优化：卡片上实时播放视频预览

android/settings.gradle

@@ -22,7 +22,7 @@ pluginManagement {
 plugins {
     id "dev.flutter.flutter-plugin-loader" version "1.0.0"
     id "com.android.application" version "8.9.1" apply false
-    id "org.jetbrains.kotlin.android" version "1.9.24" apply false
+    id "org.jetbrains.kotlin.android" version "2.1.0" apply false
 }
 
 include ":app"

lib/app.dart

@@ -2,6 +2,7 @@ import 'package:facebook_app_events/facebook_app_events.dart';
 import 'package:flutter/material.dart';
 
 import 'core/auth/auth_service.dart';
+import 'core/nav/app_route_observer.dart';
 import 'core/config/facebook_config.dart';
 import 'core/log/app_logger.dart';
 import 'core/theme/app_colors.dart';
@@ -12,6 +13,7 @@ import 'features/generate_video/generate_progress_screen.dart';
 import 'features/generate_video/generate_video_screen.dart';
 import 'features/gallery/models/gallery_task_item.dart';
 import 'features/generate_video/generation_result_screen.dart';
+import 'features/home/home_playback_resume.dart';
 import 'features/home/home_screen.dart';
 import 'features/home/models/task_item.dart';
 import 'features/profile/profile_screen.dart';
@@ -75,6 +77,7 @@ class _AppState extends State<App> with WidgetsBindingObserver {
           title: 'AI Video App',
           theme: AppTheme.light,
           debugShowCheckedModeBanner: false,
+          navigatorObservers: [appRouteObserver],
           initialRoute: '/',
           builder: (context, child) {
             return Stack(
@@ -141,7 +144,7 @@ class _AppState extends State<App> with WidgetsBindingObserver {
   }
 }
 
-class _MainScaffold extends StatelessWidget {
+class _MainScaffold extends StatefulWidget {
   const _MainScaffold({
     required this.currentTab,
     required this.onTabSelected,
@@ -150,20 +153,55 @@ class _MainScaffold extends StatelessWidget {
   final NavTab currentTab;
   final ValueChanged<NavTab> onTabSelected;
 
+  @override
+  State<_MainScaffold> createState() => _MainScaffoldState();
+}
+
+class _MainScaffoldState extends State<_MainScaffold> with RouteAware {
+  bool _routeObserverSubscribed = false;
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    if (!_routeObserverSubscribed) {
+      final route = ModalRoute.of(context);
+      if (route is PageRoute<dynamic>) {
+        appRouteObserver.subscribe(this, route);
+        _routeObserverSubscribed = true;
+      }
+    }
+  }
+
+  @override
+  void dispose() {
+    if (_routeObserverSubscribed) {
+      appRouteObserver.unsubscribe(this);
+    }
+    super.dispose();
+  }
+
+  /// 挂在 `/` 的 [PageRoute] 上：任意子页面 pop 后底层重新露出时触发（比 [HomeScreen] 内订阅更可靠）
+  @override
+  void didPopNext() {
+    if (widget.currentTab == NavTab.home) {
+      homePlaybackResumeNonce.value++;
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
       body: IndexedStack(
-        index: currentTab.index,
+        index: widget.currentTab.index,
         children: [
-          HomeScreen(isActive: currentTab == NavTab.home),
+          HomeScreen(isActive: widget.currentTab == NavTab.home),
-          GalleryScreen(isActive: currentTab == NavTab.gallery),
+          GalleryScreen(isActive: widget.currentTab == NavTab.gallery),
-          ProfileScreen(isActive: currentTab == NavTab.profile),
+          ProfileScreen(isActive: widget.currentTab == NavTab.profile),
         ],
       ),
       bottomNavigationBar: BottomNavBar(
-        currentTab: currentTab,
+        currentTab: widget.currentTab,
-        onTabSelected: onTabSelected,
+        onTabSelected: widget.onTabSelected,
       ),
     );
   }

