init method
Initializes the provider by loading all necessary fonts.
requiredFamilies are the font families actually used in the document;
the provider tries to load them from the OS so the PDF embeds the real fonts.
Implementation
Future<void> init([Set<String> requiredFamilies = const {}]) async {
if (_initialized) return;
// Load bundled fonts (fallback)
await _loadBundledFonts();
// Load any system fonts that match families used in the document
for (final family in requiredFamilies) {
if (family.trim().isEmpty) continue;
await _tryLoadSystemFont(family);
}
_initialized = true;
}