apply method

SpanBuilder apply(
  1. InlineSpan span,
  2. {String whereText,
  3. int from,
  4. int to,
  5. dynamic onTap(
      ),
    1. RecognizerBuilder recognizerBuilder}
    )

    Implementation

    SpanBuilder apply(InlineSpan span,
    {String whereText,
    int from,
    int to,
    Function() onTap,
    RecognizerBuilder recognizerBuilder}) {
  /// turn any [onTap] into [RecognizerBuilder]
  if (onTap != null && recognizerBuilder == null) {
    recognizerBuilder = () => TapGestureRecognizer()..onTap = onTap;
  }

  /// convert [TextSpan] into [_ManagedTextSpan] with a [RecoginzerBuilder]
  if (span is TextSpan) {
    /// ignore: avoid_as
    span = (span as TextSpan).managed(recognizerBuilder);
  }

  /// if [whereText] is not provided then we try to figure it out:
  /// 1. from [from, to] range (if both params are passed)
  /// 2. from passed [TextSpan]
  /// 3. from lousy [from, to] range
  if (whereText == null) {
    if (from != null && to != null) {
      whereText = sourceText.substring(from, to);
    } else if (span is TextSpan) {
      whereText = span.text;
    } else {
      if (from == null && to == null) {
        return this;
      }
      whereText = sourceText.substring(from ?? 0, to ?? sourceText.length);
    }
  }

  /// if we pass whereText + from, we will try to do the search starting from that point
  /// therefor we need offset
  final offset = from ?? 0;

  final _sourceText =
      sourceText.substring(from ?? 0, to ?? sourceText.length);

  if (whereText != null) {
    from = _sourceText.indexOf(whereText);
    if (from == -1) {
      return this;
    }
    to = from + whereText.length;
  }

  /// finally we appen calculated SpanPosition
  return add(SpanEntity(start: offset + from, end: offset + to, span: span));
}