lib/core/nav/app_route_observer.dart

@@ -0,0 +1,5 @@
+import 'package:flutter/material.dart';
+
+/// 用于 [RouteAware]（例如首页从 push 的全屏页返回时刷新可见区域）
+final RouteObserver<PageRoute<dynamic>> appRouteObserver =
+    RouteObserver<PageRoute<dynamic>>();

lib/features/home/home_playback_resume.dart

@@ -0,0 +1,4 @@
+import 'package:flutter/foundation.dart';
+
+/// 子路由从 Navigator pop 回主导航后，通知首页刷新 [VisibilityDetector]（见 [_MainScaffoldState.didPopNext]）
+final ValueNotifier<int> homePlaybackResumeNonce = ValueNotifier<int>(0);

lib/features/home/home_screen.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:visibility_detector/visibility_detector.dart';
 
 import '../../core/api/services/image_api.dart';
 import '../../core/auth/auth_service.dart';
@@ -10,6 +11,7 @@ import 'models/category_item.dart';
 import 'models/ext_config_item.dart';
 import 'models/task_item.dart';
 import 'widgets/home_tab_row.dart';
+import 'home_playback_resume.dart';
 import 'widgets/video_card.dart';
 
 /// 固定「pets」分类 id，用于展示 extConfig.items
@@ -31,7 +33,23 @@ class _HomeScreenState extends State<HomeScreen> {
   List<TaskItem> _tasks = [];
   bool _categoriesLoading = true;
   bool _tasksLoading = false;
-  int? _activeCardIndex;
+  /// 当前在屏幕上有足够可见比例、且带有预览视频的格子（由 [VisibilityDetector] 实测，允许多个）
+  Set<int> _visibleVideoIndices = {};
+  /// 用户在本轮可视周期内点过「停止」的索引；滑出视口后清除，再次进入可自动播放
+  final Set<int> _userPausedVideoIndices = {};
+  final ScrollController _scrollController = ScrollController();
+  /// [index] -> 最近一次 visibility 回调的 [VisibilityInfo.visibleFraction]
+  final Map<int, double> _cardVisibleFraction = {};
+  bool _visibilityReconcileScheduled = false;
+
+  /// IndexedStack 切回首页或 [homePlaybackResumeNonce] 递增后，立即让 [VisibilityDetector] 重新计算
+  void _scheduleVisibilityRefresh() {
+    if (!widget.isActive) return;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted || !widget.isActive) return;
+      VisibilityDetectorController.instance.notifyNow();
+    });
+  }
 
   @override
   void initState() {
@@ -40,19 +58,27 @@ class _HomeScreenState extends State<HomeScreen> {
     UserState.extConfigItems.addListener(_onExtConfigChanged);
     AuthService.isLoginComplete.addListener(_onExtConfigChanged);
     UserState.homeReloadNonce.addListener(_onHomeReloadNonce);
+    homePlaybackResumeNonce.addListener(_onHomePlaybackResumeSignal);
     _loadCategories();
     if (widget.isActive) refreshAccount();
   }
 
   @override
   void dispose() {
+    homePlaybackResumeNonce.removeListener(_onHomePlaybackResumeSignal);
     UserState.needShowVideoMenu.removeListener(_onExtConfigChanged);
     UserState.extConfigItems.removeListener(_onExtConfigChanged);
     AuthService.isLoginComplete.removeListener(_onExtConfigChanged);
     UserState.homeReloadNonce.removeListener(_onHomeReloadNonce);
+    _scrollController.dispose();
     super.dispose();
   }
 
+  void _onHomePlaybackResumeSignal() {
+    if (!mounted || !widget.isActive) return;
+    _scheduleVisibilityRefresh();
+  }
+
   void _onExtConfigChanged() {
     if (mounted) setState(() {});
   }
@@ -62,11 +88,55 @@ class _HomeScreenState extends State<HomeScreen> {
     _loadCategories();
   }
 
