internal EditableTextLine GetTextLineAtPos(int y)
 {
     if (lineCollection != null)
     {
         if (lineCollection is List <EditableTextLine> )
         {
             List <EditableTextLine> lines = lineCollection as List <EditableTextLine>;
             if (lines != null)
             {
                 int j = lines.Count;
                 for (int i = 0; i < j; ++i)
                 {
                     EditableTextLine line = lines[i];
                     if (line.IntersectsWith(y))
                     {
                         return(line);
                     }
                 }
             }
         }
         else
         {
             EditableTextLine line = (EditableTextLine)lineCollection;
             if (line.IntersectsWith(y))
             {
                 return(line);
             }
         }
     }
     return(null);
 }