convert method

List<TextSpan> convert([ Color? linkColor ])

转换的思路：将 开始标签 的属性转为 合适的style, 并将其存入集合中 a开始标签支持的属性：href 文本标签 去获取style集合的最后一个元素 并应用style样式 结束标签 则将集合的最后一个元素删除

Implementation

List<TextSpan> convert([Color? linkColor]) {
  // 优先使用外部提供的样式
  final TextStyle style = _defaultStyle ??
      TextStyle(
        fontSize: 14,
        decoration: TextDecoration.none,
        fontWeight: FontWeight.normal,
        color: BaseThemeConfig.instance
            .getConfig()
            .commonConfig
            .colorTextImportant,
      );

  final List<TextSpan> spans = [];
  _eventList.forEach((xmlEvent) {
    if (xmlEvent is xml.XmlStartElementEvent) {
      if (!xmlEvent.isSelfClosing) {
        final _Tag tag = _Tag();
        TextStyle textStyle = style.copyWith();
        if (xmlEvent.name == 'font') {
          xmlEvent.attributes.forEach((attr) {
            switch (attr.name) {
              case 'color':
                textStyle = textStyle.apply(
                  color: ConvertUtil.generateColorByString(attr.value),
                );
                break;
              case 'weight':
                FontWeight fontWeight =
                    ConvertUtil.generateFontWidgetByString(attr.value);
                textStyle = textStyle.apply(
                  fontWeightDelta: fontWeight.index - FontWeight.normal.index,
                );
                break;
              case 'size':
                textStyle = textStyle.apply(
                  fontSizeDelta:
                      ConvertUtil.generateFontSize(attr.value) - 13,
                );
                break;
            }
          });
          tag.isLink = false;
        }

        if (xmlEvent.name == 'strong') {
          tag.isLink = false;
          textStyle = textStyle.apply(fontWeightDelta: 2);
        }

        if (xmlEvent.name == 'a') {
          tag.isLink = true;
          xmlEvent.attributes.forEach((attr) {
            switch (attr.name) {
              case 'href':
                textStyle = textStyle.apply(
                  color: linkColor ??
                      BaseThemeConfig.instance
                          .getConfig()
                          .commonConfig
                          .brandPrimary,
                );
                tag.linkUrl = attr.value;
                break;
            }
          });
        }
        tag.name = xmlEvent.name;
        tag.style = textStyle;
        stack.add(tag);
      } else {
        if (xmlEvent.name == 'br') {
          spans.add(TextSpan(text: '\n'));
        }
      }
    }

    if (xmlEvent is xml.XmlTextEvent) {
      _Tag tag = _Tag();
      tag.style = style.copyWith();
      if (stack.isNotEmpty) {
        tag = stack.last;
      }
      TextSpan textSpan = _createTextSpan(xmlEvent.value, tag);
      spans.add(textSpan);
    }

    if (xmlEvent is xml.XmlEndElementEvent) {
      _Tag top = stack.removeLast();
      if (top.name != xmlEvent.name) {
        debugPrint('Error format HTML');
        return;
      }
    }
  });

  return spans;
}