* <code>current</code> cell. Returns the topmost cell if there are no
* more cells behind <code>current</code>. Note: This does only return
* visible cells.
*/
public Object getNextCellForLocation(Object current, double x, double y) {
CellView cur = graphLayoutCache.getMapping(current, false);
CellView cell = getNextViewAt(cur, x, y);
if (cell != null)
return cell.getCell();
return null;
}