fix(home): 修复频道快速切换卡 loading

lib/pages/player/player_logic.dart

@@ -102,6 +102,13 @@ class PlayerLogic extends ChangeNotifier {
   bool _disposed = false;
   PlayerFactory? _sessionFactory;
   PlaybackCoordinator? _sessionCoordinator;
+  int feedRevision = 0;
+  List<Drama> _latestFeed = const [];
+  String? _latestKeepDramaId;
+  bool _latestResetToFirst = false;
+  bool _feedUpdateRunning = false;
+  bool _hasPendingFeed = false;
+  Future<void> _feedUpdateFuture = Future<void>.value();
 
   /// [start] 是否已经跑过：没跑过时 session/pages 还是 late 未初始化，
   /// dispose 不能直接碰它们（例如页面构建失败或纯逻辑测试）。
@@ -111,6 +118,9 @@ class PlayerLogic extends ChangeNotifier {
 
   bool get chromeHidden => immersive;
 
+  /// 最近一次 feed 更新流程完成；测试和页面退出可等待它结束。
+  Future<void> get feedUpdateSettled => _feedUpdateFuture;
+
   /// 当前 PageView 对应用户正在观看的短剧 id，尚未起播时为 null。
   String? get currentDramaId {
     if (!_started || visibleIndices.isEmpty) return null;
@@ -173,38 +183,26 @@ class PlayerLogic extends ChangeNotifier {
     unawaited(selectEpisode(initialIndex));
   }
 
-  /// 原地替换首页 feed 队列；频道变化时重置到第 1 个，刷新时尽量保留当前剧。
-  void updateFeed(List<Drama> dramas, {String? keepDramaId}) {
-    final currentId = currentDramaId;
-    final nextQueue = PlaybackQueue.home(List<Drama>.unmodifiable(dramas));
-    final nextVisible = List<int>.generate(nextQueue.length, (index) => index);
-    final nextEpisodes = [for (final entry in nextQueue.entries) entry.episode];
-    feedDramas = List<Drama>.unmodifiable(dramas);
-    queue = nextQueue;
-    visibleIndices = nextVisible;
-    if (dramas.isNotEmpty) pageDrama = dramas.first;
-    if (!_started) return;
-    if (nextQueue.length == 0) {
-      session.setRouteVisible(false);
-      notify();
+  /// 串行替换首页 feed 队列；频道变化时重置到第 1 个，刷新时尽量保留当前剧。
+  void updateFeed(
+    List<Drama> dramas, {
+    String? keepDramaId,
+    bool resetToFirst = false,
+  }) {
+    feedRevision++;
+    pageRequest++;
+    _latestFeed = List<Drama>.unmodifiable(dramas);
+    _latestKeepDramaId = keepDramaId;
+    _latestResetToFirst = resetToFirst;
+    _hasPendingFeed = true;
+    if (!_started) {
+      feedDramas = _latestFeed;
       return;
     }
-    final keepIndex = keepDramaId != null && keepDramaId == currentId
-        ? nextQueue.entries.indexWhere((entry) => entry.drama.id == keepDramaId)
-        : -1;
-    if (keepIndex >= 0 && session.active != null) {
-      sessionEpisodes
-        ..clear()
-        ..addAll(nextEpisodes);
-      session.remapCurrentIndex(
-        keepIndex,
-        preloadIndex: nextVisibleIndex(keepIndex),
-      );
-      _jumpToFeedPage(keepIndex);
-      notify();
-      return;
+    if (!_feedUpdateRunning) {
+      _feedUpdateFuture = _drainFeedUpdates();
+      unawaited(_feedUpdateFuture);
     }
-    _replaceSession(nextEpisodes, keepIndex >= 0 ? keepIndex : 0);
   }
 
   PlaybackSession _createSession(
@@ -222,7 +220,77 @@ class PlayerLogic extends ChangeNotifier {
     );
   }
 
