applyRule method

  1. @override
Delta? applyRule(
  1. Document document,
  2. int index, {
  3. int? len,
  4. Object? data,
  5. Attribute? attribute,
})
override

Applies heuristic rule to an operation on a document and returns resulting Delta.

Implementation

@override
Delta? applyRule(
  Document document,
  int index, {
  int? len,
  Object? data,
  Attribute? attribute,
}) {
  if (attribute == null || attribute.key != Attribute.style.key) {
    return null;
  }

  assert(len == 1 && data == null);

  final delta = Delta()
    ..retain(index)
    ..retain(1, attribute.toJson());

  return delta;
}