Merge pull request #3132 from wuqqers/fix/desugar-jdk-libs-nio

fix(android): use desugar_jdk_libs_nio so NewPipeExtractor works on minSdk 28

composeApp/build.gradle.kts

@@ -449,7 +449,7 @@ nucleus.application {
         "--enable-native-access=ALL-UNNAMED", // need for JNA for compose-webview (wry) to work
         // --- ADD THESE FOR SPEED & LOW RAM ---
         "-Xms64m",                  // Start with a tiny heap (prevents grabbing 500MB upfront)
-        "-Xmx384m",                 // Cap the max heap (VLC and WebView need a bit of room)
+        "-Xmx1g",                   // Ceiling, not a reservation: the heap only grows to what is live (#3200, #3193)
         "-XX:TieredStopAtLevel=1",  // Disables the heavy C2 compiler. Huge startup speedup!
         "-XX:+UseSerialGC"          // The Serial GC is the most efficient for heaps under 512MB
     )
@@ -556,7 +556,7 @@ nucleus.application {
         // ProGuard is not used for native images; -Os is the size equivalent
         optimization = NativeImageOptimization.SIZE
         // Same ceiling as the JVM distribution's -Xmx
-        maxHeapSize = "384m"
+        maxHeapSize = "1g"
         // Skiko is loaded from lib/ next to the binary (Nucleus copies it there); don't embed
         // a second ~30 MB copy as a resource
         buildArgs.add("-H:+UnlockExperimentalVMOptions")

composeApp/src/commonMain/kotlin/org/spotube/spotube/core/audioplayer/AudioPlayerModels.kt

@@ -21,6 +21,7 @@ import org.spotube.plugin_interfaces.plugin_apis.audio.StreamProtocol
 import org.spotube.plugin_interfaces.plugin_apis.metadata.track.MetadataTrack
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
+import kotlinx.serialization.Transient
 import kotlin.time.Duration
 
 data class MediaItem(
@@ -84,7 +85,9 @@ sealed interface QueueEntry {
         val artists: List<String>,
         val duration: Long,
         val album: String?,
-        val coverBytes: ByteArray?,
+        // Not persisted: the queue is saved on every change and covers made it hundreds of MB
+        // of JSON (#3193). Restore fills them back in from the local media index.
+        @Transient val coverBytes: ByteArray? = null,
         override val url: String,
         override val addedBy: String = "") : QueueEntry {
         override val artworkUrl: String? get() = null

composeApp/src/commonMain/kotlin/org/spotube/spotube/core/audioplayer/DeviceAudioPlayerQueue.kt

@@ -20,8 +20,10 @@ package org.spotube.spotube.core.audioplayer
 import org.spotube.plugin_interfaces.plugin_apis.audio.StreamProtocol
 import org.spotube.spotube.core.di.injectLogger
 import org.spotube.spotube.modules.blacklist.BlacklistRepository
+import org.spotube.spotube.modules.library.local_tracks.media.LocalMediaCacheRepository
 import org.spotube.spotube.modules.plugin.PluginProvider
 import org.spotube.spotube.modules.settings.SettingsProvider
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.IO
@@ -37,6 +39,7 @@ import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import org.koin.core.component.KoinComponent
+import org.koin.core.component.get
 import kotlin.random.Random
 import kotlin.time.Duration.Companion.milliseconds
 
@@ -130,14 +133,15 @@ class DeviceAudioPlayerQueue(
         startPosition: Int,
         collectionEntry: QueueCollectionEntry?) {
         logger.i { "Loading queue with ${entries.size} entries, autoPlay=$autoPlay, startPosition=$startPosition" }
-        val mediaItems = entries.mapNotNull { it.toMediaItem() }
+        val resolved = resolveMediaItems(entries)
+        val mediaItems = resolved.map { it.first }
         if (mediaItems.isEmpty()) {
             logger.w { "load: no valid media items after filtering blanks" }
         }
         val normalizedStartPosition =
             if (mediaItems.isEmpty()) 0 else startPosition.coerceIn(0, mediaItems.lastIndex)
         logger.d { "Normalized start position: $startPosition -> $normalizedStartPosition" }
-        entryByMediaUrl.value = mediaItems.associate { it.url to entries.firstOrNull { e -> e.toMediaItem()?.url == it.url }!! }
+        entryByMediaUrl.value = entriesByUrl(resolved)
         updateCollectionContext(collectionEntry)
         audioPlayer.load(mediaItems, autoPlay, normalizedStartPosition)
         persistQueueStateIfReady()
@@ -401,19 +405,66 @@ class DeviceAudioPlayerQueue(
             return
         }
 
-        val mediaItems = state.entries.mapNotNull { it.toMediaItem() }
-        if (mediaItems.isEmpty()) {
+        val restored = resolveMediaItems(withLocalCovers(state.entries))
+        if (restored.isEmpty()) {
             logger.w { "restorePersistedState: all entries had blank urls" }
             return
         }
-        entryByMediaUrl.value = mediaItems.associate { it.url to state.entries.firstOrNull { e -> e.toMediaItem()?.url == it.url }!! }
+        val mediaItems = restored.map { it.first }
+        entryByMediaUrl.value = entriesByUrl(restored)
         val normalizedStartPosition = state.currentIndex.coerceIn(0, mediaItems.lastIndex)
         logger.d { "Loading restored playlist with normalized start position: ${state.currentIndex} -> $normalizedStartPosition" }
         audioPlayer.load(mediaItems, autoPlay = false, startPosition = normalizedStartPosition)
         logger.i { "Persisted state restored successfully" }
     }
 
