fix(lyrics): hold current line highlight until the next lead

lib/screens/settings/donate_page.dart

@@ -80,6 +80,8 @@ class _DonatePageState extends State<DonatePage> {
                   ],
                   _DonateLinksCard(colorScheme: colorScheme, config: _config),
                   const SizedBox(height: 16),
+                  _RecentSupportersCard(supporters: _config.supporters),
+                  const SizedBox(height: 16),
                   _DonateNoticeCard(
                     colorScheme: colorScheme,
                     notices: _config.notices,
@@ -309,6 +311,103 @@ class _DonateLinksCard extends StatelessWidget {
   }
 }
 
+class _RecentSupportersCard extends StatelessWidget {
+  const _RecentSupportersCard({required this.supporters});
+
+  final List<String> supporters;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final colorScheme = theme.colorScheme;
+    final isDark = theme.brightness == Brightness.dark;
+
+    return Card(
+      elevation: 0,
+      color: Color.alphaBlend(
+        (isDark ? Colors.white : Colors.black).withValues(
+          alpha: isDark ? 0.08 : 0.04,
+        ),
+        colorScheme.surface,
+      ),
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
+      child: Padding(
+        padding: const EdgeInsets.all(20),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Row(
+              children: [
+                Icon(Icons.star_rounded, size: 20, color: colorScheme.primary),
+                const SizedBox(width: 8),
+                Expanded(
+                  child: Text(
+                    'Recent Supporters',
+                    style: theme.textTheme.titleMedium?.copyWith(
+                      fontWeight: FontWeight.w600,
+                      color: colorScheme.onSurface,
+                    ),
+                  ),
+                ),
+              ],
+            ),
+            const SizedBox(height: 4),
+            Text(
+              'Thank you for your generosity!',
+              style: theme.textTheme.bodySmall?.copyWith(
+                color: colorScheme.onSurfaceVariant,
+              ),
+            ),
+            const SizedBox(height: 16),
+            if (supporters.isEmpty)
+              Text(
+                'No recent supporters to show.',
+                style: theme.textTheme.bodyMedium?.copyWith(
+                  color: colorScheme.onSurfaceVariant,
+                ),
+              )
+            else
+              Wrap(
+                spacing: 8,
+                runSpacing: 8,
+                children: [
+                  for (final name in supporters)
+                    Chip(
+                      backgroundColor: colorScheme.secondaryContainer,
+                      side: BorderSide.none,
+                      shape: const StadiumBorder(),
+                      avatar: CircleAvatar(
+                        backgroundColor: colorScheme.primary.withValues(
+                          alpha: 0.2,
+                        ),
+                        child: Text(
+                          name.isEmpty
+                              ? '?'
+                              : name.characters.first.toUpperCase(),
+                          style: theme.textTheme.labelSmall?.copyWith(
+                            fontWeight: FontWeight.bold,
+                            color: colorScheme.primary,
+                          ),
+                        ),
+                      ),
+                      label: Text(
+                        name,
+                        overflow: TextOverflow.ellipsis,
+                        style: theme.textTheme.labelLarge?.copyWith(
+                          color: colorScheme.onSecondaryContainer,
+                          fontWeight: FontWeight.w500,
+                        ),
+                      ),
+                    ),
+                ],
+              ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
 class _DonateNoticeCard extends StatelessWidget {
   final ColorScheme colorScheme;
   final List<String> notices;

lib/utils/lyrics_timeline.dart

@@ -58,28 +58,35 @@ class LyricDisplayLayout {
   }
 }
 
-/// Keep overlapping vocal parts lit until their explicit end. Untimed lines
-/// retain the normal single-line behavior instead of guessing a vocal length.
+/// Hold the latest lead until the next lead starts, including instrumental
+/// gaps. Earlier overlapping parts and backing vocals keep their timed ends.
 Set<int> activeLyricIndices(
   List<LyricLine> lines,
   Duration position,
   int currentIndex,
 ) {
   final active = <int>{};
+  var heldLead = -1;
   for (var i = 0; i <= currentIndex; i++) {
     final line = lines[i];
+    if (!line.isBackground &&
+        line.text.isNotEmpty &&
+        (heldLead < 0 || line.time != lines[heldLead].time)) {
+      // Simultaneous singers retain their shared first-row focus.
+      heldLead = i;
+    }
     final timedVoice =
         (i < currentIndex || line.voice != null || line.isBackground) &&
         line.text.isNotEmpty &&
         line.end != null;
-    // Known ends also apply to the most recently started singer, so a short
-    // reply does not stay lit over a longer lead vocal.
+    // Secondary simultaneous singers and backing parts keep their own ends.
     final simultaneous =
         line.text.isNotEmpty && line.time == lines[currentIndex].time;
     if (timedVoice ? line.end! > position : i == currentIndex || simultaneous) {
       active.add(i);
     }
   }
+  if (heldLead >= 0) active.add(heldLead);
   return active;
 }
 

