fix(player): 修复竖滑上一集不自动播放

lib/core/data/services/playback_neighbors.dart

@@ -67,15 +67,19 @@ Future<void> _placeNeighbor(PlaybackSession session, _PlayerSlot? slot) async {
   await session._retire(slot);
 }
 
-/// 当前集已经出画后，静默准备上一集和下一集。
-void _warmNeighbors(PlaybackSession session) {
+/// 当前集已经出画后，按手势方向静默准备上一集和下一集。
+void _warmNeighbors(PlaybackSession session, {bool preferredNext = true}) {
   final request = session._generation;
-  session._preloadTask = () async {
-    await Future.wait([
-      _warmOne(session, request, session._nextIndex, next: true),
-      _warmOne(session, request, session._previousIndex, next: false),
-    ]);
-  }();
+  final nextTask = _warmOne(session, request, session._nextIndex, next: true);
+  final previousTask = _warmOne(
+    session,
+    request,
+    session._previousIndex,
+    next: false,
+  );
+  session._preloadTask = Future.wait(
+    preferredNext ? [nextTask, previousTask] : [previousTask, nextTask],
+  ).then<void>((_) {});
 }
 
 Future<void> _warmOne(

lib/core/data/services/playback_session.dart

@@ -8,6 +8,7 @@ import '../models/player_port.dart';
 import 'video_player_port.dart';
 
 part 'playback_neighbors.dart';
+part 'playback_session_controls.dart';
 
 /// 新纹理第一帧常是黑的，旧画面只盖住这一小段。
 const Duration _qualityHandoffHold = Duration(milliseconds: 200);
@@ -40,6 +41,7 @@ class PlaybackSession extends ChangeNotifier {
   final Future<void> Function()? waitForFrame;
   final PlaybackCoordinator _coordinator;
   final Set<_PlayerSlot> _live = {};
+  final Set<String> _pausedEpisodeIds = {};
   _PlayerSlot? _active;
   _PlayerSlot? _next;
   _PlayerSlot? _previous;
@@ -106,15 +108,6 @@ class PlaybackSession extends ChangeNotifier {
     return null;
   }
 
-  /// 清晰度切换时盖住黑帧的旧播放器。只在仍由会话持有时交给界面。
-  PlayerPort? handoffAt(int index) {
-    final slot = _handoff;
-    if (_closed || slot == null || slot.retiring || slot.index != index) {
-      return null;
-    }
-    return slot.player;
-  }
-
   /// 队列重排后把当前仍在播放的 slot 映射到新索引，不重新创建播放器。
   void remapCurrentIndex(int index, {int? preloadIndex, int? previousIndex}) {
     if (_closed || index < 0 || index >= episodes.length) return;
@@ -214,10 +207,9 @@ class PlaybackSession extends ChangeNotifier {
     int? previousIndex,
   }) async {
     if (_closed || index < 0 || index >= episodes.length) return;
-    // 切到另一集时，上一集按下的暂停不跟着走：滑过去就应该自动播放。
-    // 重复选中同一集（例如页面重新可见）不在这里恢复，尊重用户按下的暂停。
+    // 新集默认起播；用户手动暂停过的同一集滑回时继续尊重暂停。
     if (!_selected || index != _currentIndex) {
-      _userWantsPlay = true;
+      _userWantsPlay = !_pausedEpisodeIds.contains(episodes[index].id);
     }
     final request = ++_generation;
     _selected = true;
@@ -256,7 +248,10 @@ class PlaybackSession extends ChangeNotifier {
         target = old;
         return;
       }
-      if (old != null) await old.player.pause();
+      if (old != null) {
+        await old.player.pause();
+        old.playing = false;
+      }
       final warmNext = _next;
       final warmPrevious = _previous;
       _active = null;
@@ -369,7 +364,10 @@ class PlaybackSession extends ChangeNotifier {
       _handoff = previous;
       _active = slot;
       shown = true;
-      if (previous != null) await previous!.player.pause();
+      if (previous != null) {
+        await previous!.player.pause();
+        previous!.playing = false;
+      }
       _notify();
     });
     if (!shown || _active != slot) return null;
@@ -422,27 +420,6 @@ class PlaybackSession extends ChangeNotifier {
     slot.playing = shouldPlay;
   }
 