+  static const double _videoVisibilityThreshold = 0.15;
+
+  void _onGridCardVisibilityChanged(int index, VisibilityInfo info) {
+    if (!mounted) return;
+    if (info.visibleFraction >= _videoVisibilityThreshold) {
+      _cardVisibleFraction[index] = info.visibleFraction;
+    } else {
+      _cardVisibleFraction.remove(index);
+    }
+    if (_visibilityReconcileScheduled) return;
+    _visibilityReconcileScheduled = true;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _visibilityReconcileScheduled = false;
+      if (mounted) _reconcileVisibleVideoIndicesFromDetector();
+    });
+  }
+
+  void _reconcileVisibleVideoIndicesFromDetector() {
+    final tasks = _displayTasks;
+    final next = <int>{};
+    for (final e in _cardVisibleFraction.entries) {
+      final i = e.key;
+      if (i < 0 || i >= tasks.length) continue;
+      if (e.value < _videoVisibilityThreshold) continue;
+      final url = tasks[i].previewVideoUrl;
+      if (url != null && url.isNotEmpty) {
+        next.add(i);
+      }
+    }
+    _userPausedVideoIndices.removeWhere((i) => !next.contains(i));
+    if (!_setsEqual(next, _visibleVideoIndices)) {
+      setState(() => _visibleVideoIndices = next);
+    }
+  }
+
+  bool _setsEqual(Set<int> a, Set<int> b) {
+    if (a.length != b.length) return false;
+    for (final e in a) {
+      if (!b.contains(e)) return false;
+    }
+    return true;
+  }
+
   @override
   void didUpdateWidget(covariant HomeScreen oldWidget) {
     super.didUpdateWidget(oldWidget);
     if (widget.isActive && !oldWidget.isActive) {
       refreshAccount();
+      _scheduleVisibilityRefresh();
     }
   }
 
@@ -119,7 +189,8 @@ class _HomeScreenState extends State<HomeScreen> {
               templateName: e.title,
               title: e.title,
               previewImageUrl: e.image,
-              previewVideoUrl: null,
+              // 尝试从 detail 字段中提取视频 URL（如果有）
+              previewVideoUrl: null, // 暂时保持为 null，需要根据实际数据结构调整
               taskType: e.title,
               ext: e.detail,
               credits480p: e.cost,
@@ -128,6 +199,7 @@ class _HomeScreenState extends State<HomeScreen> {
   }
 
