testjtree1.java

java2 primer plus一书源程序

/*
 * TestJTree1.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 TestJTree1 extends JFrame implements TreeSelectionListener
{
    private JTree tree1;
    private JTextField jtf;
    
    /** Creates a new instance of TestJTree1 */
    public TestJTree1()
    {
        jtf = new JTextField(15);
        jtf.setEditable(false);
        
        Object[] league = {"nl", "al"};
        
        Vector nlV = new Vector() 
        { 
            public String toString()
            {
                return "National League";
            }
        };
        
        nlV.addElement("Braves");
        nlV.addElement("Mets");
        nlV.addElement("Cardinals");
        nlV.addElement("Rockies" );

        
        Vector alV = new Vector() 
        { 
            public String toString()
            {
                return "American League";
            }
        };
        
        alV.addElement("Rangers");
        alV.addElement("Twins");
        alV.addElement("A's");
        alV.addElement("White Sox" );
        
        league[0] = nlV;
        league[1] = alV;

        tree1 = new JTree(league);
        tree1.setRootVisible(true);
        tree1.expandRow(0);

        
        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[])
    {
        TestJTree1 tjt1 = new TestJTree1();
    }
}