feat(player): scroll overflowing mini player titles and artists

lib/widgets/mini_player.dart

@@ -11,6 +11,7 @@ import 'package:spotiflac_android/theme/mornye_theme.dart';
 import 'package:spotiflac_android/screens/now_playing_screen.dart';
 import 'package:spotiflac_android/utils/string_utils.dart';
 import 'package:spotiflac_android/widgets/audio_quality_badges.dart';
+import 'package:spotiflac_android/widgets/overflow_marquee.dart';
 import 'package:spotiflac_android/widgets/player_artwork.dart';
 import 'package:spotiflac_android/widgets/settings_group.dart';
 import 'package:spotiflac_android/widgets/mornye_chrome.dart';
@@ -126,35 +127,41 @@ class _MiniPlayerState extends ConsumerState<MiniPlayer> {
                           crossAxisAlignment: CrossAxisAlignment.start,
                           mainAxisSize: MainAxisSize.min,
                           children: [
-                            ExplicitTrackTitle(
-                              title: mediaItem.title,
-                              explicit:
-                                  parseExplicitFlag(
-                                    mediaItem.extras?['explicit'],
-                                  ) ==
-                                  true,
-                              style: Theme.of(context).textTheme.titleSmall
-                                  ?.copyWith(fontWeight: FontWeight.w600),
-                              maxLines: 1,
-                              overflow: TextOverflow.ellipsis,
+                            OverflowMarquee(
+                              resetKey: (mediaItem.id, mediaItem.title),
+                              child: ExplicitTrackTitle(
+                                title: mediaItem.title,
+                                explicit:
+                                    parseExplicitFlag(
+                                      mediaItem.extras?['explicit'],
+                                    ) ==
+                                    true,
+                                style: Theme.of(context).textTheme.titleSmall
+                                    ?.copyWith(fontWeight: FontWeight.w600),
+                                maxLines: 1,
+                                overflow: TextOverflow.ellipsis,
+                              ),
                             ),
-                            Text(
-                              mediaItem.artist ?? '',
-                              style: Theme.of(context).textTheme.bodySmall
-                                  ?.copyWith(
-                                    color: mornye
-                                        ? Color.lerp(
-                                            colorScheme.onSurfaceVariant,
-                                            colorScheme.onSurface,
-                                            colorScheme.brightness ==
-                                                    Brightness.dark
-                                                ? 0.7
-                                                : 0.6,
-                                          )
-                                        : colorScheme.onSurfaceVariant,
-                                  ),
-                              maxLines: 1,
-                              overflow: TextOverflow.ellipsis,
+                            OverflowMarquee(
+                              resetKey: (mediaItem.id, mediaItem.artist),
+                              child: Text(
+                                mediaItem.artist ?? '',
+                                style: Theme.of(context).textTheme.bodySmall
+                                    ?.copyWith(
+                                      color: mornye
+                                          ? Color.lerp(
+                                              colorScheme.onSurfaceVariant,
+                                              colorScheme.onSurface,
+                                              colorScheme.brightness ==
+                                                      Brightness.dark
+                                                  ? 0.7
+                                                  : 0.6,
+                                            )
+                                          : colorScheme.onSurfaceVariant,
+                                    ),
+                                maxLines: 1,
+                                overflow: TextOverflow.ellipsis,
+                              ),
                             ),
                           ],
                         ),

lib/widgets/overflow_marquee.dart

@@ -0,0 +1,146 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+
+/// Reveals overflowing content without making the mini player's text draggable.
+class OverflowMarquee extends StatefulWidget {
+  const OverflowMarquee({
+    super.key,
+    required this.resetKey,
+    required this.child,
+  });
+
+  final Object resetKey;
+  final Widget child;
+
+  @override
+  State<OverflowMarquee> createState() => _OverflowMarqueeState();
+}
+
+class _OverflowMarqueeState extends State<OverflowMarquee>
+    with WidgetsBindingObserver {
+  final _scroll = ScrollController();
+  Timer? _pause;
+  int _generation = 0;
+  bool _restartQueued = false;
+  bool _motionEnabled = false;
+  bool _appActive = true;
+  double? _viewport;
+  double? _extent;
+
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addObserver(this);
+    final lifecycle = WidgetsBinding.instance.lifecycleState;
+    _appActive = lifecycle == null || lifecycle == AppLifecycleState.resumed;
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    _motionEnabled =
+        !MediaQuery.disableAnimationsOf(context) &&
+        TickerMode.valuesOf(context).enabled;
+    _queueRestart();
+  }
+
+  @override
+  void didUpdateWidget(OverflowMarquee oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (widget.resetKey != oldWidget.resetKey) {
+      _queueRestart();
+    }
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    _appActive = state == AppLifecycleState.resumed;
+    _queueRestart();
+  }
+
+  void _queueRestart() {
+    _pause?.cancel();
+    _generation++;
+    if (_restartQueued) return;
+    _restartQueued = true;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _restartQueued = false;
+      if (!mounted || !_scroll.hasClients) return;
+      // Also cancels an in-flight animation after a track/width change.
+      _scroll.jumpTo(0);
+      if (_motionEnabled &&
+          _appActive &&
+          _scroll.position.maxScrollExtent > 0) {
+        _scheduleLeg(towardEnd: true, generation: _generation);
+      }
+    });
+    WidgetsBinding.instance.ensureVisualUpdate();
+  }
+
+  bool _canScroll(int generation) =>
+      mounted &&
+      generation == _generation &&
+      _motionEnabled &&
+      _appActive &&
+      _scroll.hasClients;
+
+  void _scheduleLeg({required bool towardEnd, required int generation}) {
+    _pause = Timer(
+      Duration(milliseconds: towardEnd ? 1500 : 1200),
+      () => _scrollLeg(towardEnd: towardEnd, generation: generation),
+    );
+  }
+
+  Future<void> _scrollLeg({
+    required bool towardEnd,
+    required int generation,
+  }) async {
+    if (!_canScroll(generation)) return;
+    final target = towardEnd ? _scroll.position.maxScrollExtent : 0.0;
+    final distance = (target - _scroll.offset).abs();
+    if (distance < 0.5) return;
+    await _scroll.animateTo(
+      target,
+      duration: Duration(milliseconds: (distance / 28 * 1000).round()),
+      curve: Curves.linear,
+    );
+    if (_canScroll(generation)) {
+      _scheduleLeg(towardEnd: !towardEnd, generation: generation);
+    }
+  }
+
+  @override
+  void dispose() {
+    WidgetsBinding.instance.removeObserver(this);
+    _pause?.cancel();
+    _scroll.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if (!_motionEnabled) return widget.child;
+
+    return NotificationListener<ScrollMetricsNotification>(
+      onNotification: (notification) {
+        final metrics = notification.metrics;
+        if (_viewport != metrics.viewportDimension ||
+            _extent != metrics.maxScrollExtent) {
+          _viewport = metrics.viewportDimension;
+          _extent = metrics.maxScrollExtent;
+          _queueRestart();
+        }
+        return false;
+      },
+      child: RepaintBoundary(
+        child: SingleChildScrollView(
+          controller: _scroll,
+          scrollDirection: Axis.horizontal,
+          physics: const NeverScrollableScrollPhysics(),
+          child: widget.child,
+        ),
+      ),
+    );
+  }
+}