int col = getColumn(de.getClientX());
int row = getRowPosition(col, de.getClientY());
if (col != insertCol || row != insertRow) {
PortalEvent pe = new PortalEvent(this, active, startCol, startRow, col, row);
if (fireEvent(Events.ValidateDrop, pe)) {
addInsert(col, row);
} else {
insertCol = startCol;
insertRow = startRow;