   Future<void> _loadCategories() async {
+    print('HomeScreen: _loadCategories called');
     setState(() => _categoriesLoading = true);
     await AuthService.loginComplete;
     if (!mounted) return;
@@ -137,23 +209,29 @@ class _HomeScreenState extends State<HomeScreen> {
         final list = (res.data as List)
             .map((e) => CategoryItem.fromJson(e as Map<String, dynamic>))
             .toList();
+        print('HomeScreen: Categories loaded: ${list.length} items');
         if (UserState.needShowVideoMenu.value == true) {
           list.add(const CategoryItem(id: kExtCategoryId, name: 'pets', icon: null));
+          print('HomeScreen: Added pets category');
         }
         setState(() {
           _categories = list;
           _selectedCategory = list.isNotEmpty ? list.first : null;
+          print('HomeScreen: Selected category: ${_selectedCategory?.name}');
           if (_selectedCategory != null) {
             if (_selectedCategory!.id == kExtCategoryId) {
               _tasks = [];
               _tasksLoading = false;
+              print('HomeScreen: Selected pets category, tasks cleared');
             } else {
+              print('HomeScreen: Loading tasks for category: ${_selectedCategory!.id}');
               _loadTasks(_selectedCategory!.id);
             }
           }
         });
       } else {
         setState(() => _categories = []);
+        print('HomeScreen: Failed to load categories');
       }
       setState(() => _categoriesLoading = false);
     }
@@ -169,10 +247,17 @@ class _HomeScreenState extends State<HomeScreen> {
             .toList();
         setState(() {
           _tasks = list;
-          _activeCardIndex = null;
+          _userPausedVideoIndices.clear();
+          _visibleVideoIndices = {};
+          _cardVisibleFraction.clear();
         });
       } else {
-        setState(() => _tasks = []);
+        setState(() {
+          _tasks = [];
+          _userPausedVideoIndices.clear();
+          _visibleVideoIndices = {};
+          _cardVisibleFraction.clear();
+        });
       }
       setState(() => _tasksLoading = false);
     }
@@ -184,6 +269,9 @@ class _HomeScreenState extends State<HomeScreen> {
       setState(() {
         _tasks = [];
         _tasksLoading = false;
+        _userPausedVideoIndices.clear();
+        _visibleVideoIndices = {};
+        _cardVisibleFraction.clear();
       });
     } else {
       _loadTasks(c.id);
@@ -240,6 +328,7 @@ class _HomeScreenState extends State<HomeScreen> {
                               AppSpacing.screenPadding,
                               AppSpacing.screenPaddingLarge,
                             ),
+                            controller: _scrollController,
                             gridDelegate:
                                 const SliverGridDelegateWithFixedCrossAxisCount(
                               crossAxisCount: 2,
@@ -253,21 +342,32 @@ class _HomeScreenState extends State<HomeScreen> {
                               final credits = task.credits480p != null
                                   ? task.credits480p.toString()
                                   : '50';
-                              return VideoCard(
+                              final detectorKey =
-                                imageUrl:
+                                  'home_card_${index}_${task.previewVideoUrl ?? ''}_${task.title}';
-                                    task.previewImageUrl ?? _placeholderImage,
+                              return VisibilityDetector(
+                                key: ValueKey(detectorKey),
+                                onVisibilityChanged: (info) =>
+                                    _onGridCardVisibilityChanged(index, info),
+                                child: VideoCard(
+                                  key: ValueKey(detectorKey),
+                                  imageUrl: task.previewImageUrl ??
+                                      _placeholderImage,
                                   videoUrl: task.previewVideoUrl,
                                   credits: credits,
-                                isActive: _activeCardIndex == index,
+                                  isActive:
-                                onPlayRequested: () =>
+                                      _visibleVideoIndices.contains(index) &&
-                                    setState(() => _activeCardIndex = index),
+                                          !_userPausedVideoIndices
-                                onStopRequested: () =>
+                                              .contains(index),
-                                    setState(() => _activeCardIndex = null),
+                                  onPlayRequested: () => setState(() =>
+                                      _userPausedVideoIndices.remove(index)),
+                                  onStopRequested: () => setState(() =>
+                                      _userPausedVideoIndices.add(index)),
                                   onGenerateSimilar: () =>
                                       Navigator.of(context).pushNamed(
                                     '/generate',
                                     arguments: task,
                                   ),
+                                ),
                               );
                             },
                           ),

lib/features/home/widgets/video_card.dart

@@ -1,13 +1,16 @@
+import 'dart:io' show File;
+
 import 'package:flutter/material.dart';
-import 'package:flutter_cache_manager/flutter_cache_manager.dart';
+import 'package:flutter_cache_manager/flutter_cache_manager.dart'
+    show DefaultCacheManager, DownloadProgress, FileInfo;
 import 'package:flutter_lucide/flutter_lucide.dart';
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:video_player/video_player.dart';
 
 import '../../../core/theme/app_colors.dart';
 