test/lyrics_timeline_test.dart

@@ -26,7 +26,7 @@ void main() {
   });
 
   test(
-    'simultaneous timed singers retain individual ends and shared focus',
+    'simultaneous timed singers hold the primary and respect reply ends',
     () {
       final lines = LyricsParser.parse('''
 [00:01.00]v1:<00:01.00>Lead<00:05.00>
@@ -36,7 +36,7 @@ void main() {
       expect(LyricDisplayLayout(lines).focusForLine, [0, 0, 2]);
       expect(activeLyricIndices(lines, const Duration(seconds: 2), 1), {0, 1});
       expect(activeLyricIndices(lines, const Duration(seconds: 4), 1), {0});
-      expect(activeLyricIndices(lines, const Duration(seconds: 5), 1), isEmpty);
+      expect(activeLyricIndices(lines, const Duration(seconds: 5), 1), {0});
     },
   );
 
@@ -107,16 +107,43 @@ void main() {
     },
   );
 
-  test(
-    'overlapping singers stay active until their ends, including seek back',
-    () {
-      final lines = LyricsParser.parse('''
+  test('overlapping singers retain earlier ends and hold the current lead', () {
+    final lines = LyricsParser.parse('''
 [00:01.00]v1:<00:01.00>Lead<00:05.00>
 [00:02.00]v2:<00:02.00>Guest<00:04.00>
 [00:06.00]v3:Third
 ''').lines;
-      Set<int> active(int seconds) {
-        final position = Duration(seconds: seconds);
+    Set<int> active(int seconds) {
+      final position = Duration(seconds: seconds);
+      return activeLyricIndices(
+        lines,
+        position,
+        LyricsParser.activeIndex(lines, position),
+      );
+    }
+
+    expect(active(0), isEmpty);
+    expect(active(1), {0});
+    expect(active(3), {0, 1});
+    expect(active(4), {0, 1});
+    expect(active(5), {1});
+    expect(active(6), {2});
+    expect(active(3), {0, 1});
+    expect(active(1), {0});
+  });
+
+  for (final timed in [false, true]) {
+    test('holds the last vocal through a countdown and seeks ($timed)', () {
+      final lines = lyricsTimelineWithGaps(
+        LyricsParser.parse(
+          timed
+              ? '[00:01.00]v1:<00:01.00>Held<00:02.00>\n'
+                    '[00:07.00]v2:<00:07.00>Next<00:08.00>'
+              : '[00:01.00]Held\n[00:02.00]\n[00:07.00]Next',
+        ).lines,
+      );
+      Set<int> active(int milliseconds) {
+        final position = Duration(milliseconds: milliseconds);
         return activeLyricIndices(
           lines,
           position,
@@ -124,16 +151,32 @@ void main() {
         );
       }
 
+      expect(lines.map((line) => line.text), ['Held', '', 'Next']);
       expect(active(0), isEmpty);
-      expect(active(1), {0});
-      expect(active(3), {0, 1});
-      expect(active(4), {0});
-      expect(active(5), isEmpty);
-      expect(active(6), {2});
-      expect(active(3), {0, 1});
-      expect(active(1), {0});
-    },
-  );
+      expect(active(1000), {0});
+      expect(active(2000), {0, 1});
+      expect(active(6999), {0, 1});
+      expect(active(7000), {2});
+      expect(active(8000), {2});
+      expect(active(6999), {0, 1});
+      expect(active(1000), {0});
+      expect(active(0), isEmpty);
+    });
+  }
+
+  test('an ended backing part cannot replace the held lead', () {
+    final lines = lyricsTimelineWithGaps(
+      LyricsParser.parse('''
+[00:01.00]v1:<00:01.00>Lead<00:02.00>
+[bg:<00:03.00>Echo<00:04.00>]
+[00:07.00]v2:<00:07.00>Next<00:08.00>
+''').lines,
+    );
+    expect(lines.map((line) => line.text), ['Lead', 'Echo', '', 'Next']);
+    expect(activeLyricIndices(lines, const Duration(seconds: 3), 1), {0, 1});
+    expect(activeLyricIndices(lines, const Duration(seconds: 5), 2), {0, 2});
+    expect(activeLyricIndices(lines, const Duration(seconds: 7), 3), {3});
+  });
 
