needsBidiPlaceholderFix function

bool needsBidiPlaceholderFix(InlineSpan span)

Whether span can be hit by the placeholder-ordering bug.

Two or more inline widgets are needed for an ordering to exist at all, and some right-to-left text is needed for the visual order to differ from the logical one. Anything else keeps using a stock Text.

Implementation

bool needsBidiPlaceholderFix(InlineSpan span) {
  var placeholders = 0;
  var hasRtl = false;

  void visit(InlineSpan current) {
    if (current is PlaceholderSpan) {
      placeholders++;
    }
    if (current is TextSpan) {
      final text = current.text;
      if (!hasRtl && text != null && _rtlPattern.hasMatch(text)) {
        hasRtl = true;
      }
      final children = current.children;
      if (children != null) {
        for (final child in children) {
          visit(child);
        }
      }
    }
  }

  visit(span);
  return placeholders >= 2 && hasRtl;
}