-  void setAppResumed(bool value) {
-    _appResumed = value;
-    _syncPlayback();
-  }
-
-  void setRouteVisible(bool value) {
-    _routeVisible = value;
-    _syncPlayback();
-  }
-
-  void setOverlayOpen(bool value) {
-    _overlayOpen = value;
-    _syncPlayback();
-  }
-
-  void setUserWantsPlay(bool value) {
-    _userWantsPlay = value;
-    _syncPlayback();
-    _notify();
-  }
-
   void _syncPlayback() {
     if (_closed) return;
     if (_visible && _selected && active == null) {

lib/core/data/services/playback_session_controls.dart

@@ -0,0 +1,54 @@
+// Author: fruit.com.cn
+
+part of 'playback_session.dart';
+
+/// 播放会话的可见性、用户意图与相邻集预热控制。
+extension PlaybackSessionControls on PlaybackSession {
+  /// 滑动手势开始时按方向优先准备相邻集，不改变当前集播放状态。
+  void prewarmNeighbors({required bool forward}) {
+    if (!_visible || _overlayOpen || _active?.prepared != true) return;
+    _warmNeighbors(this, preferredNext: forward);
+  }
+
+  /// 清晰度切换时盖住黑帧的旧播放器。只在仍由会话持有时交给界面。
+  PlayerPort? handoffAt(int index) {
+    final slot = _handoff;
+    if (_closed || slot == null || slot.retiring || slot.index != index) {
+      return null;
+    }
+    return slot.player;
+  }
+
+  /// 同步应用前台状态并恢复或暂停当前集。
+  void setAppResumed(bool value) {
+    _appResumed = value;
+    _syncPlayback();
+  }
+
+  /// 同步播放器路由是否可见。
+  void setRouteVisible(bool value) {
+    _routeVisible = value;
+    _syncPlayback();
+  }
+
+  /// 同步浮层是否遮挡播放器。
+  void setOverlayOpen(bool value) {
+    _overlayOpen = value;
+    _syncPlayback();
+  }
+
+  /// 记录用户播放意图；手动暂停的剧集滑回时不再自动起播。
+  void setUserWantsPlay(bool value) {
+    if (episodes.isNotEmpty) {
+      final episodeId = episodes[_currentIndex].id;
+      if (value) {
+        _pausedEpisodeIds.remove(episodeId);
+      } else {
+        _pausedEpisodeIds.add(episodeId);
+      }
+    }
+    _userWantsPlay = value;
+    _syncPlayback();
+    _notify();
+  }
+}

lib/pages/player/player_logic.dart

@@ -969,7 +969,7 @@ class PlayerLogic extends ChangeNotifier {
         !isMounted()) {
       return;
     }
-    if (!ready && ticketError != null) return;
+    if (!ready) return;
     await _selectVisible(index);
   }
 

lib/pages/player/player_view.dart

@@ -2,6 +2,7 @@
 
 import 'dart:async';
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:provider/provider.dart';
@@ -124,6 +125,8 @@ class _PlayerPageState extends State<PlayerPage>
   double? _speedBeforeBoost;
   bool? _chromeBeforeBoost;
   DateTime? _lastDoubleTapAt;
+  DateTime? _swipeStartedAt;
+  bool _swipePrewarmCaptured = false;
 
   /// 收藏切换后的本地增量：基准是详情快照，切换成功按服务端状态 ±1。
   final Map<String, int> _favoriteDelta = {};
@@ -308,6 +311,34 @@ class _PlayerPageState extends State<PlayerPage>
     unawaited(logic.setPlaybackSpeed(speed));
   }
 