+    /**
+     * Converts each entry once. Looking every item's entry up again by converting the whole list
+     * per item was quadratic: ~900k suspending conversions to start a 1353-track playlist.
+     */
+    private suspend fun resolveMediaItems(entries: List<QueueEntry>): List<Pair<MediaItem, QueueEntry>> =
+        entries.mapNotNull { entry -> entry.toMediaItem()?.let { it to entry } }
+
+    /** First entry wins for a repeated url, as before. */
+    private fun entriesByUrl(resolved: List<Pair<MediaItem, QueueEntry>>): Map<String, QueueEntry> = buildMap {
+        resolved.forEach { (item, entry) -> if (item.url !in this) put(item.url, entry) }
+    }
+
+    /** Local covers aren't persisted with the queue; look them up in the local media index. */
+    private suspend fun withLocalCovers(entries: List<QueueEntry>): List<QueueEntry> {
+        if (entries.none { it is QueueEntry.LocalTrack }) return entries
+        val covers = runCatching {
+            get<LocalMediaCacheRepository>().cacheFlow.first().folders
+                .flatMap { it.tracks }
+                .mapNotNull { track -> track.coverBytes?.let { track.path to it } }
+                .toMap()
+        }.getOrElse {
+            logger.w(it) { "Couldn't read local media index for queue covers" }
+            emptyMap()
+        }
+        if (covers.isEmpty()) return entries
+        return entries.map { entry ->
+            if (entry is QueueEntry.LocalTrack && entry.coverBytes == null) {
+                covers[entry.url]?.let { entry.copy(coverBytes = it) } ?: entry
+            } else entry
+        }
+    }
+
+    /**
+     * Runs from fire-and-forget collectors on a scope without an exception handler, where a
+     * failed write (disk full, I/O error) would otherwise crash the app. Losing one save is fine.
+     */
     private suspend fun persistQueueStateIfReady() {
+        try {
+            persistQueueState()
+        } catch (e: CancellationException) {
+            throw e
+        } catch (e: Exception) {
+            logger.e(e) { "Failed to persist queue state" }
+        }
+    }
+
+    private suspend fun persistQueueState() {
         if (isRestoringPersistedState) {
             logger.v { "Skipping persist: still restoring persisted state" }
             return

composeApp/src/commonMain/kotlin/org/spotube/spotube/core/db/Database.kt

@@ -61,13 +61,13 @@ class Database(val paths: Paths) {
 
     val audioPlayerQueueDataStore: DataStore<Preferences> by lazy {
         PreferenceDataStoreFactory.createWithPath(
-            produceFile = { "${paths.getApplicationDataDirPath()}/spotube_audio_player_queue.preferences_pb".toPath() }
+            produceFile = { dropIfOversized("${paths.getApplicationDataDirPath()}/spotube_audio_player_queue.preferences_pb".toPath()) }
         )
     }
 
     val localMediaDataStore: DataStore<Preferences> by lazy {
         PreferenceDataStoreFactory.createWithPath(
-            produceFile = { "${paths.getApplicationDataDirPath()}/spotube_local_media.preferences_pb".toPath() }
+            produceFile = { dropIfOversized("${paths.getApplicationDataDirPath()}/spotube_local_media.preferences_pb".toPath()) }
         )
     }
 
@@ -83,7 +83,23 @@ class Database(val paths: Paths) {
         )
     }
 
+    /**
+     * DataStore reads a whole preferences file into the heap. Earlier builds stored full-size
+     * embedded covers as JSON number arrays in the queue and local media stores, growing them to
+     * hundreds of MB and crashing with OutOfMemoryError on load (#3193). Both are rebuildable, so
+     * drop one that is far past any sane size instead of loading it.
+     */
+    private fun dropIfOversized(path: okio.Path): okio.Path {
+        runCatching {
+            val size = FileSystem.SYSTEM.metadataOrNull(path)?.size ?: return path
+            if (size > MAX_CACHE_STORE_BYTES) FileSystem.SYSTEM.delete(path)
+        }
+        return path
+    }
+
     private companion object {
+        const val MAX_CACHE_STORE_BYTES = 8L * 1024 * 1024
+
         /** Preference files written by previous launches; their presence means an upgrade. */
         val EXISTING_INSTALL_PROBE_FILES = listOf(
             "spotube.preferences_pb",

composeApp/src/commonMain/kotlin/org/spotube/spotube/core/server/CacheManager.kt

@@ -196,22 +196,18 @@ class CacheManager(
                 val (start, end) = range
                 val length = end - start + 1
                 val contentRange = "bytes $start-$end/$fileSize"
-                fileSystem.source(filePath).buffer().use { source ->
-                    source.skip(start)
-                    val bytes = source.readByteArray(length)
-                    call.respond(object : OutgoingContent.WriteChannelContent() {
-                        override val status: HttpStatusCode = HttpStatusCode.PartialContent
-                        override val contentLength: Long = bytes.size.toLong()
-                        override val contentType: ContentType = entry.toContentType()
-                        override val headers: Headers = HeadersBuilder().apply {
-                            append(HttpHeaders.ContentRange, contentRange)
-                            append(HttpHeaders.AcceptRanges, "bytes")
-                        }.build()
-                        override suspend fun writeTo(channel: io.ktor.utils.io.ByteWriteChannel) {
-                            channel.writeFully(bytes)
-                        }
-                    })
-                }
+                call.respond(object : OutgoingContent.WriteChannelContent() {
+                    override val status: HttpStatusCode = HttpStatusCode.PartialContent
+                    override val contentLength: Long = length
+                    override val contentType: ContentType = entry.toContentType()
+                    override val headers: Headers = HeadersBuilder().apply {
+                        append(HttpHeaders.ContentRange, contentRange)
+                        append(HttpHeaders.AcceptRanges, "bytes")
+                    }.build()
+                    override suspend fun writeTo(channel: io.ktor.utils.io.ByteWriteChannel) {
+                        streamFileRange(fileSystem, filePath, start, length, channel)
+                    }
+                })
                 return
             }
             call.respond(object : OutgoingContent.NoContent() {
@@ -223,19 +219,42 @@ class CacheManager(
             return
         }
 
-        fileSystem.source(filePath).buffer().use { source ->
-            val bytes = source.readByteArray()
-            call.respond(object : OutgoingContent.WriteChannelContent() {
-                override val status: HttpStatusCode = HttpStatusCode.OK
-                override val contentLength: Long = bytes.size.toLong()
-                override val contentType: ContentType = entry.toContentType()
-                override val headers: Headers = HeadersBuilder().apply {
-                    append(HttpHeaders.AcceptRanges, "bytes")
-                }.build()
-                override suspend fun writeTo(channel: io.ktor.utils.io.ByteWriteChannel) {
-                    channel.writeFully(bytes)
-                }
-            })
+        call.respond(object : OutgoingContent.WriteChannelContent() {
+            override val status: HttpStatusCode = HttpStatusCode.OK
+            override val contentLength: Long = fileSize
+            override val contentType: ContentType = entry.toContentType()
+            override val headers: Headers = HeadersBuilder().apply {
+                append(HttpHeaders.AcceptRanges, "bytes")
+            }.build()
+            override suspend fun writeTo(channel: io.ktor.utils.io.ByteWriteChannel) {
+                streamFileRange(fileSystem, filePath, 0, fileSize, channel)
+            }
+        })
+    }
+
+}
+
+private const val STREAM_CHUNK_BYTES = 64 * 1024
+
+/**
+ * Copies [length] bytes from [start] in fixed-size chunks. Cached tracks are tens of MB and the
+ * player re-requests them on every seek, so they must never be read into the heap whole.
+ */
+internal suspend fun streamFileRange(
+    fileSystem: FileSystem,
+    filePath: Path,
+    start: Long,
+    length: Long,
+    channel: io.ktor.utils.io.ByteWriteChannel) {
+    fileSystem.source(filePath).buffer().use { source ->
+        source.skip(start)
+        val chunk = ByteArray(STREAM_CHUNK_BYTES)
+        var remaining = length
+        while (remaining > 0) {
+            val read = source.read(chunk, 0, minOf(chunk.size.toLong(), remaining).toInt())
+            if (read == -1) break
+            channel.writeFully(chunk, 0, read)
+            remaining -= read
         }
     }
 }

composeApp/src/commonMain/kotlin/org/spotube/spotube/core/ui/component/TrackList.kt

