getCacheDir method
Ensures the cache directory exists and returns it.
Implementation
Future<Directory> getCacheDir() async {
if (_initialized && _cacheDir != null) return _cacheDir!;
final appDir = await getApplicationDocumentsDirectory();
final dir = Directory('${appDir.path}/qfc4_fonts');
if (!dir.existsSync()) {
await dir.create(recursive: true);
}
_cacheDir = dir;
_initialized = true;
return dir;
}