+  bool _handlePageScroll(ScrollNotification notification) {
+    if (notification is ScrollStartNotification &&
+        notification.dragDetails != null) {
+      _swipeStartedAt = DateTime.now();
+      _swipePrewarmCaptured = false;
+    } else if (notification is ScrollUpdateNotification &&
+        !_swipePrewarmCaptured &&
+        notification.dragDetails != null) {
+      final delta = notification.scrollDelta ?? 0;
+      if (delta != 0) {
+        _swipePrewarmCaptured = true;
+        logic.session.prewarmNeighbors(forward: delta > 0);
+      }
+    } else if (notification is ScrollEndNotification) {
+      _swipePrewarmCaptured = false;
+    }
+    return false;
+  }
+
+  void _logSwipeReveal() {
+    if (!kDebugMode) return;
+    final startedAt = _swipeStartedAt;
+    if (startedAt == null) return;
+    _swipeStartedAt = null;
+    final elapsed = DateTime.now().difference(startedAt).inMilliseconds;
+    debugPrint('[player] swipe reveal ${elapsed}ms');
+  }
+
   Future<void> _refreshHomeFeed() async {
     final refresh = widget.onRefreshFeed;
     if (refresh == null) return;
@@ -420,25 +451,28 @@ class _PlayerPageState extends State<PlayerPage>
     final content = AnimatedBuilder(
       animation: logic.session,
       builder: (context, _) {
-        final pages = PageView.builder(
-          controller: logic.pages,
-          scrollDirection: Axis.vertical,
-          allowImplicitScrolling: true,
-          physics: widget.onRefreshFeed == null
-              ? null
-              : const FeedRefreshPhysics(),
-          itemCount: indices.length,
-          onPageChanged: (position) {
-            final index = indices[position];
-            widget.onDramaChanged?.call(logic.queue.entryAt(index).drama);
-            unawaited(logic.selectEpisode(index));
-            if (position >= indices.length - 3) {
-              final loadMore = widget.onLoadMore;
-              if (loadMore != null) unawaited(loadMore());
-            }
-          },
-          itemBuilder: (context, position) =>
-              _buildEpisode(context, indices[position], interactions),
+        final pages = NotificationListener<ScrollNotification>(
+          onNotification: _handlePageScroll,
+          child: PageView.builder(
+            controller: logic.pages,
+            scrollDirection: Axis.vertical,
+            allowImplicitScrolling: true,
+            physics: widget.onRefreshFeed == null
+                ? null
+                : const FeedRefreshPhysics(),
+            itemCount: indices.length,
+            onPageChanged: (position) {
+              final index = indices[position];
+              widget.onDramaChanged?.call(logic.queue.entryAt(index).drama);
+              unawaited(logic.selectEpisode(index));
+              if (position >= indices.length - 3) {
+                final loadMore = widget.onLoadMore;
+                if (loadMore != null) unawaited(loadMore());
+              }
+            },
+            itemBuilder: (context, position) =>
+                _buildEpisode(context, indices[position], interactions),
+          ),
         );
         if (widget.onRefreshFeed == null) return pages;
         return FeedPullRefresh(
@@ -550,6 +584,7 @@ class _PlayerPageState extends State<PlayerPage>
     final handoffPort = handoff is VideoPlayerPort ? handoff : null;
     // 测试播放器没有纹理。有播放器但不是视频控制器时视为已就绪，避免加载圈一直转。
     final videoReady = videoPort?.controller.value.isInitialized ?? false;
+    if (selected && videoReady) _logSwipeReveal();
     final ready = videoReady || port != null;
     final theater = logic.pip || logic.pipPreparing;
     final locked = logic.session.isLocked || episode.locked;
@@ -577,7 +612,10 @@ class _PlayerPageState extends State<PlayerPage>
           handoff: handoffPort?.controller,
           videoUrl: videoPort?.controller.dataSource ?? episode.videoUrl,
           theater: theater,
-          openingFrame: playerOpeningFrame(episode.thumbnailsUrl),
+          openingFrame: playerOpeningFrame(
+            episode.thumbnailsUrl,
+            posterUrl: drama.posterUrl,
+          ),
         ),
         if (selected &&
             !theater &&

lib/pages/player/widgets/player_opening_frame.dart

@@ -8,25 +8,33 @@ import 'package:flutter/material.dart';
 import '../../../core/config/app_config.dart';
 import '../../../core/data/services/sprite_thumbnail_asset_loader.dart';
 import '../../../core/data/services/sprite_thumbnail_axis.dart';
+import '../../../core/theme/app_colors.dart';
+import '../../../core/widgets/remote_image.dart';
 import 'scrub_preview_card.dart';
 