@@ -46,6 +46,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.layout.widthIn
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.foundation.lazy.rememberLazyListState
@@ -80,6 +81,7 @@ import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.luminance
 import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.layout.layout
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextDecoration
@@ -96,6 +98,7 @@ import org.spotube.plugin_interfaces.plugin_apis.metadata.artist.MetadataArtist
 import org.spotube.plugin_interfaces.plugin_apis.metadata.common.Thumbnail
 import org.spotube.plugin_interfaces.plugin_apis.metadata.track.MetadataTrack
 import org.spotube.spotube.core.ui.misc.SkeletonTree
+import org.spotube.spotube.core.ui.misc.uniqueLazyKeys
 import org.spotube.spotube.core.ui.misc.TextWithShimmer
 import org.spotube.spotube.core.ui.misc.shimmerApply
 import org.spotube.spotube.getPlatform
@@ -119,6 +122,42 @@ private val CompactTrackListBreakpoint = 600.dp
 private val LargeTrackListBreakpoint = 840.dp
 private const val ShimmerRowCount = 6
 
+private val TrackCardOuterPadding = 8.dp
+private val TrackCardInnerPadding = 12.dp
+private const val TrackCardTopKey = "track-card-top"
+private const val TrackCardRowKeyPrefix = "track-card-row:"
+private const val TrackCardFooterKey = "track-card-footer"
+private const val TrackCardBottomKey = "track-card-bottom"
+
+private fun Any.isTrackCardKey() = this is String && startsWith("track-card-")
+
+/**
+ * Sizes the card drawn behind a [TrackList]'s rows to the rows the list has laid out. Edges that
+ * are scrolled away are pushed a few viewports past the screen, far enough that the card's rounded
+ * corners, shadow and edge gradient stay off-screen, while the height stays bounded for huge lists.
+ */
+private fun Modifier.trackCardBounds(listState: LazyListState, edgeInsetPx: Int): Modifier =
+    layout { measurable, constraints ->
+        val info = listState.layoutInfo
+        val cardItems = info.visibleItemsInfo.filter { it.key.isTrackCardKey() }
+        if (cardItems.isEmpty()) return@layout layout(constraints.maxWidth, constraints.maxHeight) {}
+
+        // Item offsets are relative to the viewport start, which is negative by the top padding.
+        val toLocal = -info.viewportStartOffset
+        val viewport = info.viewportEndOffset - info.viewportStartOffset
+        val overscan = viewport * 3
+        val first = cardItems.first()
+        val last = cardItems.last()
+        val top = if (first.key == TrackCardTopKey) first.offset + toLocal + edgeInsetPx else -overscan
+        val bottom = if (last.key == TrackCardBottomKey) {
+            last.offset + last.size + toLocal - edgeInsetPx
+        } else viewport + overscan
+        val height = (bottom - top).coerceAtLeast(0)
+        val placeable = measurable.measure(
+            constraints.copy(minHeight = height, maxHeight = height))
+        layout(constraints.maxWidth, constraints.maxHeight) { placeable.place(0, top) }
+    }
+
 enum class TrackSortOption(val label: StringResource) {
     None(Res.string.track_list_sort_original),
     Title(Res.string.track_list_sort_title),
@@ -198,7 +237,7 @@ fun TrackList(
     val shouldLoadMore = remember(density) {
         derivedStateOf {
             val loadMoreThreshold = with(density) { 200.dp.toPx() }
-            val cardItem = listState.layoutInfo.visibleItemsInfo.find { it.key == "track-card" }
+            val cardItem = listState.layoutInfo.visibleItemsInfo.find { it.key == TrackCardBottomKey }
             // Trigger when the bottom of the track card is close to/inside the viewport,
             // which means the user has scrolled through (or is about to scroll through)
             // all loaded tracks.
@@ -219,115 +258,124 @@ fun TrackList(
     val showAlbum = !isCompact
     val useDropdownForOptions = isDesktop && !isCompact
 
