int rowCount = treeTable.getRowCount();
int currentRow;
boolean orderLineFound = false;
for (currentRow = 0; currentRow < rowCount; currentRow++) {
TreePath treePath = treeTable.getPathForRow(currentRow);
TransportableTreeNode treeNode = (TransportableTreeNode) treePath
.getLastPathComponent();
if (treeNode.getObject() instanceof OrderLine) {
orderLineFound = true;
break;
}
}