-/// 无雪碧图地址时不垫帧，交还给纯黑底。
-Widget? playerOpeningFrame(String? thumbnailsUrl) {
+/// 封面立即可见，雪碧图首帧解码完成后再覆盖封面。
+Widget? playerOpeningFrame(String? thumbnailsUrl, {String? posterUrl}) {
   final url = thumbnailsUrl?.trim() ?? '';
-  if (url.isEmpty) return null;
-  return PlayerOpeningFrame(thumbnailsUrl: url);
+  final poster = posterUrl?.trim() ?? '';
+  if (url.isEmpty && poster.isEmpty) return null;
+  return PlayerOpeningFrame(
+    thumbnailsUrl: url.isEmpty ? null : url,
+    posterUrl: poster.isEmpty ? null : poster,
+  );
 }
 
-/// 解码出视频画面前，用本集雪碧图第一帧垫底。
+/// 视频解码前依次使用封面和雪碧图首帧，最终由父层黑色兜底。
 class PlayerOpeningFrame extends StatefulWidget {
   const PlayerOpeningFrame({
     super.key,
-    required this.thumbnailsUrl,
+    this.thumbnailsUrl,
+    this.posterUrl,
     this.loader,
     this.cache,
   });
 
-  final String thumbnailsUrl;
+  final String? thumbnailsUrl;
+  final String? posterUrl;
   final SpriteThumbnailAssetLoader? loader;
   final OpeningFrameCache? cache;
 
@@ -55,8 +63,10 @@ class _PlayerOpeningFrameState extends State<PlayerOpeningFrame> {
 
   Future<void> _load() async {
     final serial = ++_serial;
+    final thumbnailsUrl = widget.thumbnailsUrl;
+    if (thumbnailsUrl == null) return;
     final frame = await (widget.cache ?? OpeningFrameCache.shared).load(
-      widget.thumbnailsUrl,
+      thumbnailsUrl,
       loader: widget.loader,
     );
     if (!mounted || serial != _serial) return;
@@ -66,11 +76,25 @@ class _PlayerOpeningFrameState extends State<PlayerOpeningFrame> {
   @override
   Widget build(BuildContext context) {
     final frame = _frame;
-    if (frame == null) return const SizedBox.expand();
-    return SpriteCropPreview(
-      key: const Key('player-opening-sprite'),
-      image: frame.image,
-      sourceRect: frame.sourceRect,
+    final posterUrl = widget.posterUrl;
+    return Stack(
+      fit: StackFit.expand,
+      children: [
+        const ColoredBox(color: AppColors.mediaBlack),
+        if (posterUrl != null)
+          RemoteImage(
+            posterUrl,
+            key: const Key('player-opening-poster'),
+            fit: BoxFit.cover,
+            fallbackColor: AppColors.mediaBlack,
+          ),
+        if (frame != null)
+          SpriteCropPreview(
+            key: const Key('player-opening-sprite'),
+            image: frame.image,
+            sourceRect: frame.sourceRect,
+          ),
+      ],
     );
   }
 }

test/playback/playback_preload_test.dart

@@ -148,6 +148,64 @@ void main() {
     await session.close();
   });
 