+    val trackRow: @Composable (Int, MetadataTrack) -> Unit = { displayedIndex, track ->
+        TrackListRow(
+            index = displayedIndex + 1,
+            track = track,
+            showIndex = showIndex,
+            showAlbum = showAlbum,
+            useDropdownForOptions = useDropdownForOptions,
+            isCurrentTrack = track.id == currentTrackId,
+            // Only the current row depends on it, so play/pause/buffering flips don't recompose every row.
+            isCurrentTrackPlaying = isCurrentTrackPlaying && track.id == currentTrackId,
+            isSelectionMode = isSelectionMode,
+            isSelected = selectedTrackIds.contains(track.id),
+            onTrackClick = {
+                if (isSelectionMode) {
+                    selectedTrackIds =
+                        if (selectedTrackIds.contains(track.id)) {
+                            selectedTrackIds - track.id
+                        } else {
+                            selectedTrackIds + track.id
+                        }
+                } else if (isJamGuest) {
+                    onTrackOptionsAction(track, TrackOptionsAction.AddToJam)
+                } else {
+                    onTrackClick(track)
+                }
+            },
+            onLongClick = {
+                if (!useDropdownForOptions && !isSelectionMode) {
+                    isSelectionMode = true
+                    selectedTrackIds = setOf(track.id)
+                } else if (!useDropdownForOptions) {
+                    selectedTrackForOptions = track
+                }
+            },
+            onSelectionToggle = { checked ->
+                isSelectionMode = true
+                selectedTrackIds = if (checked) {
+                    selectedTrackIds + track.id
+                } else {
+                    selectedTrackIds - track.id
+                }
+            },
+            onTrackOptionsAction = { action ->
+                onTrackOptionsAction(
+                    track,
+                    action
+                )
+            },
+            trackOptionsState = trackOptionsState(track),
+            isInJam = isInJam,
+            isJamGuest = isJamGuest,
+            onShowOptionsClick = { selectedTrackForOptions = track },
+            onArtistClick = onArtistClick,
+            onAlbumClick = onAlbumClick,
+            onArtistsOverflowClick = { onArtistsOverflowClick(track) })
+    }
+
+    // Shimmer, error, empty and next-page rows at the end of the card.
+    val trackCardFooter: @Composable () -> Unit = {
+        if (isLoading && tracks.isEmpty()) {
+            repeat(ShimmerRowCount) { shimmerIndex ->
+                if (visibleTracks.isNotEmpty() || shimmerIndex > 0) {
+                    MillenniumSeparator(
+                        modifier = Modifier.padding(horizontal = 8.dp))
+                }
+                ShimmerTrackListRow(
+                    index = shimmerIndex + 1,
+                    showIndex = showIndex,
+                    showAlbum = showAlbum,
+                    useDropdownForOptions = useDropdownForOptions)
+            }
+        }
+
+        if (error != null) {
+            if (visibleTracks.isNotEmpty()) {
+                MillenniumSeparator(
+                    modifier = Modifier.padding(horizontal = 8.dp))
+            }
+            TrackListFeedbackRow(
+                message = error,
+                isError = true)
+        }
+
+        if (showEmptyMessage && !isLoading && visibleTracks.isEmpty() && error == null) {
+            TrackListFeedbackRow(stringResource(Res.string.track_list_no_tracks))
+        }
+
+        if (isLoadingNextPage) {
+            if (visibleTracks.isNotEmpty()) {
+                MillenniumSeparator(
+                    modifier = Modifier.padding(horizontal = 8.dp))
+            }
+            ShimmerTrackListRow(
+                index = visibleTracks.size + 1,
+                showIndex = showIndex,
+                showAlbum = showAlbum,
+                useDropdownForOptions = useDropdownForOptions)
+        }
+    }
+
     val trackCardContent: @Composable () -> Unit = {
         MillenniumCard(
             modifier = Modifier
                 .fillMaxWidth()
-                .padding(vertical = 8.dp),
+                .padding(vertical = TrackCardOuterPadding),
             contentPadding = PaddingValues(0.dp)) {
             Column(
                 modifier = Modifier
                     .fillMaxWidth()
-                    .padding(top = 12.dp, bottom = 12.dp)
+                    .padding(top = TrackCardInnerPadding, bottom = TrackCardInnerPadding)
             ) {
                 visibleTracks.forEachIndexed { displayedIndex, track ->
                     if (displayedIndex > 0) {
                         MillenniumSeparator()
                     }
-                    TrackListRow(
-                        index = displayedIndex + 1,
-                        track = track,
-                        showIndex = showIndex,
-                        showAlbum = showAlbum,
-                        useDropdownForOptions = useDropdownForOptions,
-                        isCurrentTrack = track.id == currentTrackId,
-                        isCurrentTrackPlaying = isCurrentTrackPlaying,
-                        isSelectionMode = isSelectionMode,
-                        isSelected = selectedTrackIds.contains(track.id),
-                        onTrackClick = {
-                            if (isSelectionMode) {
-                                selectedTrackIds =
-                                    if (selectedTrackIds.contains(track.id)) {
-                                        selectedTrackIds - track.id
-                                    } else {
-                                        selectedTrackIds + track.id
-                                    }
-                            } else if (isJamGuest) {
-                                onTrackOptionsAction(track, TrackOptionsAction.AddToJam)
-                            } else {
-                                onTrackClick(track)
-                            }
-                        },
-                        onLongClick = {
-                            if (!useDropdownForOptions && !isSelectionMode) {
-                                isSelectionMode = true
-                                selectedTrackIds = setOf(track.id)
-                            } else if (!useDropdownForOptions) {
-                                selectedTrackForOptions = track
-                            }
-                        },
-                        onSelectionToggle = { checked ->
-                            isSelectionMode = true
-                            selectedTrackIds = if (checked) {
-                                selectedTrackIds + track.id
-                            } else {
-                                selectedTrackIds - track.id
-                            }
-                        },
-                        onTrackOptionsAction = { action ->
-                            onTrackOptionsAction(
-                                track,
-                                action
-                            )
-                        },
-                        trackOptionsState = trackOptionsState(track),
-                        isInJam = isInJam,
-                        isJamGuest = isJamGuest,
-                        onShowOptionsClick = { selectedTrackForOptions = track },
-                        onArtistClick = onArtistClick,
-                        onAlbumClick = onAlbumClick,
-                        onArtistsOverflowClick = { onArtistsOverflowClick(track) })
-                }
-
-                if (isLoading && tracks.isEmpty()) {
-                    repeat(ShimmerRowCount) { shimmerIndex ->
-                        if (visibleTracks.isNotEmpty() || shimmerIndex > 0) {
-                            MillenniumSeparator(
-                                modifier = Modifier.padding(horizontal = 8.dp))
-                        }
-                        ShimmerTrackListRow(
-                            index = shimmerIndex + 1,
-                            showIndex = showIndex,
-                            showAlbum = showAlbum,
-                            useDropdownForOptions = useDropdownForOptions)
-                    }
-                }
-
-                if (error != null) {
-                    if (visibleTracks.isNotEmpty()) {
-                        MillenniumSeparator(
-                            modifier = Modifier.padding(horizontal = 8.dp))
-                    }
-                    TrackListFeedbackRow(
-                        message = error,
-                        isError = true)
-                }
-
-                if (showEmptyMessage && !isLoading && visibleTracks.isEmpty() && error == null) {
-                    TrackListFeedbackRow(stringResource(Res.string.track_list_no_tracks))
-                }
-
-                if (isLoadingNextPage) {
-                    if (visibleTracks.isNotEmpty()) {
-                        MillenniumSeparator(
-                            modifier = Modifier.padding(horizontal = 8.dp))
-                    }
-                    ShimmerTrackListRow(
-                        index = visibleTracks.size + 1,
-                        showIndex = showIndex,
-                        showAlbum = showAlbum,
-                        useDropdownForOptions = useDropdownForOptions)
+                    trackRow(displayedIndex, track)
                 }
+                trackCardFooter()
             }
         }
     }
@@ -454,29 +502,57 @@ fun TrackList(
 
