getOffsetBefore method

int getOffsetBefore (int offset)

Returns the closest offset before offset at which the inout cursor can be positioned.

Implementation 

int getOffsetBefore(int offset) {
  final int prevCodeUnit = _text.codeUnitAt(offset - 1);
  if (prevCodeUnit == null)
    return null;
  // TODO(goderbauer): doesn't handle extended grapheme clusters with more than one Unicode scalar value (https://github.com/flutter/flutter/issues/13404).
  return _isUtf16Surrogate(prevCodeUnit) ? offset - 2 : offset - 1;
}