JButton circularButton = new JButton("Circular Layout");
circularButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
fd = new CircularLayout(gp);
if (fd instanceof RootNodeLayout) {
RootNodeLayout temp = (RootNodeLayout) fd;
temp.setRootNodes(currentSelection);
}
gp.getNanoGraph().setLayout(fd);