   List<(int, int)> gaps(String text) =>
       lyricsTimelineWithGaps(LyricsParser.parse(text).lines)

test/now_playing_lyrics_transition_test.dart

@@ -3248,7 +3248,7 @@ void main() {
             lessThan(tester.getSize(timed('Lead')).height * 0.8),
           );
           await seek(6500);
-          expect(timed('Lead'), findsNothing);
+          expect(timed('Lead'), findsOneWidget);
           expect(timed('Echo'), findsOneWidget);
           expect(offset(), closeTo(leadOffset, 0.1));
           await seek(7500);
@@ -3261,7 +3261,7 @@ void main() {
           if (mornye) {
             expect(
               tester.getTopLeft(find.text('Echo')).dy -
-                  tester.getBottomLeft(find.text('Lead')).dy,
+                  tester.getBottomLeft(timed('Lead')).dy,
               closeTo(6, 0.1),
             );
           }
@@ -3367,6 +3367,12 @@ void main() {
         expect(find.textContaining('v1:'), findsNothing);
         expect(find.textContaining('v2:'), findsNothing);
 
+        Finder timed(String text) => find.descendant(
+          of: find.byWidgetPredicate(
+            (widget) => widget is Semantics && widget.properties.label == text,
+          ),
+          matching: find.byType(CustomPaint),
+        );
         playback.add(
           PlaybackState(
             processingState: AudioProcessingState.ready,
@@ -3376,13 +3382,7 @@ void main() {
         );
         await tester.pumpAndSettle();
         for (final text in ['Lead', 'Guest']) {
-          final paint = find.descendant(
-            of: find.byWidgetPredicate(
-              (widget) =>
-                  widget is Semantics && widget.properties.label == text,
-            ),
-            matching: find.byType(CustomPaint),
-          );
+          final paint = timed(text);
           expect(
             paint,
             findsOneWidget,
@@ -3433,7 +3433,7 @@ void main() {
           ),
         );
         await tester.pumpAndSettle();
-        expect(find.text('Guest'), findsOneWidget);
+        expect(timed('Guest'), findsOneWidget);
         expect(find.text('Lead'), findsNothing);
         playback.add(
           PlaybackState(
@@ -3444,6 +3444,7 @@ void main() {
         );
         await tester.pumpAndSettle();
         expect(find.text('Lead'), findsOneWidget);
+        expect(timed('Guest'), findsOneWidget);
         expect(tester.takeException(), isNull);
       },
     );
@@ -3579,6 +3580,57 @@ void main() {
       },
     );
 
+    testWidgets('finished lyric stays bright until the next lead ($mornye)', (
+      tester,
+    ) async {
+      metadataOverrides['lyrics'] =
+          '[00:01.00]v1:<00:01.00>Held<00:02.00>\n'
+          '[00:07.00]v2:<00:07.00>Next<00:08.00>';
+      final playback = StreamController<PlaybackState>.broadcast();
+      addTearDown(playback.close);
+      await pumpNowPlaying(
+        tester,
+        theme: mornye ? MornyeTheme.build(Brightness.dark) : null,
+        size: const Size(390, 844),
+        playbackEvents: playback.stream,
+      );
+      mediaItems.add(item('first'));
+      await tester.pumpAndSettle();
+      await tester.tap(
+        mornye
+            ? find.byIcon(CupertinoIcons.quote_bubble)
+            : find.byKey(const ValueKey('material-lyrics-toggle')),
+      );
+      await tester.pumpAndSettle();
+
+      Finder timed(String text) => find.descendant(
+        of: find.byWidgetPredicate(
+          (widget) => widget is Semantics && widget.properties.label == text,
+        ),
+        matching: find.byType(CustomPaint),
+      );
+      for (final milliseconds in [1500, 2500, 6999, 7000, 8000, 6999]) {
+        playback.add(
+          PlaybackState(
+            playing: false,
+            processingState: AudioProcessingState.ready,
+            updatePosition: Duration(milliseconds: milliseconds),
+          ),
+        );
+        await tester.pumpAndSettle();
+        final text = milliseconds < 7000 ? 'Held' : 'Next';
+        expect(timed(text), findsOneWidget);
+        final opacity = tester.widget<AnimatedOpacity>(
+          find
+              .ancestor(of: timed(text), matching: find.byType(AnimatedOpacity))
+              .first,
+        );
+        expect(opacity.opacity, 1, reason: 'At $milliseconds ms');
+        expect(timed(text == 'Held' ? 'Next' : 'Held'), findsNothing);
+      }
+      expect(tester.takeException(), isNull);
+    });
+
     testWidgets(
       'original and romanization follow word timing and pauses ($mornye)',
       (tester) async {