     if (scrollable) {
         Box(modifier = modifier.fillMaxWidth()) {
+          Box(
+              modifier = Modifier
+                  .widthIn(max = 1280.dp)
+                  .align(Alignment.TopCenter)
+                  .padding(horizontal = if (isCompact) 6.dp else 16.dp, vertical = 8.dp)) {
+            // Rows are separate lazy items (only on-screen ones are composed, #3200), so the card
+            // they sit on is drawn once behind the list, spanning the card's laid-out items.
+            MillenniumCard(
+                modifier = Modifier
+                    .matchParentSize()
+                    .trackCardBounds(listState, with(density) { TrackCardOuterPadding.roundToPx() }),
+                contentPadding = PaddingValues(0.dp)) {}
+            // No arrangement spacing: it would also open gaps between the card's rows. The 2.dp
+            // gaps around the card are applied to the items before and after it instead.
             LazyColumn(
                 state = listState,
-                modifier = Modifier
-                    .widthIn(max = 1280.dp)
-                    .align(Alignment.TopCenter)
-                    .padding(horizontal = if (isCompact) 6.dp else 16.dp, vertical = 8.dp),
-                contentPadding = contentPadding,
-                verticalArrangement = Arrangement.spacedBy(2.dp)) {
+                contentPadding = contentPadding) {
                 if (headerContent != null) {
                     item {
-                        headerContent()
+                        Box(Modifier.padding(bottom = 2.dp)) { headerContent() }
                     }
                 }
                 if (!simplified) {
-                    item { filterSortRow() }
+                    item { Box(Modifier.padding(bottom = 2.dp)) { filterSortRow() } }
+                }
+                item(key = TrackCardTopKey) {
+                    Spacer(Modifier.fillMaxWidth().height(TrackCardOuterPadding + TrackCardInnerPadding))
+                }
+                // Plugin ids can repeat (the same track twice in a playlist).
+                val rowKeys = uniqueLazyKeys(visibleTracks) { it.id }
+                items(visibleTracks.size, key = { TrackCardRowKeyPrefix + rowKeys[it] }) { displayedIndex ->
+                    Column(Modifier.fillMaxWidth()) {
+                        if (displayedIndex > 0) {
+                            MillenniumSeparator()
+                        }
+                        trackRow(displayedIndex, visibleTracks[displayedIndex])
+                    }
+                }
+                item(key = TrackCardFooterKey) {
+                    Column(Modifier.fillMaxWidth()) { trackCardFooter() }
+                }
+                item(key = TrackCardBottomKey) {
+                    Spacer(Modifier.fillMaxWidth().height(TrackCardInnerPadding + TrackCardOuterPadding))
                 }
-                item(key = "track-card") { trackCardContent() }
                 if (footerContent != null) {
                     item {
-                        footerContent()
+                        Box(Modifier.padding(top = 2.dp)) { footerContent() }
                     }
                 }
             }
+          }
 
             if (!useDropdownForOptions) {
                 selectedTrackForOptions?.let { track ->

composeApp/src/commonMain/kotlin/org/spotube/spotube/core/ui/misc/UniqueLazyKeys.kt

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2026 Kingkor Roy Tirtho and Spotube Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.spotube.spotube.core.ui.misc
+
+import androidx.compose.foundation.lazy.LazyItemScope
+import androidx.compose.foundation.lazy.LazyListScope
+import androidx.compose.foundation.lazy.grid.LazyGridItemScope
+import androidx.compose.foundation.lazy.grid.LazyGridScope
+import androidx.compose.runtime.Composable
+
+/*
+ * Lazy lists crash when two items share a key ("Key ... was already used", #3196). Ids that come
+ * from plugins can be blank or repeat (the same playlist twice in a library page, a track added
+ * twice), so lists keyed on them use these instead of `items(list, key = { it.id })`.
+ */
+
+private const val DUPLICATE_SEPARATOR = '\u0000'
+
+/**
+ * One key per item: an item keeps its id the first time it appears, so scroll position and
+ * animations stay stable; blank ids and repeats get an occurrence suffix that can't collide with
+ * a real id.
+ */
+fun <T> uniqueLazyKeys(items: List<T>, id: (T) -> String): List<String> {
+    val occurrences = HashMap<String, Int>(items.size)
+    return items.map { item ->
+        val base = id(item)
+        val occurrence = occurrences[base] ?: 0
+        occurrences[base] = occurrence + 1
+        if (occurrence == 0 && base.isNotEmpty()) base else "$base$DUPLICATE_SEPARATOR$occurrence"
+    }
+}
+
+fun <T> LazyListScope.itemsWithUniqueKeys(
+    items: List<T>,
+    id: (T) -> String,
+    keyPrefix: String = "",
+    itemContent: @Composable LazyItemScope.(T) -> Unit
+) {
+    val keys = uniqueLazyKeys(items, id)
+    items(items.size, key = { keyPrefix + keys[it] }) { itemContent(items[it]) }
+}
+
+fun <T> LazyGridScope.itemsWithUniqueKeys(
+    items: List<T>,
+    id: (T) -> String,
+    keyPrefix: String = "",
+    itemContent: @Composable LazyGridItemScope.(T) -> Unit
+) {
+    val keys = uniqueLazyKeys(items, id)
+    items(items.size, key = { keyPrefix + keys[it] }) { itemContent(items[it]) }
+}

composeApp/src/commonMain/kotlin/org/spotube/spotube/modules/artist/ArtistScreen.kt

@@ -18,6 +18,7 @@
 package org.spotube.spotube.modules.artist
 
 
+import org.spotube.spotube.core.ui.misc.itemsWithUniqueKeys
 import org.spotube.millennium.composables.MillenniumIcon
 import org.spotube.millennium.composables.MillenniumButton
 import org.spotube.millennium.composables.MillenniumButtonStyle
@@ -638,7 +639,7 @@ private fun AlbumsSection(
         horizontalArrangement = Arrangement.spacedBy(12.dp),
         verticalAlignment = Alignment.Top
     ) {
-        items(albums, key = { it.id }) { album ->
+        itemsWithUniqueKeys(albums, id = { it.id }) { album ->
             AlbumCard(album = album)
         }
     }
@@ -676,7 +677,7 @@ private fun RelatedArtistsSection(
         horizontalArrangement = Arrangement.spacedBy(12.dp),
         verticalAlignment = Alignment.Top
     ) {
-        items(artists, key = { it.id }) { artist ->
+        itemsWithUniqueKeys(artists, id = { it.id }) { artist ->
             ArtistCard(artist = artist)
         }
     }
@@ -714,7 +715,7 @@ private fun FeaturedPlaylistsSection(
         horizontalArrangement = Arrangement.spacedBy(12.dp),
         verticalAlignment = Alignment.Top
     ) {
-        items(playlists, key = { it.id }) { playlist ->
+        itemsWithUniqueKeys(playlists, id = { it.id }) { playlist ->
             PlaylistCard(playlist = playlist)
         }
     }

composeApp/src/commonMain/kotlin/org/spotube/spotube/modules/library/LibraryMediaCollection.kt

