public Rectangle CellRect(Cell cell)
{
if (cell == null || cell.Row == null || cell.InternalIndex == -1)
return Rectangle.Empty;
if (this.TableModel == null || this.ColumnModel == null)
return Rectangle.Empty;
int row = this.TableModel.Rows.IndexOf(cell.Row);
int col = cell.InternalIndex;
return this.CellRect(row, col);
}