClick = { album -> navController.navigate(Routes.album(album.id, album.coverArt)) },
                         onArtistClick = { artist -> navController.navigate(Routes.artist(artist.id)) },
                         onPlaylistClick = { playlist -> navController.navigate(Routes.playlist(playlist.id)) },
                         onOpenSettings = { navController.navigate(Routes.SETTINGS) },
@@ -150,10 +153,22 @@ private fun MainNavigation() {
                 }
                 composable(
                     route = Routes.ALBUM_DETAIL,
-                    arguments = listOf(navArgument("albumId") { type = NavType.StringType }),
+                    arguments =
+                        listOf(
+                            navArgument("albumId") { type = NavType.StringType },
+                            navArgument("coverArt") {
+                                type = NavType.StringType
+                                defaultValue = ""
+                            },
+                        ),
                 ) { entry ->
                     AlbumDetailRoute(
                         albumId = entry.arguments?.getString("albumId").orEmpty(),
+                        coverArtId =
+                            entry.arguments
+                                ?.getString("coverArt")
+                                .orEmpty()
+                                .ifEmpty { null },
                         onBack = { navController.popBackStack() },
                     )
                 }
@@ -164,7 +179,7 @@ private fun MainNavigation() {
                     ArtistDetailRoute(
                         artistId = entry.arguments?.getString("artistId").orEmpty(),
                         onBack = { navController.popBackStack() },
-                        onAlbumClick = { album -> navController.navigate(Routes.album(album.id)) },
+                        onAlbumClick = { album -> navController.navigate(Routes.album(album.id, album.coverArt)) },
                     )
                 }
                 composable(

app/src/main/kotlin/com/subtracks/ui/library/AlbumDetailScreen.kt

@@ -89,6 +89,7 @@ private const val THEME_TRANSITION_MS = 100
 @Composable
 fun AlbumDetailRoute(
     albumId: String,
+    coverArtId: String?,
     onBack: () -> Unit,
     viewModel: AlbumDetailViewModel = koinViewModel(key = albumId) { parametersOf(albumId) },
     playbackController: PlaybackController = koinInject(),
@@ -97,11 +98,12 @@ fun AlbumDetailRoute(
     val songs by viewModel.songs.collectAsStateWithLifecycle(initialValue = emptyList())
     val playback by playbackController.state.collectAsStateWithLifecycle()
     val context = playback.context
+    val shortcutArt = remember(coverArtId) { coverArtId?.let { viewModel.coverArt(it, true) } }
     AlbumDetailScreen(
         album = album,
         songs = songs,
         coverArt = viewModel::coverArt,
-        artwork = rememberArtworkColors(viewModel.coverArt(album?.coverArt, true), THEME_TRANSITION_MS),
+        artwork = rememberArtworkColors(shortcutArt ?: viewModel.coverArt(album?.coverArt, true), THEME_TRANSITION_MS),
         onBack = onBack,
         onSongClick = viewModel::play,
         playingSongId = playback.item?.id.takeIf { context?.kind == QueueKind.Album && context.refId == albumId },

app/src/main/kotlin/com/subtracks/ui/theme/ArtworkSeedCache.kt

@@ -44,6 +44,8 @@ object ArtworkSeedCache {
         this.store = store
     }
 
+    fun cached(cacheKey: String): Pair<Int, Int?>? = cache.get(cacheKey)
+
     suspend fun seeds(
         context: Context,
         ref: CoverArtRef,

app/src/main/kotlin/com/subtracks/ui/theme/ArtworkTheme.kt

@@ -27,7 +27,7 @@ private const val BLOB_COUNT = 4
 private const val ACCENT_MAX_LUMINANCE = 0.18f
 private const val PRIMARY_MIN_LUMINANCE = 0.30f
 private const val MIN_GRADIENT_SATURATION = 0.30f
-private const val HERO_DARKEN_MAX = 1.0f
+private const val HERO_DARKEN_MAX = 0.88f
 private const val DARKEN_START_SCREENS = 0.5f
 private const val DARKEN_END_SCREENS = 1.5f
 private const val DARKEN_KNEE = 0.2f
@@ -166,8 +166,10 @@ fun rememberArtworkColors(
     ref: CoverArtRef?,
     durationMillis: Int = ARTWORK_THEME_TRANSITION_MS,
 ): ArtworkColors {
+    val cached = remember(ref?.cacheKey) { ref?.cacheKey?.let(ArtworkSeedCache::cached) }
     val seeds by rememberArtworkSeed(ref)
-    val target = remember(seeds) { seeds?.let { (primary, secondary) -> artworkColorsFromSeeds(primary, secondary) } }
+    val effective = seeds ?: cached
+    val target = remember(effective) { effective?.let { (primary, secondary) -> artworkColorsFromSeeds(primary, secondary) } }
     return rememberAnimatedArtworkColors(target, durationMillis)
 }