internal static void BreakLines(int iLine, int pos, TextSource ts)
{
Line newLine = ts.CreateLine();
for(int i=pos;i<ts[iLine].Count;i++)
newLine.Add(ts[iLine][i]);
ts[iLine].RemoveRange(pos, ts[iLine].Count - pos);
//
ts.InsertLine(iLine+1, newLine);
}