-/// Video card for home grid - 点击播放按钮可在卡片上播放视频
+/// Video card for home grid：在 [isActive] 为 true 时自动静音循环播放 [videoUrl]；
-/// 同时只能一个卡片处于播放状态
+/// 父组件按视口控制多个卡片可同时处于播放状态。
 class VideoCard extends StatefulWidget {
   const VideoCard({
     super.key,
@@ -34,6 +37,12 @@ class VideoCard extends StatefulWidget {
 
 class _VideoCardState extends State<VideoCard> {
   VideoPlayerController? _controller;
+  /// 递增以作废过期的异步 [ _loadAndPlay ]，避免多路初始化互相抢同一个 State
+  int _loadGen = 0;
+  /// 从网络拉取视频时显示底部细进度条（缓存命中则不会出现）
+  bool _showBottomProgress = false;
+  /// 0–1 为确定进度；null 为不确定（无 Content-Length 等）
+  double? _bottomProgressFraction;
 
   @override
   void initState() {
@@ -71,66 +80,116 @@ class _VideoCardState extends State<VideoCard> {
     _controller = null;
   }
 
+  void _clearBottomProgress() {
+    if (!_showBottomProgress && _bottomProgressFraction == null) return;
+    _showBottomProgress = false;
+    _bottomProgressFraction = null;
+  }
+
   Future<void> _loadAndPlay() async {
     if (widget.videoUrl == null || widget.videoUrl!.isEmpty) {
       widget.onStopRequested();
       return;
     }
 
+    final gen = ++_loadGen;
+
     if (_controller != null && _controller!.value.isInitialized) {
-      final needSeek = _controller!.value.position >= _controller!.value.duration &&
+      if (!widget.isActive) return;
+      final needSeek = _controller!.value.position >=
+              _controller!.value.duration &&
           _controller!.value.duration.inMilliseconds > 0;
       if (needSeek) {
         await _controller!.seekTo(Duration.zero);
       }
+      if (!mounted || gen != _loadGen || !widget.isActive) return;
+      _controller!.setVolume(0);
+      _controller!.setLooping(true);
+      _controller!.removeListener(_onVideoUpdate);
       _controller!.addListener(_onVideoUpdate);
       await _controller!.play();
-      if (mounted) setState(() {});
+      if (!mounted || gen != _loadGen) return;
+      if (!widget.isActive) {
+        _stop();
+        return;
+      }
+      setState(() {});
       return;
     }
 
-    setState(() {});
+    if (_controller != null) {
+      _disposeController();
+    }
+    if (!widget.isActive) return;
+
+    if (mounted) {
+      setState(() {
+        _clearBottomProgress();
+      });
+    }
 
     try {
-      final file = await DefaultCacheManager().getSingleFile(widget.videoUrl!);
+      String? videoPath;
-      if (!mounted || !widget.isActive) return;
+      await for (final response in DefaultCacheManager().getFileStream(
-      _controller = VideoPlayerController.file(file);
+        widget.videoUrl!,
-      await _controller!.initialize();
+        withProgress: true,
-      _controller!.addListener(_onVideoUpdate);
+      )) {
-      if (mounted && widget.isActive) {
+        if (!mounted || gen != _loadGen || !widget.isActive) {
-        await _controller!.play();
+          if (mounted) {
-        setState(() {});
+            setState(_clearBottomProgress);
           }
+          return;
+        }
+        if (response is DownloadProgress) {
+          setState(() {
+            _showBottomProgress = true;
+            _bottomProgressFraction = response.progress;
+          });
+        } else if (response is FileInfo) {
+          videoPath = response.file.path;
+        }
+      }
+      if (!mounted || gen != _loadGen || !widget.isActive) {
+        if (mounted) setState(_clearBottomProgress);
+        return;
+      }
+      if (videoPath == null || videoPath.isEmpty) {
+        throw StateError('Video file stream ended without FileInfo');
+      }
+      setState(_clearBottomProgress);
+
+      _controller = VideoPlayerController.file(
+        File(videoPath),
+        videoPlayerOptions: VideoPlayerOptions(mixWithOthers: true),
+      );
+      await _controller!.initialize();
+      if (!mounted || gen != _loadGen || !widget.isActive) {
+        _disposeController();
+        return;
+      }
+      _controller!.setVolume(0);
+      _controller!.setLooping(true);
+      _controller!.addListener(_onVideoUpdate);
+      await _controller!.play();
+      if (!mounted || gen != _loadGen || !widget.isActive) {
+        _disposeController();
+        return;
+      }
+      setState(() {});
     } catch (e) {
       if (mounted) {
         _disposeController();
-        setState(() {});
+        setState(() {
+          _clearBottomProgress();
+        });
         widget.onStopRequested();
       }
     }
   }
 