@@ -3,6 +3,7 @@
  */
 package org.spotube.spotube.modules.library
 
+import org.spotube.spotube.core.ui.misc.itemsWithUniqueKeys
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.fillMaxSize
@@ -58,7 +59,7 @@ internal fun <T> LibraryMediaCollection(
             if (loading) items(8) { SkeletonTree(true) { skeleton(true) } }
             else {
                 if (header != null) item(key = "library_header") { header(true) }
-                items(items, key = { "media:${itemKey(it)}" }) { itemContent(it, true) }
+                itemsWithUniqueKeys(items, id = itemKey, keyPrefix = "media:") { itemContent(it, true) }
                 if (loadingMore) items(4) { SkeletonTree(true) { skeleton(true) } }
             }
         }
@@ -71,7 +72,7 @@ internal fun <T> LibraryMediaCollection(
             if (loading) items(8) { SkeletonTree(true) { skeleton(false) } }
             else {
                 if (header != null) item(key = "library_header") { header(false) }
-                items(items, key = { "media:${itemKey(it)}" }) { itemContent(it, false) }
+                itemsWithUniqueKeys(items, id = itemKey, keyPrefix = "media:") { itemContent(it, false) }
                 if (loadingMore) items(4) { SkeletonTree(true) { skeleton(false) } }
             }
         }

composeApp/src/commonMain/kotlin/org/spotube/spotube/modules/library/playlist/AddToPlaylistPicker.kt

@@ -18,6 +18,7 @@
 package org.spotube.spotube.modules.library.playlist
 
 
+import org.spotube.spotube.core.ui.misc.itemsWithUniqueKeys
 import org.spotube.spotube.core.ui.component.AdaptiveDialogBottomSheet
 import org.spotube.millennium.composables.MillenniumIcon
 import org.spotube.millennium.composables.MillenniumButton
@@ -195,7 +196,7 @@ private fun PlaylistPickerContent(
         LazyColumn(
             modifier = Modifier.fillMaxWidth(),
             verticalArrangement = Arrangement.spacedBy(4.dp)) {
-            items(playlists, key = { it.id }) { playlist ->
+            itemsWithUniqueKeys(playlists, id = { it.id }) { playlist ->
                 PlaylistPickerRow(
                     playlist = playlist,
                     onClick = { onPlaylistSelected(playlist.id) })

composeApp/src/commonMain/kotlin/org/spotube/spotube/modules/playlist/AddTracksToPlaylistDialog.kt

@@ -18,6 +18,7 @@
 package org.spotube.spotube.modules.playlist
 
 
+import org.spotube.spotube.core.ui.misc.itemsWithUniqueKeys
 import org.spotube.spotube.core.ui.component.AdaptiveDialogBottomSheet
 import org.spotube.millennium.composables.MillenniumCircularProgress
 import org.spotube.millennium.composables.MillenniumIcon
@@ -138,7 +139,7 @@ fun AddTracksToPlaylistDialog(
                             .fillMaxWidth()
                             .weight(1f),
                         verticalArrangement = Arrangement.spacedBy(4.dp)) {
-                        items(state.results, key = { it.track.id }) { result ->
+                        itemsWithUniqueKeys(state.results, id = { it.track.id }) { result ->
                             TrackSearchResultRow(
                                 track = result.track,
                                 isAdding = result.isAdding,

composeApp/src/commonMain/kotlin/org/spotube/spotube/modules/saved_tracks/SavedTracksRepository.kt

@@ -50,6 +50,14 @@ class SavedTracksRepository(
 
     val savedTracksIdsFlow : StateFlow<Set<String>> = savedTrackIds.asStateFlow()
 
+    /**
+     * Bumped only when the library itself changes (save, remove, re-login). [savedTracksIdsFlow]
+     * also grows while pages and saved-states are fetched, so reloading the list on it restarted
+     * paging on every page (#3200).
+     */
+    private val _libraryChanges = MutableStateFlow(0)
+    val libraryChanges: StateFlow<Int> = _libraryChanges.asStateFlow()
+
     init {
         scope.launch {
             pluginManager.selectedMetadataPlugin
@@ -71,6 +79,7 @@ class SavedTracksRepository(
         savedTracksCache.invalidateAll()
         totalCountCache.invalidateAll()
         savedTrackIds.value = emptySet()
+        _libraryChanges.value++
     }
 
     suspend fun getSavedTracks(paginationStrategy: PaginationStrategy? = null) =
@@ -109,6 +118,7 @@ class SavedTracksRepository(
             savedTracksCache.invalidateAll()
             totalCountCache.invalidateAll()
             savedTrackIds.value += ids.toSet()
+            _libraryChanges.value++
         }
     }
 
@@ -122,6 +132,7 @@ class SavedTracksRepository(
             savedTracksCache.invalidateAll()
             totalCountCache.invalidateAll()
             savedTrackIds.value -= ids.toSet()
+            _libraryChanges.value++
         }
     }
 

composeApp/src/commonMain/kotlin/org/spotube/spotube/modules/saved_tracks/SavedTracksViewModel.kt

@@ -152,7 +152,7 @@ class SavedTracksViewModel(
                     .filterNotNull()
                     .flatMapLatest { it.loggedInFlow }
                     .distinctUntilChanged(),
-                repository.savedTracksIdsFlow
+                repository.libraryChanges
             ) { _, _ -> }.collect {
                 loadInitialData()
                 loadCurrentUser()

composeApp/src/commonMain/kotlin/org/spotube/spotube/modules/shell/alternative_track/AlternativeTrackContent.kt

@@ -18,6 +18,7 @@
 package org.spotube.spotube.modules.shell.alternative_track
 
 
+import org.spotube.spotube.core.ui.misc.itemsWithUniqueKeys
 import org.spotube.millennium.composables.MillenniumSpokeSpinner
 import org.spotube.millennium.composables.MillenniumIcon
 import org.spotube.millennium.composables.MillenniumListTile
@@ -119,9 +120,9 @@ fun AlternativeTrackContent(
             LazyColumn(
                 modifier = Modifier.fillMaxSize(),
                 verticalArrangement = Arrangement.spacedBy(6.dp)) {
-                items(
+                itemsWithUniqueKeys(
                     items = uiState.alternatives,
-                    key = { source -> source.id }) { source ->
+                    id = { source -> source.id }) { source ->
                     AlternativeSourceRow(
                         source = source,
                         isActive = source.id == uiState.activeSourceId,

composeApp/src/commonTest/kotlin/org/spotube/spotube/core/audioplayer/DeviceAudioPlayerQueueTest.kt

