feat(lyrics): customize text size and animate active lines

test/lyrics_appearance_test.dart

@@ -0,0 +1,134 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:spotiflac_android/l10n/l10n.dart';
+import 'package:spotiflac_android/models/theme_settings.dart';
+import 'package:spotiflac_android/providers/theme_provider.dart';
+import 'package:spotiflac_android/theme/mornye_theme.dart';
+import 'package:spotiflac_android/utils/lyrics_parser.dart';
+import 'package:spotiflac_android/widgets/lyrics_size_setting.dart';
+import 'package:spotiflac_android/widgets/lyrics_text_scale.dart';
+import 'package:spotiflac_android/widgets/player_lyrics.dart';
+
+void main() {
+  setUp(() => SharedPreferences.setMockInitialValues({}));
+
+  test('lyric scaling respects accessibility and validates stored bounds', () {
+    const scale = LyricsTextScaler(TextScaler.linear(1.5), 1.2);
+    expect(scale.scale(20), 36);
+    expect(normalizeLyricsTextScale(double.nan), 1);
+    expect(normalizeLyricsTextScale(20), 1.4);
+    expect(normalizeLyricsTextScale(0), 0.8);
+    final settings = const ThemeSettings().copyWith(lyricsTextScale: 1.3);
+    expect(ThemeSettings.fromJson(settings.toJson()), settings);
+  });
+
+  testWidgets('size slider previews, persists on release and resets', (
+    tester,
+  ) async {
+    final container = ProviderContainer();
+    addTearDown(container.dispose);
+    await tester.pumpWidget(
+      UncontrolledProviderScope(
+        container: container,
+        child: MaterialApp(
+          localizationsDelegates: AppLocalizations.localizationsDelegates,
+          supportedLocales: AppLocalizations.supportedLocales,
+          home: const Scaffold(body: LyricsSizeSetting()),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+    final slider = tester.widget<Slider>(find.byType(Slider));
+    slider.onChanged!(1.3);
+    await tester.pump();
+    expect(find.text('130%'), findsOneWidget);
+    final prefs = await SharedPreferences.getInstance();
+    expect(prefs.getDouble(kLyricsTextScaleKey), isNull);
+    slider.onChangeEnd!(1.3);
+    await tester.pumpAndSettle();
+    expect(loadBootstrapThemeSettings(prefs).lyricsTextScale, 1.3);
+    await tester.tap(find.byTooltip('Reset'));
+    await tester.pumpAndSettle();
+    expect(loadBootstrapThemeSettings(prefs).lyricsTextScale, 1);
+  });
+
+  for (final reduced in [false, true]) {
+    testWidgets(
+      'Mornye subtly scales active lyrics without changing layout (reduced=$reduced)',
+      (tester) async {
+        final preview = ValueNotifier<Duration?>(const Duration(seconds: 1));
+        addTearDown(preview.dispose);
+        final theme = MornyeTheme.build(Brightness.dark);
+        await tester.pumpWidget(
+          ProviderScope(
+            child: MaterialApp(
+              theme: theme,
+              builder: (context, child) => MediaQuery(
+                data: MediaQuery.of(
+                  context,
+                ).copyWith(disableAnimations: reduced),
+                child: child!,
+              ),
+              home: Scaffold(
+                body: SyncedLyricsView(
+                  lyrics: const ParsedLyrics(
+                    synced: true,
+                    wordSynced: false,
+                    plainText: '',
+                    lines: [
+                      LyricLine(time: Duration.zero, text: 'First line'),
+                      LyricLine(
+                        time: Duration(seconds: 10),
+                        text: 'Second line',
+                      ),
+                    ],
+                  ),
+                  seekPreview: preview,
+                  colorScheme: theme.colorScheme,
+                  isActive: true,
+                  showPronunciation: false,
+                  showTranslation: false,
+                ),
+              ),
+            ),
+          ),
+        );
+        await tester.pumpAndSettle();
+        final scales = tester
+            .widgetList<AnimatedScale>(find.byType(AnimatedScale))
+            .toList();
+        expect(scales.map((widget) => widget.scale), containsAll([1.0, 0.96]));
+        expect(
+          scales.first.duration,
+          reduced ? Duration.zero : const Duration(milliseconds: 280),
+        );
+        final sizes = find
+            .byType(AnimatedScale)
+            .evaluate()
+            .map((e) => (e.renderObject! as RenderBox).size)
+            .toList();
+        preview.value = const Duration(seconds: 11);
+        await tester.pumpAndSettle();
+        expect(
+          tester
+              .widgetList<AnimatedScale>(find.byType(AnimatedScale))
+              .map((w) => w.scale)
+              .toList(),
+          scales.map((w) => w.scale).toList().reversed.toList(),
+        );
+        expect(
+          find
+              .byType(AnimatedScale)
+              .evaluate()
+              .map((e) => (e.renderObject! as RenderBox).size)
+              .toList(),
+          sizes,
+        );
+        expect(tester.takeException(), isNull);
+        await tester.pumpWidget(const SizedBox());
+      },
+    );
+  }
+}