fix: Subtitle positioning issue bottom controls display (#420)

lib/models/settings/subtitle_settings_model.dart

@@ -216,7 +216,8 @@ class SubtitleText extends ConsumerWidget {
               child: Stack(
                 alignment: Alignment.bottomCenter,
                 children: [
-                  Positioned(
+                  AnimatedPositioned(
+                    duration: const Duration(milliseconds: 125),
                     bottom: position,
                     child: Container(
                       constraints: BoxConstraints(maxWidth: constraints.maxWidth, maxHeight: constraints.maxHeight),
@@ -234,7 +235,8 @@ class SubtitleText extends ConsumerWidget {
                       ),
                     ),
                   ),
-                  Positioned(
+                  AnimatedPositioned(
+                    duration: const Duration(milliseconds: 125),
                     bottom: position,
                     child: Container(
                       constraints: BoxConstraints(maxWidth: constraints.maxWidth, maxHeight: constraints.maxHeight),

lib/screens/video_player/video_player_controls.dart

@@ -41,6 +41,8 @@ class DesktopControls extends ConsumerStatefulWidget {
 }
 
 class _DesktopControlsState extends ConsumerState<DesktopControls> {
+  final GlobalKey _bottomControlsKey = GlobalKey();
+
   late RestartableTimer timer = RestartableTimer(
     const Duration(seconds: 5),
     () => mounted ? toggleOverlay(value: false) : null,
@@ -112,7 +114,7 @@ class _DesktopControlsState extends ConsumerState<DesktopControls> {
   Widget build(BuildContext context) {
     final mediaSegments = ref.watch(playBackModel.select((value) => value?.mediaSegments));
     final player = ref.watch(videoPlayerProvider);
-    final subtitleWidget = player.subtitleWidget(showOverlay);
+    final subtitleWidget = player.subtitleWidget(showOverlay, controlsKey: _bottomControlsKey);
     return InputHandler(
       autoFocus: false,
       onKeyEvent: (node, event) => _onKey(event) ? KeyEventResult.handled : KeyEventResult.ignored,
@@ -293,6 +295,7 @@ class _DesktopControlsState extends ConsumerState<DesktopControls> {
       final mediaPlayback = ref.watch(mediaPlaybackProvider);
       final bitRateOptions = ref.watch(playBackModel.select((value) => value?.bitRateOptions));
       return Container(
+        key: _bottomControlsKey, // Add key to measure height
         decoration: BoxDecoration(
             gradient: LinearGradient(
           begin: Alignment.bottomCenter,

lib/stubs/web/lib_mdk_web.dart

@@ -64,7 +64,7 @@ class LibMDK extends BasePlayer {
       null;
 
   @override
-  Widget? subtitles(bool showOverlay) => null;
+  Widget? subtitles(bool showOverlay, {GlobalKey? controlsKey}) => null;
 
   @override
   Future<void> setVolume(double volume) async {}

lib/util/subtitle_position_calculator.dart

@@ -0,0 +1,35 @@
+import 'dart:math' as math;
+
+import 'package:fladder/models/settings/subtitle_settings_model.dart';
+
+class SubtitlePositionCalculator {
+  static const double _fallbackMenuHeightPercentage = 0.15;
+  static const double _maxSubtitleOffset = 0.85;
+
+  static double calculateOffset({
+    required SubtitleSettingsModel settings,
+    required bool showOverlay,
+    required double screenHeight,
+    double? menuHeight,
+  }) {
+    if (!showOverlay) {
+      return settings.verticalOffset;
+    }
+
+    double menuHeightPercentage;
+
+    if (menuHeight != null && screenHeight > 0) {
+      menuHeightPercentage = menuHeight / screenHeight;
+    } else {
+      menuHeightPercentage = _fallbackMenuHeightPercentage;
+    }
+
+    final minSafeOffset = menuHeightPercentage;
+
+    if (settings.verticalOffset >= minSafeOffset) {
+      return math.min(settings.verticalOffset, _maxSubtitleOffset);
+    }
+
+    return math.max(0.0, math.min(minSafeOffset, _maxSubtitleOffset));
+  }
+}

lib/wrappers/media_control_wrapper.dart

@@ -39,7 +39,8 @@ class MediaControlsWrapper extends BaseAudioHandler {
   Stream<PlayerState>? get stateStream => _player?.stateStream;
   PlayerState? get lastState => _player?.lastState;
 
-  Widget? subtitleWidget(bool showOverlay) => _player?.subtitles(showOverlay);
+  Widget? subtitleWidget(bool showOverlay, {GlobalKey? controlsKey}) =>
+      _player?.subtitles(showOverlay, controlsKey: controlsKey);
   Widget? videoWidget(Key key, BoxFit fit) => _player?.videoWidget(key, fit);
 
   final Ref ref;

lib/wrappers/players/base_player.dart

@@ -19,8 +19,9 @@ abstract class BasePlayer {
     BoxFit fit,
   );
   Widget? subtitles(
-    bool showOverlay,
-  );
+    bool showOverlay, {
+    GlobalKey? controlsKey,
+  });
   Future<void> dispose();
   Future<void> open(String url, bool play);
   Future<void> seek(Duration position);

lib/wrappers/players/lib_mdk.dart

@@ -191,7 +191,7 @@ class LibMDK extends BasePlayer {
             );
 
