private void MoveSelectedLines(string section)
{
_rtb.SuspendPainting();
var padded = GetPaddedText(Text);
var i = _rtb.SelectionStart + 1;
var j = i + Math.Max(0, _rtb.SelectionLength - 1);
var cutIndex = Helper.GetLineStart(padded, i);
var k = Helper.GetLineEnd(padded, j);
var copyLength = k - cutIndex;
var cutLength = copyLength + (k < padded.Length ? 1 : 0);
var copiedText = padded.Substring(cutIndex, copyLength);
_rtb.Select(cutIndex - 1, cutLength);
_rtb.SelectedText = "";
padded = GetPaddedText(Text);
var insertIndex = GetAppendIndex(padded, section);
if (insertIndex == -1)
{
_rtb.SelectedText = copiedText + "\n";
}
else
{
_rtb.Select(insertIndex - 1, 0);
var lengthBefore = _rtb.TextLength;
_rtb.SelectedText = "\n" + copiedText;
_rtb.Select(cutIndex - 1 + (insertIndex < cutIndex ? _rtb.TextLength - lengthBefore : 0), 0);
}
_rtb.ResumePainting();
}