shiftElements method

void shiftElements(int start, int count, int offset)

Implementation

void shiftElements(int start, int count, int offset) {
  if (count < 0) return;
  if (start < 0 || start >= _length)
    throw Exception('Start argument is out of range');
  if (start + offset < 0)
    throw Exception('Can not shift elements in list beyond index 0');
  if (offset > 0) {
    for (var i = count - 1; i >= 0; i--) {
      this[start + i + offset] = this[start + i];
    }
    var expandListBy = (start + count + offset) - _length;
    if (expandListBy > 0) {
      _length += expandListBy;
      while (_length > _array.length) {
        length--;
        _startIndex++;
      }
    }
  } else {
    for (var i = 0; i < count; i++) {
      this[start + i + offset] = this[start + i];
    }
  }
}