convert method

@override Document convert(Delta input)

Converts input and returns the result of the conversion.

Implementation

@override
Document convert(Delta input) {
  final iterator = input.iterator;
  final document = Document.blank(withInitialText: false);

  Node node = paragraphNode();
  int index = 0;

  while (iterator.moveNext()) {
    final op = iterator.current;
    final attributes = op.attributes;
    if (op is TextInsert) {
      if (op.text == _newLineSymbol) {
        if (attributes != null) {
          node = _applyListStyleIfNeeded(node, attributes);
          node = _applyHeadingStyleIfNeeded(node, attributes);
          node = _applyBlockquoteIfNeeded(node, attributes);
          _applyIndentIfNeeded(node, attributes);
        }
        if (_isIndentBulletedList(attributes)) {
          final level = _indentLevel(attributes);
          final path = [
            ...nestedLists[level - 1]!.last.path,
            nestedLists[level]!.length - 1,
          ];
          document.insert(path, [node]);
        } else {
          document.insert([index++], [node]);
        }
        node = paragraphNode();
      } else {
        final texts = op.text.split('\n');
        if (texts.length > 1) {
          node.delta?.insert(texts[0]);
          document.insert([index++], [node]);
          node = paragraphNode(delta: Delta()..insert(texts[1]));
        } else {
          _applyStyle(node, op.text, attributes);
        }
      }
    } else {
      throw UnsupportedError('only support text insert operation');
    }
  }

  if (index == 0) {
    document.insert([index], [node]);
  }

  return document;
}