onMarkup method

Implementation

@override
HypertextSpan onMarkup(List<HypertextSpan>? children, MarkupContext ctx) {
  final url = ctx.get('src');

  HypertextSpan? span;
  if (url.isNotEmpty) {
    double? width = ctx.getDouble('width');
    double? height = ctx.getDouble('height');
    if (width == null && height == null) {
      final s = ctx.getDoubles('size');
      if (s?.length == 1) {
        width = height = s![0];
      } else if (s?.length == 2) {
        width = s![0];
        height = s[1];
      }
    }
    final fit = ctx.switchT(ctx.get('fit'), mpBoxFit);
    final alignment = ctx.switchT(ctx.get('align'), mpAlignment);
    final plAlignment = ctx.switchT(ctx.get('alignment'), mpPLAlignment);
    final baseline = ctx.switchT(ctx.get('baseline'), mpBaselines);

    final effectiveAlignment =
        plAlignment ?? this.alignment ?? PlaceholderAlignment.middle;
    final effectiveBaseline = baseline ?? this.baseline;

    final builder = imageBuilder ?? imageMarkupBuilder;

    span = HypertextWidgetSpan(
      alignment: effectiveAlignment,
      baseline: effectiveBaseline,
      child: Builder(
        builder: (c) {
          return builder(
                c,
                url!,
                width: width,
                height: height,
                fit: fit,
                alignment: alignment,
              ) ??
              const SizedBox.shrink();
        },
      ),
    );
  }

  // 包装图片及其子元素到一个元素中
  if (children.isNotEmpty) {
    span = HypertextTextSpan(
      children: [if (span != null) span, ...?children],
    );
  }

  return span ?? kEmptyHypertextSpan;
}