address the code review findings

- offer a Sync button on a truly empty library tab so an empty library is not stranded (pull-to-refresh needs scrollable content)
- do not close the search field when it auto-syncs from a tab with an empty term
- make rememberArtworkColors nullable so the no-track fallbacks are live and the idle theme is the monochrome background
- measure the tab overlay content offset so the colour clip accounts for the touch-target centering
- put the pull indicator below the status-bar scrim, and seed the tab bar height estimate to avoid a first-frame inset jump
- collapse the two equal clearance constants, drop the redundant search imePadding, reuse the hoisted artwork for the mini player, and de-duplicate the mini player screenshots

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

@@ -289,7 +289,7 @@ private fun MainNavigation() {
                     MiniPlayer(
                         state = playback,
                         coverArt = miniArt,
-                        artwork = rememberArtworkColors(miniArt),
+                        artwork = artwork,
                         onExpand = { settleNowPlaying(true) },
                         onPlayPause = playbackController::togglePlayPause,
                         onNext = playbackController::next,

app/src/main/kotlin/com/subtracks/ui/components/Components.kt

@@ -172,17 +172,29 @@ fun LoadingState(modifier: Modifier = Modifier) {
 fun EmptyState(
     text: String,
     modifier: Modifier = Modifier,
+    actionLabel: String? = null,
+    onAction: (() -> Unit)? = null,
 ) {
     Box(
         modifier = modifier.fillMaxSize().padding(32.dp),
         contentAlignment = Alignment.Center,
     ) {
-        Text(
-            text = text,
-            style = MaterialTheme.typography.bodyLarge,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(16.dp),
+        ) {
+            Text(
+                text = text,
+                style = MaterialTheme.typography.bodyLarge,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                textAlign = TextAlign.Center,
+            )
+            if (actionLabel != null && onAction != null) {
+                Button(onClick = onAction) {
+                    Text(actionLabel)
+                }
+            }
+        }
     }
 }
 

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

@@ -44,6 +44,7 @@ fun AlbumsContent(
     onClearFilters: () -> Unit = {},
     resetKey: Any? = null,
     topInset: Dp = 0.dp,
+    onSync: () -> Unit = {},
     modifier: Modifier = Modifier,
 ) {
     when {
@@ -55,7 +56,12 @@ fun AlbumsContent(
             if (filtered) {
                 FilteredEmptyState(onClearFilters, modifier)
             } else {
-                EmptyState("No albums yet.\nSync with your server to fill your library.", modifier)
+                EmptyState(
+                    text = "No albums yet.\nSync with your server to fill your library.",
+                    modifier = modifier,
+                    actionLabel = "Sync",
+                    onAction = onSync,
+                )
             }
         }
 

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

@@ -42,6 +42,7 @@ fun ArtistsContent(
     onClearFilters: () -> Unit = {},
     resetKey: Any? = null,
     topInset: Dp = 0.dp,
+    onSync: () -> Unit = {},
     modifier: Modifier = Modifier,
 ) {
     when {
@@ -53,7 +54,7 @@ fun ArtistsContent(
             if (filtered) {
                 FilteredEmptyState(onClearFilters, modifier)
             } else {
-                EmptyState("No artists yet.", modifier)
+                EmptyState("No artists yet.", modifier, actionLabel = "Sync", onAction = onSync)
             }
         }
 

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

@@ -13,11 +13,11 @@ import androidx.compose.foundation.layout.WindowInsets
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.imePadding
 import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.statusBars
+import androidx.compose.foundation.layout.statusBarsPadding
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.pager.HorizontalPager
 import androidx.compose.foundation.pager.PagerState
@@ -90,6 +90,7 @@ import androidx.compose.ui.layout.boundsInParent
 import androidx.compose.ui.layout.layout
 import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.layout.onSizeChanged
+import androidx.compose.ui.layout.positionInRoot
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.semantics.clearAndSetSemantics
 import androidx.compose.ui.unit.Constraints
@@ -302,16 +303,16 @@ fun LibraryScreen(
         if (pagerState.currentPage != selectedTab.ordinal) {
             pagerState.animateScrollToPage(selectedTab.ordinal)
         }
-        searchActive = search.isNotEmpty()
+        if (search.isNotEmpty()) searchActive = true
     }
 
     val density = LocalDensity.current
     val statusBarTop = with(density) { WindowInsets.statusBars.getTop(this).toDp() }
     val filtersActive = listQuery.starred != StarredFilter.Any || search.isNotEmpty()
-    var tabBarHeightPx by remember { mutableFloatStateOf(0f) }
+    var tabBarHeightPx by remember { mutableFloatStateOf(with(density) { (TAB_BAR_CONTENT_HEIGHT + bottomInset).toPx() }) }
     val tabBarHeight = with(density) { tabBarHeightPx.toDp() }
     val listTopInset = statusBarTop
-    val listBottomInset = tabBarHeight + if (searchActive) SEARCH_BAR_CLEARANCE else FAB_CLEARANCE
+    val listBottomInset = tabBarHeight + BOTTOM_CLEARANCE
     val headerColor = artwork?.let(::playerSurfaceColor) ?: MaterialTheme.colorScheme.background
 
