VideoEvent.fromMap constructor
从Map创建事件
Implementation
factory VideoEvent.fromMap(Map<String, dynamic> map) {
final String typeString = (map['type'] as String? ?? '').trim();
final VideoEventType type = _parseVideoEventType(typeString);
final Map<String, dynamic>? rawData = castMapOrNull(map['data']);
final Map<String, dynamic>? data = _augmentVideoData(typeString, rawData);
return VideoEvent(type: type, data: data, error: map['error'] as String?);
}