-  void _replaceSession(List<Episode> nextEpisodes, int targetIndex) {
+  Future<void> _drainFeedUpdates() async {
+    _feedUpdateRunning = true;
+    while (true) {
+      if (!_hasPendingFeed) {
+        _feedUpdateRunning = false;
+        return;
+      }
+      _hasPendingFeed = false;
+      final revision = feedRevision;
+      final dramas = _latestFeed;
+      final keepDramaId = _latestKeepDramaId;
+      final resetToFirst = _latestResetToFirst;
+      if (revision != feedRevision) continue;
+      await _applyFeedUpdate(
+        dramas,
+        keepDramaId: keepDramaId,
+        resetToFirst: resetToFirst,
+        revision: revision,
+      );
+    }
+  }
+
+  Future<void> _applyFeedUpdate(
+    List<Drama> dramas, {
+    required String? keepDramaId,
+    required bool resetToFirst,
+    required int revision,
+  }) async {
+    if (!_started || revision != feedRevision) return;
+    final currentId = currentDramaId;
+    final nextQueue = PlaybackQueue.home(dramas);
+    final nextVisible = List<int>.generate(nextQueue.length, (index) => index);
+    final nextEpisodes = [for (final entry in nextQueue.entries) entry.episode];
+    feedDramas = dramas;
+    queue = nextQueue;
+    visibleIndices = nextVisible;
+    if (dramas.isNotEmpty) pageDrama = dramas.first;
+    if (nextQueue.length == 0) {
+      session.setRouteVisible(false);
+      notify();
+      return;
+    }
+    final keepIndex =
+        !resetToFirst && keepDramaId != null && keepDramaId == currentId
+        ? nextQueue.entries.indexWhere((entry) => entry.drama.id == keepDramaId)
+        : -1;
+    if (keepIndex >= 0 && session.active != null) {
+      sessionEpisodes
+        ..clear()
+        ..addAll(nextEpisodes);
+      session.remapCurrentIndex(
+        keepIndex,
+        preloadIndex: nextVisibleIndex(keepIndex),
+      );
+      _jumpToFeedPage(keepIndex);
+      notify();
+      return;
+    }
+    await _replaceSession(
+      nextEpisodes,
+      keepIndex >= 0 ? keepIndex : 0,
+      revision: revision,
+    );
+  }
+
+  Future<void> _replaceSession(
+    List<Episode> nextEpisodes,
+    int targetIndex, {
+    required int revision,
+  }) async {
+    if (revision != feedRevision) return;
     final factory = _sessionFactory;
     final coordinator = _sessionCoordinator;
     if (factory == null || coordinator == null) return;
@@ -232,12 +300,14 @@ class PlayerLogic extends ChangeNotifier {
     trackedPlayer = null;
     trackedEpisode = null;
     trackedDrama = null;
-    session = _createSession(factory, coordinator);
-    session.setRouteVisible(active && visibleIndices.isNotEmpty);
-    unawaited(previous.close());
-    _jumpToFeedPage(targetIndex);
-    unawaited(selectEpisode(targetIndex));
+    final nextSession = _createSession(factory, coordinator);
+    session = nextSession;
+    nextSession.setRouteVisible(active && visibleIndices.isNotEmpty);
     notify();
+    await previous.close();
+    if (revision != feedRevision || !identical(session, nextSession)) return;
+    _jumpToFeedPage(targetIndex);
+    await selectEpisode(targetIndex, revision: revision);
   }
 
   void _jumpToFeedPage(int index) {
@@ -625,15 +695,24 @@ class PlayerLogic extends ChangeNotifier {
     );
   }
 
-  Future<void> selectEpisode(int index) async {
+  Future<void> selectEpisode(int index, {int? revision}) async {
+    final feedRevisionAtStart = revision ?? feedRevision;
     final request = ++pageRequest;
     cancelScrub();
     // Capture the old position synchronously, persist without blocking a swipe.
     unawaited(saveCurrentProgress());
-    if (request != pageRequest || !isMounted()) return;
+    if (request != pageRequest ||
+        feedRevisionAtStart != feedRevision ||
+        !isMounted()) {
+      return;
+    }
     // 起播前先要票据：拿不到就不起播，交给三态 UI 提示（失败可重试）
     final ready = await ensureTicket(index);
-    if (request != pageRequest || !isMounted()) return;
+    if (request != pageRequest ||
+        feedRevisionAtStart != feedRevision ||
+        !isMounted()) {
+      return;
+    }
     if (!ready && ticketError != null) return;
     await session.select(index, preloadIndex: nextVisibleIndex(index));
   }

lib/pages/player/player_view.dart

@@ -2,7 +2,6 @@
 
 import 'dart:async';
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:provider/provider.dart';
@@ -131,20 +130,25 @@ class _PlayerPageState extends State<PlayerPage>
   void didUpdateWidget(covariant PlayerPage oldWidget) {
     super.didUpdateWidget(oldWidget);
     logic.attach(widget, isMounted: () => mounted);
+    final channelChanged = oldWidget.feedChannel != widget.feedChannel;
+    final feedChanged =
+        _feedSignature(oldWidget.feedDramas) !=
+        _feedSignature(widget.feedDramas);
     if (widget.homeMode &&
         widget.feedDramas != null &&
-        (!listEquals(oldWidget.feedDramas, widget.feedDramas) ||
-            oldWidget.feedChannel != widget.feedChannel)) {
+        (feedChanged || channelChanged)) {
       logic.updateFeed(
         widget.feedDramas!,
-        keepDramaId: oldWidget.feedChannel == widget.feedChannel
-            ? logic.currentDramaId
-            : null,
+        keepDramaId: channelChanged ? null : logic.currentDramaId,
+        resetToFirst: channelChanged,
       );
     }
     logic.onPageUpdated(oldWidget);
   }
 
+  String _feedSignature(List<Drama>? dramas) =>
+      dramas == null ? '' : dramas.map((drama) => drama.id).join('|');
+
   @override
   void didChangeDependencies() {
     super.didChangeDependencies();