feat(album): display disc groups from catalog metadata

lib/screens/album_screen.dart

@@ -36,6 +36,7 @@ import 'package:spotiflac_android/widgets/track_detail_actions.dart';
 import 'package:spotiflac_android/widgets/selection_action_button.dart';
 import 'package:spotiflac_android/widgets/selection_bottom_bar.dart';
 import 'package:spotiflac_android/widgets/downloadable_cover.dart';
+import 'package:spotiflac_android/widgets/disc_separator_chip.dart';
 import 'package:spotiflac_android/widgets/mornye_artist_header.dart';
 
 class _AlbumCache {
@@ -628,6 +629,14 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen>
     final existingHistoryKeys = ref.watch(
       downloadHistoryVisibleBatchExistsProvider(_historySnapshot.request),
     );
+    int discNumber(Track track) {
+      final number = track.discNumber ?? 1;
+      return number > 0 ? number : 1;
+    }
+
+    final hasMultipleDiscs = tracks.any(
+      (track) => discNumber(track) > 1 || (track.totalDiscs ?? 1) > 1,
+    );
     return SliverPadding(
       padding: EdgeInsets.symmetric(horizontal: wideListInset(context)),
       sliver: SliverList(
@@ -637,7 +646,7 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen>
           final isInHistory = existingHistoryKeys.contains(
             historyLookups[index].lookupKey,
           );
-          return KeyedSubtree(
+          final row = KeyedSubtree(
             key: ValueKey(selectionId),
             child: StaggeredListItem(
               index: index,
@@ -675,6 +684,18 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen>
               ),
             ),
           );
+          final disc = discNumber(track);
+          if (hasMultipleDiscs &&
+              (index == 0 || discNumber(tracks[index - 1]) != disc)) {
+            return Column(
+              crossAxisAlignment: CrossAxisAlignment.stretch,
+              children: [
+                DiscSeparatorChip(discNumber: disc),
+                row,
+              ],
+            );
+          }
+          return row;
         }, childCount: tracks.length),
       ),
     );

lib/widgets/animation_utils.dart

@@ -490,10 +490,12 @@ class _CollectionHeaderSkeleton extends StatelessWidget {
             children: [
               const SkeletonBox(width: 48, height: 48, borderRadius: 24),
               const SizedBox(width: 16),
-              SkeletonBox(
-                width: screenWidth * 0.45,
-                height: 48,
-                borderRadius: 24,
+              Flexible(
+                child: SkeletonBox(
+                  width: screenWidth * 0.45,
+                  height: 48,
+                  borderRadius: 24,
+                ),
               ),
               const SizedBox(width: 16),
               const SkeletonBox(width: 48, height: 48, borderRadius: 24),

lib/widgets/disc_separator_chip.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
+import 'package:spotiflac_android/theme/mornye_theme.dart';
 
 /// "Disc N" chip with a trailing hairline, shown between disc groups in
 /// album track lists.
@@ -11,6 +12,28 @@ class DiscSeparatorChip extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final colorScheme = Theme.of(context).colorScheme;
+    if (context.isMornye) {
+      return Padding(
+        padding: const EdgeInsets.fromLTRB(20, 20, 20, 8),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Divider(
+              height: 1,
+              color: MornyeTheme.metadataDividerColor(context),
+            ),
+            const SizedBox(height: 12),
+            Text(
+              context.l10n.downloadedAlbumDiscHeader(discNumber),
+              style: Theme.of(context).textTheme.titleSmall?.copyWith(
+                color: colorScheme.onSurfaceVariant,
+                fontWeight: FontWeight.w600,
+              ),
+            ),
+          ],
+        ),
+      );
+    }
 
     return Padding(
       padding: const EdgeInsets.fromLTRB(20, 16, 20, 8),

test/album_track_metadata_test.dart

@@ -13,6 +13,7 @@ import 'package:spotiflac_android/services/platform_bridge.dart';
 import 'package:spotiflac_android/theme/mornye_theme.dart';
 import 'package:spotiflac_android/widgets/album_description.dart';
 import 'package:spotiflac_android/widgets/audio_quality_badges.dart';
+import 'package:spotiflac_android/widgets/disc_separator_chip.dart';
 import 'package:spotiflac_android/widgets/track_list_tile.dart';
 
 void main() {
@@ -109,6 +110,84 @@ void main() {
     }
   }
 
+  for (final mornye in [false, true]) {
+    for (final discs in [1, 2]) {
+      testWidgets('online album disc groups (Mornye: $mornye, discs: $discs)', (
+        tester,
+      ) async {
+        await tester.binding.setSurfaceSize(const Size(430, 1200));
+        addTearDown(() => tester.binding.setSurfaceSize(null));
+        backendMessenger.setMockMethodCallHandler(backendChannel, (call) async {
+          if (call.method != 'getProviderMetadata') return null;
+          return jsonEncode({
+            'album_info': {'name': 'Example Album', 'total_tracks': 2},
+            'track_list': [
+              for (var index = 0; index < 2; index++)
+                {
+                  'id': 'song-$index',
+                  'name': 'Song $index',
+                  'artists': 'Example Artist',
+                  'disc_number': index == 0 ? 1 : discs,
+                  'total_discs': discs,
+                  'track_number': discs == 1 ? index + 1 : 1,
+                },
+            ],
+          });
+        });
+        await tester.pumpWidget(
+          ProviderScope(
+            child: MaterialApp(
+              theme: mornye ? MornyeTheme.build(Brightness.dark) : ThemeData(),
+              localizationsDelegates: AppLocalizations.localizationsDelegates,
+              supportedLocales: AppLocalizations.supportedLocales,
+              home: ExtensionAlbumScreen(
+                extensionId: 'example-metadata',
+                albumId: 'disc-album-$mornye-$discs',
+                albumName: 'Example Album',
+              ),
+            ),
+          ),
+        );
+        await tester.pumpAndSettle();
+        final tiles = tester.widgetList<TrackListTile>(
+          find.byType(TrackListTile),
+        );
+        expect(tiles.map((tile) => tile.track.discNumber), [1, discs]);
+        expect(tiles.map((tile) => tile.track.totalDiscs), [discs, discs]);
+        expect(
+          tiles.map((tile) => tile.track.trackNumber),
+          discs == 1 ? [1, 2] : [1, 1],
+        );
+        if (discs == 1) {
+          expect(find.byType(DiscSeparatorChip), findsNothing);
+        } else {
+          final headers = tester.widgetList<DiscSeparatorChip>(
+            find.byType(DiscSeparatorChip),
+          );
+          expect(headers.map((header) => header.discNumber), [1, 2]);
+          expect(
+            tester.getTopLeft(find.text('Disc 2')).dy,
+            inExclusiveRange(
+              tester.getBottomLeft(find.text('Song 0')).dy,
+              tester.getTopLeft(find.text('Song 1')).dy,
+            ),
+          );
+          await tester.longPress(find.text('Song 1'));
+          await tester.pumpAndSettle();
+          expect(
+            tester
+                .widgetList<TrackListTile>(find.byType(TrackListTile))
+                .map((tile) => tile.isSelected),
+            [false, true],
+          );
+        }
+        expect(tester.takeException(), isNull);
+        await tester.pumpWidget(const SizedBox());
+        await tester.pumpAndSettle();
+      });
+    }
+  }
+
   testWidgets('album tracks retain the extended tags supplied in search', (
     tester,
   ) async {