address the review: blank source name, synchronous title reset, shared scrim

- QueueRepository.sourceName returns null for a blank album/playlist name so the now
  playing title fallback applies instead of rendering empty
- resolve the now playing source title with remember + LaunchedEffect instead of
  produceState so it resets synchronously when the queue context changes
- extract the repeated status bar scrim into Modifier.statusBarScrim() and use it in
  AppRoot, LibraryScreen and HeroDetailScaffold

app/src/main/kotlin/com/subtracks/data/repo/QueueRepository.kt

@@ -127,9 +127,25 @@ class QueueRepository(
     ): String? {
         val library = db.libraryDao()
         return when (kind) {
-            QueueKind.Album -> library.album(sourceId, refId).first()?.name
-            QueueKind.Playlist -> library.playlist(sourceId, refId).first()?.name
-            QueueKind.Songs, QueueKind.Song -> null
+            QueueKind.Album -> {
+                library
+                    .album(sourceId, refId)
+                    .first()
+                    ?.name
+                    ?.takeIf { it.isNotBlank() }
+            }
+
+            QueueKind.Playlist -> {
+                library
+                    .playlist(sourceId, refId)
+                    .first()
+                    ?.name
+                    ?.takeIf { it.isNotBlank() }
+            }
+
+            QueueKind.Songs, QueueKind.Song -> {
+                null
+            }
         }
     }
 

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

@@ -15,7 +15,6 @@ import androidx.compose.animation.slideInHorizontally
 import androidx.compose.animation.slideInVertically
 import androidx.compose.animation.slideOutHorizontally
 import androidx.compose.animation.slideOutVertically
-import androidx.compose.foundation.background
 import androidx.compose.foundation.gestures.Orientation
 import androidx.compose.foundation.gestures.draggable
 import androidx.compose.foundation.gestures.rememberDraggableState
@@ -25,12 +24,9 @@ import androidx.compose.foundation.layout.ExperimentalLayoutApi
 import androidx.compose.foundation.layout.WindowInsets
 import androidx.compose.foundation.layout.consumeWindowInsets
 import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.imeAnimationTarget
 import androidx.compose.foundation.layout.imePadding
 import androidx.compose.foundation.layout.navigationBars
-import androidx.compose.foundation.layout.statusBars
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
@@ -44,8 +40,6 @@ import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Brush
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.layout.positionInRoot
@@ -63,6 +57,7 @@ import androidx.navigation.navArgument
 import com.subtracks.data.repo.SourceRepository
 import com.subtracks.playback.PlaybackController
 import com.subtracks.ui.components.LoadingState
+import com.subtracks.ui.components.statusBarScrim
 import com.subtracks.ui.library.AlbumDetailRoute
 import com.subtracks.ui.library.ArtistDetailRoute
 import com.subtracks.ui.library.LibraryRoute
@@ -173,7 +168,6 @@ private fun MainNavigation() {
     }
     val density = LocalDensity.current
     val navBarInset = with(density) { WindowInsets.navigationBars.getBottom(this).toDp() }
-    val statusBarInset = with(density) { WindowInsets.statusBars.getTop(this).toDp() }
     val keyboardUp = WindowInsets.imeAnimationTarget.getBottom(density) > 0
     val showMiniPlayer = playerVisible && !keyboardUp
     val bottomInset by animateDpAsState(
@@ -349,15 +343,10 @@ private fun MainNavigation() {
                     modifier =
                         Modifier
                             .align(Alignment.TopCenter)
-                            .fillMaxWidth()
-                            .height(statusBarInset + 8.dp)
+                            .statusBarScrim()
                             .graphicsLayer {
                                 alpha = ((nowPlayingProgress - SCRIM_FADE_START) / (1f - SCRIM_FADE_START)).coerceIn(0f, 1f)
-                            }.background(
-                                Brush.verticalGradient(
-                                    listOf(Color.Black.copy(alpha = 0.55f), Color.Transparent),
-                                ),
-                            ),
+                            },
                 )
             }
 

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

@@ -9,9 +9,13 @@ import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.BoxScope
 import androidx.compose.foundation.layout.BoxWithConstraints
 import androidx.compose.foundation.layout.Column
+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.padding
 import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.statusBars
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
@@ -26,7 +30,10 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.shadow
 import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
@@ -259,3 +266,16 @@ fun FilteredEmptyState(
         }
     }
 }
+
+@Composable
+fun Modifier.statusBarScrim(): Modifier {
+    val top = with(LocalDensity.current) { WindowInsets.statusBars.getTop(this).toDp() }
+    return this
+        .fillMaxWidth()
+        .height(top + 8.dp)
+        .background(
+            Brush.verticalGradient(
+                listOf(Color.Black.copy(alpha = 0.55f), Color.Transparent),
+            ),
+        )
+}

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

@@ -49,7 +49,6 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.drawBehind
-import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.layout.onGloballyPositioned
@@ -153,13 +152,8 @@ fun HeroDetailScaffold(
                 Box(
                     Modifier
                         .align(Alignment.TopStart)
-                        .fillMaxWidth()
-                        .height(statusBarDp + 8.dp)
-                        .background(
-                            Brush.verticalGradient(
-                                listOf(Color.Black.copy(alpha = 0.55f), Color.Transparent),
-                            ),
-                        ).graphicsLayer { alpha = 1f - barFraction },
+                        .statusBarScrim()
+                        .graphicsLayer { alpha = 1f - barFraction },
                 )
 
                 TopAppBar(

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

@@ -79,7 +79,6 @@ import androidx.compose.ui.geometry.CornerRadius
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.geometry.Rect
 import androidx.compose.ui.geometry.Size
-import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.ClipOp
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.Path
@@ -115,6 +114,7 @@ import com.subtracks.data.prefs.PlaylistSort
 import com.subtracks.data.prefs.SongSort
 import com.subtracks.data.prefs.StarredFilter
 import com.subtracks.playback.PlaybackController
+import com.subtracks.ui.components.statusBarScrim
 import com.subtracks.ui.theme.ArtworkColors
 import com.subtracks.ui.theme.librarySurfaceColor
 import com.subtracks.ui.theme.playerSurfaceColor
@@ -430,13 +430,7 @@ fun LibraryScreen(
             modifier =
                 Modifier
                     .align(Alignment.TopStart)
-                    .fillMaxWidth()
-                    .height(statusBarTop + 8.dp)
-                    .background(
-                        Brush.verticalGradient(
-                            listOf(Color.Black.copy(alpha = 0.55f), Color.Transparent),
-                        ),
-                    ),
+                    .statusBarScrim(),
         )
 
         if (!searchActive) {

app/src/main/kotlin/com/subtracks/ui/playback/NowPlayingScreen.kt

@@ -43,7 +43,6 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableFloatStateOf
 import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.produceState
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
@@ -91,9 +90,10 @@ fun NowPlayingRoute(
         } else {
             state.item?.album?.takeIf { it.isNotBlank() } ?: "Library"
         }
-    val sourceTitle by produceState<String>(initialValue = fallbackTitle, queueContext) {
-        value = fallbackTitle
-        value = controller.sourceTitle(queueContext) ?: fallbackTitle
+    val sourceTitle = remember(queueContext, fallbackTitle) { mutableStateOf(fallbackTitle) }
+    LaunchedEffect(queueContext, fallbackTitle) {
+        sourceTitle.value = fallbackTitle
+        sourceTitle.value = controller.sourceTitle(queueContext)?.takeIf { it.isNotBlank() } ?: fallbackTitle
     }
     LaunchedEffect(state.item?.id, state.hasNext) {
         if (!state.hasNext) return@LaunchedEffect
@@ -102,7 +102,7 @@ fun NowPlayingRoute(
     }
     NowPlayingScreen(
         state = state,
-        title = sourceTitle,
+        title = sourceTitle.value,
         coverArt = art,
         thumbnailRef = thumbnail,
         artwork = rememberArtworkColors(thumbnail ?: art),