@@ -8,8 +8,10 @@ import org.spotube.plugin_interfaces.plugin_apis.metadata.artist.MetadataArtist
 import org.spotube.plugin_interfaces.plugin_apis.metadata.common.Thumbnail
 import org.spotube.plugin_interfaces.plugin_apis.metadata.track.MetadataTrack
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.test.runTest
 import kotlinx.coroutines.withContext
+import kotlinx.coroutines.withTimeout
 import org.koin.core.context.startKoin
 import org.koin.core.context.stopKoin
 import org.koin.dsl.module
@@ -423,7 +425,10 @@ class DeviceAudioPlayerQueueTest {
         )
 
         val queue = createQueue()
-        withContext(Dispatchers.Default) { } // yield to let init coroutine run
+        // Restore runs on Dispatchers.IO; wait for it on real time rather than assuming one yield is enough.
+        withContext(Dispatchers.Default) {
+            withTimeout(5_000) { while (fakePlayer.loadCallCount == 0) delay(10) }
+        }
 
         assertEquals(1, fakePlayer.loadCallCount)
         assertEquals(QueueCollectionEntry.Playlist("pl-1"), queue.getCurrentCollectionEntry())

composeApp/src/jvmMain/kotlin/org/spotube/spotube/modules/library/local_tracks/media/JvmLocalMediaDiscoveryService.kt

@@ -19,6 +19,13 @@ package org.spotube.spotube.modules.library.local_tracks.media
 
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
+import org.jetbrains.skia.EncodedImageFormat
+import org.jetbrains.skia.FilterMipmap
+import org.jetbrains.skia.FilterMode
+import org.jetbrains.skia.Image
+import org.jetbrains.skia.MipmapMode
+import org.jetbrains.skia.Rect
+import org.jetbrains.skia.Surface
 import java.nio.file.FileSystems
 import java.nio.file.Files
 import java.nio.file.Path
@@ -70,7 +77,7 @@ class JvmLocalMediaDiscoveryService : LocalMediaDiscoveryService {
                                 artists = metadata?.artists?.takeIf { it.isNotEmpty() } ?: emptyList(),
                                 durationMs = metadata?.durationMs ?: 0L,
                                 album = metadata?.album,
-                                coverBytes = metadata?.coverBytes)
+                                coverBytes = metadata?.coverBytes?.let(::coverThumbnail))
                             folders.getOrPut(parent) { mutableListOf() }.add(track)
                         }
                 }
@@ -187,3 +194,30 @@ class JvmLocalMediaDiscoveryService : LocalMediaDiscoveryService {
             "wma")
     }
 }
+
+/**
+ * Embedded covers can be several MB each and the index is serialised to JSON, so keep a small
+ * JPEG like Android does (#3193). Returns null for unreadable art.
+ */
+internal fun coverThumbnail(bytes: ByteArray, size: Int = COVER_THUMBNAIL_SIZE): ByteArray? = runCatching {
+    Image.makeFromEncoded(bytes).use { source ->
+        val scale = size.toFloat() / minOf(source.width, source.height)
+        if (scale >= 1f && bytes.size <= MAX_SMALL_COVER_BYTES) return@runCatching bytes
+        val width = (source.width * scale.coerceAtMost(1f)).toInt().coerceAtLeast(1)
+        val height = (source.height * scale.coerceAtMost(1f)).toInt().coerceAtLeast(1)
+        Surface.makeRasterN32Premul(width, height).use { surface ->
+            surface.canvas.drawImageRect(
+                source,
+                Rect.makeWH(source.width.toFloat(), source.height.toFloat()),
+                Rect.makeWH(width.toFloat(), height.toFloat()),
+                FilterMipmap(FilterMode.LINEAR, MipmapMode.NONE),
+                null,
+                true)
+            surface.makeImageSnapshot().use { it.encodeToData(EncodedImageFormat.JPEG, 85)?.bytes }
+        }
+    }
+}.getOrNull()
+
+private const val COVER_THUMBNAIL_SIZE = 160
+private const val MAX_SMALL_COVER_BYTES = 64 * 1024
+

composeApp/src/jvmTest/kotlin/org/spotube/spotube/core/server/StreamFileRangeTest.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2026 Kingkor Roy Tirtho and Spotube Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.spotube.spotube.core.server
+
+import io.ktor.utils.io.ByteChannel
+import io.ktor.utils.io.readRemaining
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
+import kotlinx.io.readByteArray
+import okio.FileSystem
+import okio.Path.Companion.toOkioPath
+import java.nio.file.Files
+import kotlin.random.Random
+import kotlin.test.Test
+import kotlin.test.assertContentEquals
+
+class StreamFileRangeTest {
+    // Several chunks plus a partial one.
+    private val data = Random(42).nextBytes(64 * 1024 * 3 + 1234)
+
+    private fun copy(start: Long, length: Long): ByteArray = runBlocking {
+        val file = Files.createTempFile("spotube-cache", ".bin").also { it.toFile().deleteOnExit() }
+        Files.write(file, data)
+        val channel = ByteChannel()
+        launch {
+            streamFileRange(FileSystem.SYSTEM, file.toOkioPath(), start, length, channel)
+            channel.flushAndClose()
+        }
+        channel.readRemaining().readByteArray()
+    }
+
+    @Test
+    fun wholeFile() = assertContentEquals(data, copy(0, data.size.toLong()))
+
+    @Test
+    fun rangeAcrossChunks() {
+        val start = 70_000L
+        val length = 120_000L
+        assertContentEquals(data.copyOfRange(start.toInt(), (start + length).toInt()), copy(start, length))
+    }
+
+    @Test
+    fun lengthPastEndStopsAtEof() = assertContentEquals(data.copyOfRange(100, data.size), copy(100, data.size.toLong()))
+}

composeApp/src/jvmTest/kotlin/org/spotube/spotube/core/ui/component/TrackListVirtualizationTest.kt