     Box(
@@ -335,7 +336,7 @@ fun LibraryScreen(
                     PullToRefreshDefaults.Indicator(
                         state = pullToRefreshState,
                         isRefreshing = syncing,
-                        modifier = Modifier.align(Alignment.TopCenter),
+                        modifier = Modifier.align(Alignment.TopCenter).statusBarsPadding(),
                         containerColor = headerColor,
                         color = artwork?.scheme?.primary ?: MaterialTheme.colorScheme.primary,
                     )
@@ -353,6 +354,7 @@ fun LibraryScreen(
                             onClearFilters = onClearFilters,
                             resetKey = resetKey,
                             topInset = listTopInset,
+                            onSync = onSync,
                         )
                     }
 
@@ -366,6 +368,7 @@ fun LibraryScreen(
                             onClearFilters = onClearFilters,
                             resetKey = resetKey,
                             topInset = listTopInset,
+                            onSync = onSync,
                         )
                     }
 
@@ -380,6 +383,7 @@ fun LibraryScreen(
                             onClearFilters = onClearFilters,
                             resetKey = resetKey,
                             topInset = listTopInset,
+                            onSync = onSync,
                         )
                     }
 
@@ -393,6 +397,7 @@ fun LibraryScreen(
                             onClearFilters = onClearFilters,
                             resetKey = resetKey,
                             topInset = listTopInset,
+                            onSync = onSync,
                         )
                     }
                 }
@@ -444,7 +449,6 @@ fun LibraryScreen(
                     Modifier
                         .align(Alignment.BottomCenter)
                         .fillMaxWidth()
-                        .imePadding()
                         .padding(horizontal = 12.dp, vertical = 8.dp),
             )
         }
@@ -618,8 +622,8 @@ private fun ListOptionsSheet(
     }
 }
 
-private val FAB_CLEARANCE = 80.dp
-private val SEARCH_BAR_CLEARANCE = 80.dp
+private val BOTTOM_CLEARANCE = 80.dp
+private val TAB_BAR_CONTENT_HEIGHT = 52.dp
 private val TAB_ICON_SIZE = 24.dp
 private val TAB_VERTICAL_PADDING = 6.dp
 
@@ -768,47 +772,53 @@ private fun TabButton(
     modifier: Modifier = Modifier,
 ) {
     val selectedContent = artwork?.scheme?.onPrimary ?: MaterialTheme.colorScheme.background
-    val paddingStart = with(LocalDensity.current) { 8.dp.toPx() }
     var tabLeft by remember { mutableFloatStateOf(0f) }
-    val clipStart = indicatorLeft?.minus(tabLeft + paddingStart)
-    val clipEnd = indicatorRight?.minus(tabLeft + paddingStart)
+    var tabRootX by remember { mutableFloatStateOf(0f) }
+    var contentRootX by remember { mutableFloatStateOf(0f) }
+    val contentLeft = tabLeft + (contentRootX - tabRootX)
+    val clipStart = indicatorLeft?.minus(contentLeft)
+    val clipEnd = indicatorRight?.minus(contentLeft)
     Box(
         modifier =
             modifier
-                .onGloballyPositioned { tabLeft = it.boundsInParent().left }
-                .clickable(onClick = onClick)
+                .onGloballyPositioned {
+                    tabLeft = it.boundsInParent().left
+                    tabRootX = it.positionInRoot().x
+                }.clickable(onClick = onClick)
                 .minimumInteractiveComponentSize()
                 .padding(start = 8.dp, end = 12.dp, top = TAB_VERTICAL_PADDING, bottom = TAB_VERTICAL_PADDING),
     ) {
-        if (clipStart != null && clipEnd != null) {
-            Box(
-                modifier =
-                    Modifier.drawWithContent {
-                        val hole =
-                            Path().apply {
-                                addRect(Rect(clipStart, 0f, clipEnd, size.height))
-                            }
-                        clipPath(hole, clipOp = ClipOp.Difference) {
-                            this@drawWithContent.drawContent()
-                        }
-                    },
-            ) {
-                TabContent(tab, progress, MaterialTheme.colorScheme.onBackground)
-            }
-            Box(
-                modifier =
-                    Modifier
-                        .clearAndSetSemantics {}
-                        .drawWithContent {
-                            clipRect(clipStart, 0f, clipEnd, size.height) {
+        Box(Modifier.onGloballyPositioned { contentRootX = it.positionInRoot().x }) {
+            if (clipStart != null && clipEnd != null) {
+                Box(
+                    modifier =
+                        Modifier.drawWithContent {
+                            val hole =
+                                Path().apply {
+                                    addRect(Rect(clipStart, 0f, clipEnd, size.height))
+                                }
+                            clipPath(hole, clipOp = ClipOp.Difference) {
                                 this@drawWithContent.drawContent()
                             }
                         },
-            ) {
-                TabContent(tab, progress, selectedContent)
+                ) {
+                    TabContent(tab, progress, MaterialTheme.colorScheme.onBackground)
+                }
+                Box(
+                    modifier =
+                        Modifier
+                            .clearAndSetSemantics {}
+                            .drawWithContent {
+                                clipRect(clipStart, 0f, clipEnd, size.height) {
+                                    this@drawWithContent.drawContent()
+                                }
+                            },
+                ) {
+                    TabContent(tab, progress, selectedContent)
+                }
+            } else {
+                TabContent(tab, progress, MaterialTheme.colorScheme.onBackground)
             }
-        } else {
-            TabContent(tab, progress, MaterialTheme.colorScheme.onBackground)
         }
     }
 }

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

@@ -41,6 +41,7 @@ fun PlaylistsContent(
     onClearFilters: () -> Unit = {},
     resetKey: Any? = null,
     topInset: Dp = 0.dp,
+    onSync: () -> Unit = {},
     modifier: Modifier = Modifier,
 ) {
     when {
@@ -52,7 +53,7 @@ fun PlaylistsContent(
             if (filtered) {
                 FilteredEmptyState(onClearFilters, modifier)
             } else {
-                EmptyState("No playlists yet.", modifier)
+                EmptyState("No playlists yet.", modifier, actionLabel = "Sync", onAction = onSync)
             }
         }
 

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

@@ -53,6 +53,7 @@ fun SongsContent(
     onClearFilters: () -> Unit = {},
     resetKey: Any? = null,
     topInset: Dp = 0.dp,
+    onSync: () -> Unit = {},
     modifier: Modifier = Modifier,
 ) {
     when {
@@ -64,7 +65,7 @@ fun SongsContent(
             if (filtered) {
                 FilteredEmptyState(onClearFilters, modifier)
             } else {
-                EmptyState("No songs yet.", modifier)
+                EmptyState("No songs yet.", modifier, actionLabel = "Sync", onAction = onSync)
             }
         }
 

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

@@ -182,12 +182,13 @@ private fun blendHue(
 fun rememberArtworkColors(
     ref: CoverArtRef?,
     durationMillis: Int = ARTWORK_THEME_TRANSITION_MS,
-): ArtworkColors {
+): ArtworkColors? {
     val cached = remember(ref?.cacheKey) { ref?.cacheKey?.let(ArtworkSeedCache::cached) }
     val seeds by rememberArtworkSeed(ref)
     val effective = seeds ?: cached
     val target = remember(effective) { effective?.let { (primary, secondary) -> artworkColorsFromSeeds(primary, secondary) } }
-    return rememberAnimatedArtworkColors(target, durationMillis)
+    val colors = rememberAnimatedArtworkColors(target, durationMillis)
+    return if (target == null) null else colors
 }
 
 @Composable

app/src/test/kotlin/com/subtracks/ui/AppScreenshotTest.kt

@@ -147,49 +147,18 @@ class AppScreenshotTest {
     }
 
     @Test
-    fun libraryWithMiniPlayer() {
-        composeRule.setContent {
-            SubtracksTheme {
-                val artwork = artworkColorsFromSeed(Color.rgb(120, 80, 200))
-                Column(Modifier.fillMaxSize()) {
-                    LibraryScreen(
-                        selectedTab = LibraryTab.Albums,
-                        onTabSelected = {},
-                        albums = remember { flowOf(PagingData.from(Fixtures.albums)) }.collectAsLazyPagingItems(),
-                        artists = remember { flowOf(PagingData.from(Fixtures.artists)) }.collectAsLazyPagingItems(),
-                        songs = remember { flowOf(PagingData.from(Fixtures.songItems)) }.collectAsLazyPagingItems(),
-                        playlists = remember { flowOf(PagingData.from(Fixtures.playlists)) }.collectAsLazyPagingItems(),
-                        coverArt = { id, _ -> id?.let { CoverArtRef(it, "test:$it") } },
-                        onAlbumClick = {},
-                        onArtistClick = {},
-                        onPlaylistClick = {},
-                        onSongClick = {},
-                        onSync = {},
-                        onOpenSettings = {},
-                        artwork = artwork,
-                        modifier = Modifier.weight(1f),
-                    )
-                    MiniPlayer(
-                        state = Fixtures.playbackState(),
-                        coverArt = CoverArtRef("art-al-kid-a", "test:art-al-kid-a"),
-                        artwork = artwork,
-                        onExpand = {},
-                        onPlayPause = {},
-                        onNext = {},
-                        progressInset = true,
-                    )
-                }
-            }
-        }
-        awaitTag(ALBUM_COVER_TAG)
-        composeRule.onRoot().captureRoboImage("src/test/screenshots/library_with_mini_player.png")
-    }
+    fun libraryWithMiniPlayer() = libraryWithMiniPlayerShot(Color.rgb(120, 80, 200), "library_with_mini_player.png")
 
