// create a hierarchy of nodes
MutableTreeNode root = new DefaultMutableTreeNode("Parts");
MutableTreeNode beams = new DefaultMutableTreeNode("Beams");
MutableTreeNode gears = new DefaultMutableTreeNode("Gears");
root.insert(beams, 0);
root.insert(gears, 1);
beams.insert(new DefaultMutableTreeNode("1x4 black"), 0);
beams.insert(new DefaultMutableTreeNode("1x6 black"), 1);
beams.insert(new DefaultMutableTreeNode("1x8 black"), 2);
beams.insert(new DefaultMutableTreeNode("1x12 black"), 3);
gears.insert(new DefaultMutableTreeNode("8t"), 0);
gears.insert(new DefaultMutableTreeNode("24t"), 1);
gears.insert(new DefaultMutableTreeNode("40t"), 2);
gears.insert(new DefaultMutableTreeNode("worm"), 3);
gears.insert(new DefaultMutableTreeNode("crown"), 4);
// create the JTree
final DefaultTreeModel model = new DefaultTreeModel(root);
final JTree tree = new JTree(model);
// create a text field and button to modify the data model
final JTextField nameField = new JTextField("16t");
final JButton button = new JButton("Add a part");
button.setEnabled(false);
button.addActionListener(new ActionListener( ) {
public void actionPerformed(ActionEvent e) {
TreePath tp = tree.getSelectionPath( );
MutableTreeNode insertNode =
(MutableTreeNode)tp.getLastPathComponent( );
int insertIndex = 0;
if (insertNode.getParent( ) != null) {
MutableTreeNode parent =
(MutableTreeNode)insertNode.getParent( );
insertIndex = parent.getIndex(insertNode) + 1;
insertNode = parent;
}
MutableTreeNode node =
new DefaultMutableTreeNode(nameField.getText( ));
model.insertNodeInto(node, insertNode, insertIndex);
}
});
JPanel addPanel = new JPanel(new GridLayout(2, 1));
addPanel.add(nameField);
addPanel.add(button);
// listen for selections
tree.addTreeSelectionListener(new TreeSelectionListener( ) {
public void valueChanged(TreeSelectionEvent e) {
TreePath tp = e.getNewLeadSelectionPath( );
button.setEnabled(tp != null);
}
});
// create a JFrame to hold the tree
JFrame frame = new JFrame("PartsTree v1.0");
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.setSize(200, 200);
frame.getContentPane().add(new JScrollPane(tree));
frame.getContentPane().add(addPanel, BorderLayout.SOUTH);
frame.setVisible(true);
