Event på JTree

Her er et eksempel der sætter et JTree op
og udskriver når der trykkes på de enkelte
elementer i træet.

import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import java.util.Vector;
public class TreeDemo {
    public static void main( String[] args ) {
    Vector root = new Vector();
    root.add( \"First\" );
    root.add( \"Second\" );
    Vector subtree = new Vector();
    subtree.add( \"2.1\" );
    subtree.add( \"2.2\" );
    Vector subsubtree = new Vector();
    subsubtree.add( \"2.3.1\" );
    subsubtree.add( \"2.3.2\" );
    subtree.add( subsubtree );
    root.add( subtree );
    root.add( \"Third\" );
    JTree tree = new JTree( root );
    tree.addTreeSelectionListener( new MyTreeSelectionListener() );
    TreeModel model = new MyTreeModel( root );
    JScrollPane pane = new JScrollPane( tree );
    JFrame frame = new JFrame( \"Tree\" );
    Container c = frame.getContentPane();
    c.add( pane );
    frame.pack();
    frame.show();
    } // main
    public static class MyTreeModel implements TreeModel {
    private Vector root;
    public MyTreeModel( Vector root ) {
        this.root = root;
    } // constructor
    public Object getRoot() {
        return root;
    } // getRoot
    public boolean isLeaf( Object node ) {
        return ! (node instanceof Vector);
    } // isLeaf
    public int getChildCount( Object parent ) {
        return ((Vector)parent).size();
    } // getChildCount
    public Object getChild( Object parent, int i ) {
        return ((Vector)parent).get( i );
    } // getChild
    public int getIndexOfChild( Object parent, Object child ) {
        return ((Vector)parent).indexOf( child );
    } // getIndexOfChild
    public void valueForPathChanged( TreePath path, Object newValue ) {
        System.out.println(\"path=\"+path);
    } // valueForPathChanged
    public void addTreeModelListener( TreeModelListener listener ) {
    } // addTreeModelListener
    public void removeTreeModelListener( TreeModelListener listener ) {
    } // removeTreeModelListener
    } // MyTreeModel
    public static class MyTreeSelectionListener implements TreeSelectionListener {
    public void valueChanged( TreeSelectionEvent tse ) {
        TreePath path = tse.getPath();
        Object o = path.getLastPathComponent();
        System.out.println(\"o=\"+o);
    } // valueChanged
    } // TreeSelectionModel
} // TreeDemo