     @Test
-    fun libraryWithMiniPlayerWarm() {
+    fun libraryWithMiniPlayerWarm() = libraryWithMiniPlayerShot(Color.rgb(222, 150, 30), "library_with_mini_player_warm.png")
+
+    private fun libraryWithMiniPlayerShot(
+        seed: Int,
+        file: String,
+    ) {
         composeRule.setContent {
             SubtracksTheme {
-                val artwork = artworkColorsFromSeed(Color.rgb(222, 150, 30))
+                val artwork = artworkColorsFromSeed(seed)
                 Column(Modifier.fillMaxSize()) {
                     LibraryScreen(
                         selectedTab = LibraryTab.Albums,
@@ -221,7 +190,7 @@ class AppScreenshotTest {
             }
         }
         awaitTag(ALBUM_COVER_TAG)
-        composeRule.onRoot().captureRoboImage("src/test/screenshots/library_with_mini_player_warm.png")
+        composeRule.onRoot().captureRoboImage("src/test/screenshots/$file")
     }
 
     @Test

app/src/test/kotlin/com/subtracks/ui/LibraryScreenTest.kt

@@ -4,11 +4,15 @@ import androidx.activity.ComponentActivity
 import androidx.compose.runtime.remember
 import androidx.compose.ui.test.junit4.v2.createAndroidComposeRule
 import androidx.compose.ui.test.onAllNodesWithTag
+import androidx.compose.ui.test.onAllNodesWithText
 import androidx.compose.ui.test.onNodeWithContentDescription
+import androidx.compose.ui.test.onNodeWithText
 import androidx.compose.ui.test.onRoot
 import androidx.compose.ui.test.performClick
 import androidx.compose.ui.test.performTouchInput
 import androidx.compose.ui.test.swipeDown
+import androidx.paging.LoadState
+import androidx.paging.LoadStates
 import androidx.paging.PagingData
 import androidx.paging.compose.collectAsLazyPagingItems
 import androidx.test.ext.junit.runners.AndroidJUnit4
@@ -72,6 +76,44 @@ class LibraryScreenTest {
         assertTrue("the settings control should open settings", settingsOpened)
     }
 
+    @Test
+    fun anEmptyTabOffersSync() {
+        var synced = false
+        composeRule.setContent {
+            SubtracksTheme {
+                LibraryScreen(
+                    selectedTab = LibraryTab.Albums,
+                    onTabSelected = {},
+                    albums = remember { flowOf(PagingData.empty<Album>(settledLoadStates)) }.collectAsLazyPagingItems(),
+                    artists = remember { flowOf(PagingData.empty<Artist>()) }.collectAsLazyPagingItems(),
+                    songs = remember { flowOf(PagingData.empty<SongListItem>()) }.collectAsLazyPagingItems(),
+                    playlists = remember { flowOf(PagingData.empty<Playlist>()) }.collectAsLazyPagingItems(),
+                    coverArt = { _, _ -> null },
+                    onAlbumClick = {},
+                    onArtistClick = {},
+                    onPlaylistClick = {},
+                    onSongClick = {},
+                    onSync = { synced = true },
+                    onOpenSettings = {},
+                )
+            }
+        }
+
+        composeRule.waitUntil(timeoutMillis = 5_000) {
+            composeRule.onAllNodesWithText("Sync").fetchSemanticsNodes().isNotEmpty()
+        }
+        composeRule.onNodeWithText("Sync").performClick()
+
+        assertTrue("an empty library should offer a sync", synced)
+    }
+
+    private val settledLoadStates =
+        LoadStates(
+            refresh = LoadState.NotLoading(endOfPaginationReached = true),
+            prepend = LoadState.NotLoading(endOfPaginationReached = true),
+            append = LoadState.NotLoading(endOfPaginationReached = true),
+        )
+
     private fun albums() =
         (1..60).map { index ->
             Album(