testjtree2.java

java2 primer plus一书源程序

/*
 * TestJTree2.java
 *
 * Created on September 5, 2002, 11:12 AM
 */

package ch17;

import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

/**
 *
 * @author  Stephen Potts
 */
public class TestJTree2 extends JFrame implements TreeSelectionListener
{
    private JTree tree1;
    private JTextField jtf;
    
    /** Creates a new instance of TestJTree2 */
    public TestJTree2()
    {
        jtf = new JTextField(15);
        jtf.setEditable(false);
        
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("MLB");
        DefaultMutableTreeNode al = new DefaultMutableTreeNode("American League");
        DefaultMutableTreeNode nl = new DefaultMutableTreeNode("National League");
        DefaultMutableTreeNode braves = new DefaultMutableTreeNode("Braves");
        DefaultMutableTreeNode mets = new DefaultMutableTreeNode("Mets");
        DefaultMutableTreeNode cardinals = new DefaultMutableTreeNode("Cardinals");
        DefaultMutableTreeNode rockies = new DefaultMutableTreeNode("Rockies");
        DefaultMutableTreeNode rangers = new DefaultMutableTreeNode("Rangers");
        DefaultMutableTreeNode twins = new DefaultMutableTreeNode("Twins");
        DefaultMutableTreeNode as = new DefaultMutableTreeNode("A's");
        DefaultMutableTreeNode whiteSox = new DefaultMutableTreeNode("White Sox");
        
        DefaultTreeModel dtm = new DefaultTreeModel(root);
        dtm.insertNodeInto(al, root, 0);
        dtm.insertNodeInto(nl, root, 1);
        dtm.insertNodeInto(braves, nl, 0);
        dtm.insertNodeInto(mets, nl, 1);
        dtm.insertNodeInto(cardinals, nl, 2);
        dtm.insertNodeInto(rockies, nl, 3);
        dtm.insertNodeInto(rangers, al, 0);
        dtm.insertNodeInto(twins, al, 1);
        dtm.insertNodeInto(as, al, 2);
        dtm.insertNodeInto(whiteSox, al, 3);
        
        tree1 = new JTree(dtm);
        tree1.setRootVisible(true);
        tree1.expandRow(1);

        
        tree1.addTreeSelectionListener(this);
        
        getContentPane().add(new JScrollPane(tree1),
                                 BorderLayout.CENTER);
        getContentPane().add(jtf, BorderLayout.SOUTH);
        
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 300, 300);
        setVisible(true);
        setTitle("Using a JTree");
    }
    
    public void valueChanged(TreeSelectionEvent tse)
    {
        DefaultMutableTreeNode dmtn = 
        (DefaultMutableTreeNode) tree1.getLastSelectedPathComponent();
        String name1 = (String) dmtn.getUserObject();
        jtf.setText("you selected: " + name1);
        jtf.setForeground(Color.black);
    }
    
    public static void main(String args[])
    {
        TestJTree2 tjt2 = new TestJTree2();
    }
}