resolveFontFaceRules static method

void resolveFontFaceRules(CSSFontFaceRule fontFaceRule, double contextId, String? baseHref)

Implementation

static void resolveFontFaceRules(CSSFontFaceRule fontFaceRule, double contextId, String? baseHref) async {
  CSSStyleDeclaration declaration = fontFaceRule.declarations;
  String fontFamily = declaration.getPropertyValue('fontFamily');
  String url = declaration.getPropertyValue('src');
  if (fontFamily.isNotEmpty && url.isNotEmpty && CSSFunction.isFunction(url)) {
    String? tmp_src;
    List<CSSFunctionalNotation> functions = CSSFunction.parseFunction(url);

    List<_Font> fonts = [];

    for(int i = 0; i < functions.length; i ++) {
      CSSFunctionalNotation notation = functions[i];
      if (notation.name == 'url') {
        tmp_src = notation.args[0];

        tmp_src = removeQuotationMark(tmp_src);

        if (tmp_src.startsWith('data')) {
          String tmp_content = tmp_src.split(';').last;
          if (tmp_content.startsWith('base64')) {
            String base64 = tmp_src.split(',').last;
            try {
              Uint8List decoded = base64Decode(base64);
              if (decoded.isNotEmpty) {
                fonts.add(_Font.content(decoded));
              }
            } catch(e) {}
          }

        } else {
          String formatFromExt = tmp_src.split('.').last;
          fonts.add(_Font(tmp_src, formatFromExt));
        }

      }
    }

    _Font? targetFont = fonts.firstWhereOrNull((f) {
      return supportedFonts.contains(f.format);
    });

    if (targetFont == null) return;

    try {
      if (targetFont.content.isNotEmpty) {
        Uint8List content = targetFont.content;
        Future<ByteData> bytes = Future.value(ByteData.sublistView(content));
        FontLoader loader = FontLoader(fontFamily);
        SchedulerBinding.instance.addPostFrameCallback((timeStamp) {
          loader.addFont(bytes);
          loader.load();
        });
      } else {
        Uri? uri = _resolveFontSource(contextId, targetFont.src, baseHref);
        if (uri == null) return;
        final WebFController controller = WebFController.getControllerOfJSContextId(contextId)!;
        WebFBundle bundle = controller.getPreloadBundleFromUrl(uri.toString()) ?? WebFBundle.fromUrl(uri.toString());
        await bundle.resolve(baseUrl: controller.url, uriParser: controller.uriParser);
        await bundle.obtainData(controller.view.contextId);
        assert(bundle.isResolved, 'Failed to obtain $url');
        FontLoader loader = FontLoader(removeQuotationMark(fontFamily));
        Future<ByteData> bytes = Future.value(bundle.data?.buffer.asByteData());
        SchedulerBinding.instance.addPostFrameCallback((timeStamp) {
          loader.addFont(bytes);
          loader.load();
        });
      }


    } catch(e, stack) {
      print('$e\n$stack');
      return;
    }
  }
}