renderThumbnail method

Future<HTMLImageElement?> renderThumbnail({ String? renderedHTML, bool includeDocumentStyles = true, String? styles, int? width = 800, int? height = 600, })

Implementation

Future<HTMLImageElement?> renderThumbnail({
  String? renderedHTML,
  bool includeDocumentStyles = true,
  String? styles,
  int? width = 800,
  int? height = 600,
}) async {
  renderedHTML ??= renderDomGenerator.generatedHTMLTrees.join('\n');
  if (isEmptyObject(renderedHTML)) return null;

  var svgStyles = '';
  if (includeDocumentStyles) {
    // `rules` is a JS `CSSRuleList` (not a Dart `List`, so a
    // `whereType<List<CSSRule>>()` dropped every style sheet):
    var rules = getAllCssStyleSheet()
        .expand((e) => e.rules.toList())
        .toList();

    svgStyles = rules.map((e) => e.cssText).join('\n');
  }

  if (isNotEmptyObject(styles)) {
    // Appended to the document styles (it used to replace them):
    svgStyles += '\n$styles';
  }

  var svg = htmlAsSvgContent(
    renderedHTML,
    width: width,
    height: height,
    style: svgStyles,
  );

  var thumbnail = UISVG(
    parent,
    svgContent: svg,
    width: '${width}px',
    height: '${height}px',
  );

  var renderedImage = await thumbnail.buildRenderedImage();

  return renderedImage;
}