private VisualTextLine CutStandardLine(VisualTextLine line, int startIndex, int count) { var contents = line.GetStringContents()[0]; var newText = string.Empty; if (startIndex + count == line.Length) { newText = contents.Substring(startIndex); } else { newText = contents.Substring(startIndex, count - startIndex); } return VisualTextLine.Create(newText, line.Index); }