@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2026 Kingkor Roy Tirtho and Spotube Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.spotube.spotube.core.ui.component
+
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.ExperimentalComposeUiApi
+import androidx.compose.ui.ImageComposeScene
+import androidx.compose.ui.semantics.SemanticsNode
+import androidx.compose.ui.semantics.SemanticsProperties
+import androidx.compose.ui.semantics.getOrNull
+import androidx.compose.ui.use
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
+import org.spotube.plugin_interfaces.plugin_apis.metadata.artist.MetadataArtist
+import org.spotube.plugin_interfaces.plugin_apis.metadata.track.MetadataTrack
+import org.spotube.spotube.core.ui.theming.SpotubeTheme
+import org.spotube.spotube.modules.settings.Theme
+import org.spotube.spotube.modules.settings.UserSettings
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+/** #3200: big track lists must only compose the rows on screen. */
+@OptIn(ExperimentalComposeUiApi::class)
+class TrackListVirtualizationTest {
+    private fun track(index: Int) = MetadataTrack(
+        // Every 100th id repeats: playlists can hold the same track twice.
+        id = if (index % 100 == 0) "dup" else "t$index",
+        title = "Song $index",
+        durationMs = 200_000L,
+        trackNumber = 1,
+        discNumber = 1,
+        artists = listOf(MetadataArtist.Basic(id = "a", name = "Artist", thumbnails = emptyList(), externalUri = null)),
+        album = null,
+        thumbnails = emptyList(),
+        explicit = false,
+        popularity = 0,
+        isrcCode = null,
+        externalUri = null)
+
+    private fun allNodes(scene: ImageComposeScene): List<SemanticsNode> {
+        fun flatten(node: SemanticsNode): List<SemanticsNode> = listOf(node) + node.children.flatMap(::flatten)
+        return scene.semanticsOwners.flatMap { flatten(it.rootSemanticsNode) }
+    }
+
+    private fun songTitles(scene: ImageComposeScene): Set<String> = allNodes(scene)
+        .flatMap { it.config.getOrNull(SemanticsProperties.Text).orEmpty() }
+        .map { it.text }
+        .filter { it.startsWith("Song ") }
+        .toSet()
+
+    @Test
+    fun onlyVisibleRowsAreComposedAndTheEndLoadsMore() {
+        val tracks = (0 until 2000).map(::track)
+        val listState = LazyListState()
+        var scope: CoroutineScope? = null
+        var nextPageRequests = 0
+
+        ImageComposeScene(1000, 800) {
+            scope = rememberCoroutineScope()
+            SpotubeTheme(UserSettings(theme = Theme.DARK)) {
+                TrackList(
+                    tracks = tracks,
+                    hasMore = true,
+                    state = listState,
+                    onLoadNextPage = { nextPageRequests++ })
+            }
+        }.use { scene ->
+            repeat(3) { scene.render().close() }
+
+            val visible = songTitles(scene)
+            assertTrue("Song 1" in visible, "first rows render: $visible")
+            assertTrue(visible.size in 3..60, "expected only on-screen rows, composed ${visible.size}")
+            assertEquals(0, nextPageRequests)
+
+            scope!!.launch { listState.scrollToItem(listState.layoutInfo.totalItemsCount - 1) }
+            repeat(3) { scene.render().close() }
+
+            val atEnd = songTitles(scene)
+            assertTrue("Song 1999" in atEnd, "last rows render: ${atEnd.sorted().takeLast(5)}")
+            assertTrue("Song 1" !in atEnd)
+            assertEquals(1, nextPageRequests)
+        }
+    }
+}

composeApp/src/jvmTest/kotlin/org/spotube/spotube/core/ui/misc/UniqueLazyKeysTest.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2026 Kingkor Roy Tirtho and Spotube Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.spotube.spotube.core.ui.misc
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class UniqueLazyKeysTest {
+    @Test
+    fun blankAndRepeatedIdsGetDistinctKeys() {
+        val ids = listOf("a", "", "b", "a", "", "a")
+        val keys = uniqueLazyKeys(ids) { it }
+
+        assertEquals(ids.size, keys.toSet().size)
+        // First occurrences keep their id so scroll position stays stable.
+        assertEquals("a", keys[0])
+        assertEquals("b", keys[2])
+    }
+
+    @Test
+    fun suffixesCannotCollideWithRealIds() {
+        val ids = listOf("a", "a", "a#1", "a1", "a_1")
+        assertEquals(ids.size, uniqueLazyKeys(ids) { it }.toSet().size)
+    }
+}

composeApp/src/jvmTest/kotlin/org/spotube/spotube/modules/library/local_tracks/media/CoverThumbnailTest.kt

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2026 Kingkor Roy Tirtho and Spotube Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.spotube.spotube.modules.library.local_tracks.media
+
+import org.jetbrains.skia.EncodedImageFormat
+import org.jetbrains.skia.Image
+import org.jetbrains.skia.Paint
+import org.jetbrains.skia.Rect
+import org.jetbrains.skia.Surface
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
+import kotlin.test.assertNull
+import kotlin.test.assertTrue
+
+class CoverThumbnailTest {
+    private fun png(width: Int, height: Int): ByteArray = Surface.makeRasterN32Premul(width, height).use { surface ->
+        // Noise-free but non-uniform so the PNG isn't trivially small.
+        for (x in 0 until width step 7) {
+            surface.canvas.drawRect(Rect.makeXYWH(x.toFloat(), 0f, 3f, height.toFloat()), Paint().apply { color = (0xFF000000.toInt() or (x * 2654435761L).toInt()) })
+        }
+        surface.makeImageSnapshot().use { it.encodeToData(EncodedImageFormat.PNG)!!.bytes }
+    }
+
+    @Test
+    fun largeCoverIsShrunkToASmallJpeg() {
+        val original = png(1600, 1200)
+        val thumbnail = assertNotNull(coverThumbnail(original))
+
+        Image.makeFromEncoded(thumbnail).use { image ->
+            assertEquals(160, minOf(image.width, image.height))
+            assertEquals(213, image.width)
+        }
+        assertTrue(thumbnail.size < 32 * 1024, "thumbnail is ${thumbnail.size} bytes")
+    }
+
+    @Test
+    fun unreadableCoverIsDropped() {
+        assertNull(coverThumbnail(byteArrayOf(1, 2, 3, 4)))
+    }
+}

gradle/libs.versions.toml

@@ -73,7 +73,7 @@ appdirs = { module = "net.harawata:appdirs", version.ref = "appdirs" }
 cache4k = { module = "io.github.reactivecircus.cache4k:cache4k", version.ref = "cache4k" }
 androidx-car-app = { module = "androidx.car.app:app", version.ref = "carApp" }
 compose-shimmer = { module = "com.valentinilk.shimmer:compose-shimmer", version.ref = "composeShimmer" }
-desugar_jdk_libs = { module = "com.android.tools:desugar_jdk_libs", version.ref = "desugar_jdk_libs" }
+desugar_jdk_libs = { module = "com.android.tools:desugar_jdk_libs_nio", version.ref = "desugar_jdk_libs" }
 dns-sd-kt = { module = "com.appstractive:dns-sd-kt", version.ref = "dnssdkt" }
 haze = { module = "dev.chrisbanes.haze:haze", version.ref = "haze" }
 haze-materials = { module = "dev.chrisbanes.haze:haze-blur-materials", version.ref = "haze" }