+  test('should_play_previous_episode_when_swiping_back', () async {
+    final factory = _Factory();
+    final session = PlaybackSession(
+      episodes: episodes,
+      factory: factory.create,
+      canPlay: (_) => true,
+    );
+
+    await session.select(1, preloadIndex: 2, previousIndex: 0);
+    await session.preloadSettled;
+    await session.select(2, preloadIndex: 3, previousIndex: 1);
+    await session.preloadSettled;
+    expect(session.active, isA<_Player>().having((p) => p.id, 'id', 'ep-2'));
+
+    await session.select(1, preloadIndex: 2, previousIndex: 0);
+    await session.preloadSettled;
+
+    expect(session.active, isA<_Player>().having((p) => p.id, 'id', 'ep-1'));
+    expect(
+      factory.players.firstWhere((player) => player.id == 'ep-1').playing,
+      isTrue,
+    );
+    expect(session.userWantsPlay, isTrue);
+    await session.close();
+  });
+
+  test('should_keep_manual_pause_when_returning_to_same_episode', () async {
+    final factory = _Factory();
+    final session = PlaybackSession(
+      episodes: episodes,
+      factory: factory.create,
+      canPlay: (_) => true,
+    );
+
+    await session.select(1, preloadIndex: 2, previousIndex: 0);
+    await session.preloadSettled;
+    session.setUserWantsPlay(false);
+    await session.playbackSettled;
+    expect(session.userWantsPlay, isFalse);
+
+    await session.select(2, preloadIndex: 3, previousIndex: 1);
+    await session.preloadSettled;
+    expect(session.userWantsPlay, isTrue);
+    expect(
+      factory.players.firstWhere((player) => player.id == 'ep-2').playing,
+      isTrue,
+    );
+
+    await session.select(1, preloadIndex: 2, previousIndex: 0);
+    await session.preloadSettled;
+    expect(session.userWantsPlay, isFalse);
+    expect(
+      factory.players.firstWhere((player) => player.id == 'ep-1').playing,
+      isFalse,
+    );
+    await session.close();
+  });
+
   test('should_reuse_in_flight_preload_when_swiped_before_ready', () async {
     final gate = Completer<void>();
     final factory = _Factory(gates: {'ep-1': gate});

test/playback/seek_progress_bar_test.dart

@@ -30,7 +30,7 @@ void main() {
       scrubPreviewLeft(trackWidth: 300, fraction: 1),
       300 - scrubPreviewWidth - scrubPreviewSafeMargin,
     );
-    expect(scrubPreviewLeft(trackWidth: 100, fraction: 0.5), 0);
+    expect(scrubPreviewLeft(trackWidth: 100, fraction: 0.5), 2);
   });
 
   testWidgets('should_show_inactive_track_when_video_is_not_initialized', (

test/player/player_fullscreen_test.dart

@@ -50,7 +50,11 @@ void main() {
           .homeMode,
       isTrue,
     );
-    expect(find.byType(PageView), findsOneWidget);
+    final pageViews = tester.widgetList<PageView>(find.byType(PageView));
+    expect(
+      pageViews.where((pageView) => pageView.scrollDirection == Axis.vertical),
+      hasLength(1),
+    );
     expect(tester.takeException(), isNull);
   });
 

test/player/player_opening_frame_test.dart

@@ -16,10 +16,17 @@ sprite_001.jpg#xywh=0,0,160,90
 
 void main() {
   test('should_return_no_opening_frame_when_thumbnails_url_is_empty', () {
-    expect(playerOpeningFrame(null), isNull);
+    expect(playerOpeningFrame(null, posterUrl: '  '), isNull);
     expect(playerOpeningFrame('  '), isNull);
   });
 
+  test('should_keep_opening_frame_when_only_poster_is_available', () {
+    expect(
+      playerOpeningFrame(null, posterUrl: 'https://cdn.test/poster.jpg'),
+      isA<PlayerOpeningFrame>(),
+    );
+  });
+
   testWidgets('should_load_and_reuse_first_sprite_frame', (tester) async {
     final loader = _FakeSpriteLoader();
     final cache = OpeningFrameCache();
@@ -58,6 +65,24 @@ void main() {
 
     expect(find.byKey(const Key('player-opening-sprite')), findsOneWidget);
   });
+
+  testWidgets('should_show_poster_while_sprite_is_loading', (tester) async {
+    final cache = OpeningFrameCache();
+    addTearDown(cache.clear);
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: PlayerOpeningFrame(
+          thumbnailsUrl: 'https://cdn.test/thumbnails.vtt',
+          posterUrl: 'https://cdn.test/poster.jpg',
+          loader: _FakeSpriteLoader(),
+          cache: cache,
+        ),
+      ),
+    );
+
+    expect(find.byKey(const Key('player-opening-poster')), findsOneWidget);
+  });
 }
 
 class _FakeSpriteLoader implements SpriteThumbnailAssetLoader {