   @override
-  Widget? subtitles(bool showOverlay) => null;
+  Widget? subtitles(bool showOverlay, {GlobalKey? controlsKey}) => null;
 
   @override
   Future<void> setVolume(double volume) async => _controller?.setVolume(volume / 100);

lib/wrappers/players/lib_mpv.dart

@@ -13,6 +13,7 @@ import 'package:fladder/models/playback/playback_model.dart';
 import 'package:fladder/models/settings/subtitle_settings_model.dart';
 import 'package:fladder/models/settings/video_player_settings.dart';
 import 'package:fladder/providers/settings/subtitle_settings_provider.dart';
+import 'package:fladder/util/subtitle_position_calculator.dart';
 import 'package:fladder/wrappers/players/base_player.dart';
 import 'package:fladder/wrappers/players/player_states.dart';
 
@@ -31,7 +32,7 @@ class LibMPV extends BasePlayer {
     dispose();
 
     mpv.MediaKit.ensureInitialized();
-    
+
     _player = mpv.Player(
       configuration: mpv.PlayerConfiguration(
         title: "nl.jknaapen.fladder",
@@ -166,12 +167,14 @@ class LibMPV extends BasePlayer {
 
   @override
   Widget? subtitles(
-    bool showOverlay,
-  ) =>
+    bool showOverlay, {
+    GlobalKey? controlsKey,
+  }) =>
       _controller != null
           ? _VideoSubtitles(
               controller: _controller!,
               showOverlay: showOverlay,
+              controlsKey: controlsKey,
             )
           : null;
 
@@ -195,27 +198,38 @@ class LibMPV extends BasePlayer {
 class _VideoSubtitles extends ConsumerStatefulWidget {
   final VideoController controller;
   final bool showOverlay;
+  final GlobalKey? controlsKey;
+
   const _VideoSubtitles({
     required this.controller,
     this.showOverlay = false,
+    this.controlsKey,
   });
 
   @override
-  ConsumerState<ConsumerStatefulWidget> createState() => _VideoSubtitlesState();
+  _VideoSubtitlesState createState() => _VideoSubtitlesState();
 }
 
 class _VideoSubtitlesState extends ConsumerState<_VideoSubtitles> {
-  late List<String> subtitle = widget.controller.player.state.subtitle;
+  late List<String> subtitle;
+  String _cachedSubtitleText = '';
+  List<String>? _lastSubtitleList;
   StreamSubscription<List<String>>? subscription;
 
+  double? _cachedMenuHeight;
+
   @override
   void initState() {
-    subscription = widget.controller.player.stream.subtitle.listen((value) {
-      setState(() {
-        subtitle = value;
-      });
-    });
     super.initState();
+    subtitle = widget.controller.player.state.subtitle;
+    subscription = widget.controller.player.stream.subtitle.listen((value) {
+      if (mounted) {
+        setState(() {
+          subtitle = value;
+          _lastSubtitleList = null;
+        });
+      }
+    });
   }
 
   @override
@@ -226,22 +240,51 @@ class _VideoSubtitlesState extends ConsumerState<_VideoSubtitles> {
 
   @override
   Widget build(BuildContext context) {
-    final settings = ref.watch(subtitleSettingsProvider);
-    final padding = MediaQuery.of(context).padding;
-    final text = [
-      for (final line in subtitle)
-        if (line.trim().isNotEmpty) line.trim(),
-    ].join('\n');
+    _measureMenuHeight();
 
-    if (widget.controller.player.platform?.configuration.libass ?? false) {
-      return const IgnorePointer(child: SizedBox.shrink());
-    } else {
-      return SubtitleText(
-        subModel: settings,
-        padding: padding,
-        offset: (widget.showOverlay ? 0.5 : settings.verticalOffset),
-        text: text,
-      );
+    final settings = ref.watch(subtitleSettingsProvider);
+    final padding = MediaQuery.paddingOf(context);
+
+    if (!const ListEquality().equals(subtitle, _lastSubtitleList)) {
+      _lastSubtitleList = List<String>.from(subtitle);
+      _cachedSubtitleText = subtitle.where((line) => line.trim().isNotEmpty).map((line) => line.trim()).join('\n');
     }
+
+    final text = _cachedSubtitleText;
+
+    final bool isLibassEnabled = widget.controller.player.platform?.configuration.libass ?? false;
+
+    if (isLibassEnabled || text.isEmpty) {
+      return const SizedBox.shrink();
+    }
+
+    final offset = SubtitlePositionCalculator.calculateOffset(
+      settings: settings,
+      showOverlay: widget.showOverlay,
+      screenHeight: MediaQuery.sizeOf(context).height,
+      menuHeight: _cachedMenuHeight,
+    );
+
+    return SubtitleText(
+      subModel: settings,
+      padding: padding,
+      offset: offset,
+      text: text,
+    );
+  }
+
+  void _measureMenuHeight() {
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted || widget.controlsKey == null) return;
+
+      final RenderBox? renderBox = widget.controlsKey?.currentContext?.findRenderObject() as RenderBox?;
+      final newHeight = renderBox?.size.height;
+
+      if (newHeight != _cachedMenuHeight && newHeight != null) {
+        setState(() {
+          _cachedMenuHeight = newHeight;
+        });
+      }
+    });
   }
 }