fix(player): 使用雪碧图预热首帧兜底

lib/core/data/services/sprite_thumbnail_axis.dart

@@ -132,36 +132,37 @@ class SpriteThumbnailAxisService extends ChangeNotifier
   SpriteThumbnailAxisService({
     SpriteThumbnailAssetLoader? loader,
     this.cacheTtl = spriteVttCacheTtl,
+    this.spriteCacheCapacity = spriteImageCacheCapacity,
     DateTime Function()? now,
   }) : _loader = loader ?? DioSpriteThumbnailAssetLoader(),
        _now = now ?? DateTime.now;
 
   final SpriteThumbnailAssetLoader _loader;
   final Duration cacheTtl;
+  final int spriteCacheCapacity;
   final DateTime Function() _now;
   final Map<String, _CachedAxis> _axisCache = {};
   final Map<String, Future<SpriteThumbnailAxis>> _axisRequests = {};
   final LinkedHashMap<String, _CachedSprite> _spriteCache = LinkedHashMap();
   final Map<String, Future<_CachedSprite?>> _spriteRequests = {};
   final Set<String> _failedSprites = {};
-  String? _activeAxisUrl;
-  int _axisGeneration = 0;
   bool _disposed = false;
 
   @visibleForTesting
   int get spriteCacheSize => _spriteCache.length;
 
   @visibleForTesting
-  List<String> get spriteCacheKeys => _spriteCache.keys.toList();
+  List<String> get spriteCacheKeys => _spriteCache.keys
+      .map((url) => Uri.tryParse(url)?.pathSegments.lastOrNull ?? url)
+      .toList();
 
   /// 播放器就绪时预取当前 cue 与相邻 sprite，拖动帧不触发网络或解码。
   @override
   Future<void> prepareAt(String? thumbnailsUrl, Duration position) async {
     final url = _normalizeUrl(thumbnailsUrl);
     if (_disposed || url == null) return;
-    _activateAxis(url);
     final axis = await _loadAxis(url);
-    if (_disposed || _activeAxisUrl != url) return;
+    if (_disposed) return;
     for (final cue in _prefetchCues(axis, position)) {
       await _ensureSprite(axis, cue);
     }
@@ -170,7 +171,7 @@ class SpriteThumbnailAxisService extends ChangeNotifier
   @override
   bool hasAxis(String? thumbnailsUrl) {
     final url = _normalizeUrl(thumbnailsUrl);
-    if (url == null || url != _activeAxisUrl) return false;
+    if (url == null) return false;
     return _readAxis(url) != null;
   }
 
@@ -180,12 +181,14 @@ class SpriteThumbnailAxisService extends ChangeNotifier
     Duration position,
   ) {
     final url = _normalizeUrl(thumbnailsUrl);
-    if (url == null || url != _activeAxisUrl) return null;
+    if (url == null) return null;
     final axis = _readAxis(url);
     if (axis == null) return null;
     final cue = selectSpriteThumbnailCue(axis.cues, position);
     if (cue == null) return null;
-    final cached = _readSprite(cue.spriteFile);
+    final cached = _readSprite(
+      axis.resolveSpriteUri(cue.spriteFile).toString(),
+    );
     if (cached == null) return null;
     final sourceRect = _scaledSourceRect(cached, cue.sourceRect);
     if (sourceRect == null) return null;
@@ -206,13 +209,6 @@ class SpriteThumbnailAxisService extends ChangeNotifier
     super.dispose();
   }
 
-  void _activateAxis(String url) {
-    if (_activeAxisUrl == url) return;
-    _activeAxisUrl = url;
-    _axisGeneration++;
-    _clearSprites();
-  }
-
   Future<SpriteThumbnailAxis> _loadAxis(String url) {
     final cached = _readAxis(url);
     if (cached != null) return Future.value(cached);
@@ -239,7 +235,6 @@ class SpriteThumbnailAxisService extends ChangeNotifier
       } on SpriteThumbnailForbiddenException {
         if (_disposed) return SpriteThumbnailAxis.empty(url);
         _axisCache.remove(url);
-        if (_activeAxisUrl == url) _clearSprites();
       } catch (_) {
         break;
       }
@@ -293,23 +288,23 @@ class SpriteThumbnailAxisService extends ChangeNotifier
     SpriteThumbnailAxis axis,
     SpriteThumbnailCue cue,
   ) {
-    final cached = _readSprite(cue.spriteFile);
+    final spriteUrl = axis.resolveSpriteUri(cue.spriteFile).toString();
+    final cached = _readSprite(spriteUrl);
     if (cached != null) return Future.value(cached);
-    if (_failedSprites.contains(cue.spriteFile)) return Future.value();
-    final existing = _spriteRequests[cue.spriteFile];
+    if (_failedSprites.contains(spriteUrl)) return Future.value();
+    final existing = _spriteRequests[spriteUrl];
     if (existing != null) return existing;
-    final generation = _axisGeneration;
-    final request = _loadSprite(axis, cue, generation);
-    _spriteRequests[cue.spriteFile] = request;
+    final request = _loadSprite(axis, cue, spriteUrl);
+    _spriteRequests[spriteUrl] = request;
     return request.whenComplete(() {
-      _spriteRequests.remove(cue.spriteFile);
+      _spriteRequests.remove(spriteUrl);
     });
   }
 
   Future<_CachedSprite?> _loadSprite(
     SpriteThumbnailAxis axis,
     SpriteThumbnailCue cue,
-    int generation,
+    String spriteUrl,
   ) async {
     SpriteThumbnailDecodedImage? decoded;
     try {
@@ -318,16 +313,16 @@ class SpriteThumbnailAxisService extends ChangeNotifier
       decoded = null;
     }
     if (decoded == null) {
-      _failedSprites.add(cue.spriteFile);
+      _failedSprites.add(spriteUrl);
       if (!_disposed) notifyListeners();
       return null;
     }
-    if (_disposed || generation != _axisGeneration) {
+    if (_disposed) {
       decoded.image.dispose();
       return null;
     }
     final cached = _CachedSprite(decoded);
-    _putSprite(cue.spriteFile, cached);
+    _putSprite(spriteUrl, cached);
     notifyListeners();
     return cached;
   }
@@ -342,7 +337,7 @@ class SpriteThumbnailAxisService extends ChangeNotifier
   void _putSprite(String key, _CachedSprite value) {
     _spriteCache.remove(key)?.decoded.image.dispose();
     _spriteCache[key] = value;
-    while (_spriteCache.length > spriteImageCacheCapacity) {
+    while (_spriteCache.length > spriteCacheCapacity) {
       final oldest = _spriteCache.remove(_spriteCache.keys.first);
       oldest?.decoded.image.dispose();
     }
@@ -378,8 +373,6 @@ class SpriteThumbnailAxisService extends ChangeNotifier
   }
 
   void _clearAll() {
-    _axisGeneration++;
-    _activeAxisUrl = null;
     _axisCache.clear();
     _axisRequests.clear();
     _clearSprites();