dynamictreedemo.java

初期JAVA学习非常有用的资料。帮助深入了解API。特别是Applet。

/*
 * This code is based on an example provided by Richard Stanford, 
 * a tutorial reader.
 */

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

public class DynamicTreeDemo extends JPanel {
    private int newNodeSuffix = 1;

    public DynamicTreeDemo(JFrame frame) {
        //create the components
        final DynamicTree treePanel = new DynamicTree();
        populateTree(treePanel);

        JButton addButton = new JButton("Add");
        addButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                treePanel.addObject("New Node " + newNodeSuffix++);
            }
        });

        JButton removeButton = new JButton("Remove");
        removeButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                treePanel.removeCurrentNode();
            }
        });

        JButton clearButton = new JButton("Clear");
        clearButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                treePanel.clear();
            }
        });

        //Lay everything out.
        setLayout(new BorderLayout());
        treePanel.setPreferredSize(new Dimension(300, 150));
        add(treePanel, BorderLayout.CENTER);

        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(0,1));
        panel.add(addButton);
        panel.add(removeButton);
        panel.add(clearButton);
        add(panel, BorderLayout.EAST);
    }

    public void populateTree(DynamicTree treePanel) {
        String p1Name = new String("Parent 1");
        String p2Name = new String("Parent 2");
        String c1Name = new String("Child 1");
        String c2Name = new String("Child 2");

        DefaultMutableTreeNode p1, p2;

        p1 = treePanel.addObject(null, p1Name);
        p2 = treePanel.addObject(null, p2Name);

        treePanel.addObject(p1, c1Name);
        treePanel.addObject(p1, c2Name);

        treePanel.addObject(p2, c1Name);
        treePanel.addObject(p2, c2Name);
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("DynamicTreeDemo");

        Container contentPane = frame.getContentPane();
        contentPane.setLayout(new GridLayout(1,1));
        contentPane.add(new DynamicTreeDemo(frame));

        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        frame.pack();
        frame.setVisible(true);
    }
}