   void _onVideoUpdate() {
-    if (_controller != null &&
+    // 循环播放，不需要停止
-        _controller!.value.position >= _controller!.value.duration &&
-        _controller!.value.duration.inMilliseconds > 0) {
-      _controller!.removeListener(_onVideoUpdate);
-      _controller!.seekTo(Duration.zero);
-      if (mounted) widget.onStopRequested();
   }
-  }
-
-  void _onPlayButtonTap() {
-    if (widget.isActive) {
-      widget.onStopRequested();
-      _stop();
-    } else {
-      widget.onPlayRequested();
-    }
-  }
-
-  bool get _isPlaying =>
-      widget.isActive && _controller != null && _controller!.value.isPlaying;
 
   @override
   Widget build(BuildContext context) {
@@ -160,7 +219,7 @@ class _VideoCardState extends State<VideoCard> {
                 if (showVideo)
                   Positioned.fill(
                     child: GestureDetector(
-                      onTap: _onPlayButtonTap,
+                      onTap: widget.onGenerateSimilar,
                       behavior: HitTestBehavior.opaque,
                       child: FittedBox(
                         fit: BoxFit.cover,
@@ -179,10 +238,7 @@ class _VideoCardState extends State<VideoCard> {
                 else
                   Positioned.fill(
                     child: GestureDetector(
-                      onTap: widget.videoUrl != null &&
+                      onTap: widget.onGenerateSimilar,
-                              widget.videoUrl!.isNotEmpty
-                          ? _onPlayButtonTap
-                          : null,
                       behavior: HitTestBehavior.opaque,
                       child: CachedNetworkImage(
                         imageUrl: widget.imageUrl,
@@ -232,29 +288,6 @@ class _VideoCardState extends State<VideoCard> {
                     ),
                   ),
                 ),
-                if (_isPlaying)
-                  Positioned(
-                    top: 8,
-                    left: 8,
-                    child: GestureDetector(
-                      onTap: () {
-                        widget.onStopRequested();
-                        _stop();
-                      },
-                      child: Container(
-                        padding: const EdgeInsets.all(6),
-                        decoration: BoxDecoration(
-                          color: AppColors.overlayDark,
-                          borderRadius: BorderRadius.circular(20),
-                        ),
-                        child: const Icon(
-                          LucideIcons.x,
-                          size: 16,
-                          color: AppColors.surface,
-                        ),
-                      ),
-                    ),
-                  ),
                 Positioned(
                   bottom: 16,
                   left: 12,
@@ -296,6 +329,21 @@ class _VideoCardState extends State<VideoCard> {
                     ),
                   ),
                 ),
+                if (_showBottomProgress)
+                  Positioned(
+                    left: 0,
+                    right: 0,
+                    bottom: 0,
+                    height: 2,
+                    child: LinearProgressIndicator(
+                      value: _bottomProgressFraction,
+                      minHeight: 2,
+                      backgroundColor: AppColors.surfaceAlt,
+                      valueColor: const AlwaysStoppedAnimation<Color>(
+                        AppColors.primary,
+                      ),
+                    ),
+                  ),
               ],
             ),
           ),

pubspec.yaml

@@ -35,6 +35,7 @@ dependencies:
   screen_secure: ^1.0.3
   flutter_native_splash: ^2.4.7
   android_id: ^0.5.1
+  visibility_detector: ^0.4.0+2
 
 dev_dependencies:
   flutter_test: