clientpropertiestest.java

《Java2图形设计卷II：Swing》配套光盘源码

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

public class ClientPropertiesTest extends JApplet {
	JButton button = new JButton("toggle target color");
	JComboBox targetCombo = new JComboBox();
	JPanel[] targets = { 	new JPanel(),
							new JPanel(),
							new JPanel() 	};
	public void init() {
		Container contentPane = getContentPane();
		Dimension targetPreferredSize = new Dimension(100,100);
		JPanel targetPanel = new JPanel();

		for(int i=0; i < targets.length; ++i) {
			targets[i].setBackground(Color.blue);
			targets[i].setPreferredSize(targetPreferredSize);
			targetPanel.add(targets[i]);

		}
		targetCombo.addItem("left");
		targetCombo.addItem("center");
		targetCombo.addItem("right");

		contentPane.setLayout(new FlowLayout());
		contentPane.add(button);
		contentPane.add(targetCombo);
		contentPane.add(targetPanel);

		button.putClientProperty("target", targets[0]);

		button.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				Component c = 
					(Component)button.getClientProperty("target");

				if(c != null) {
					Color bg = c.getBackground();

					c.setBackground(bg == Color.blue ?
									Color.red : Color.blue);

					c.repaint();
				}
			}
		});
		targetCombo.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				button.putClientProperty(
					"target", 
					targets[targetCombo.getSelectedIndex()]);
			}
		});
		button.addPropertyChangeListener(
									new PropertyChangeListener() {
			public void propertyChange(PropertyChangeEvent e) {
				if(e.getPropertyName().equals("target")) {
					showStatus(
						(String)targetCombo.getSelectedItem() + 
						" panel set as target");
				}
			}
		});
	}
	public static void main(String args[]) {
		final JFrame f = new JFrame();
		JApplet applet = new ClientPropertiesTest();

		applet.init();

		f.setContentPane(applet.getContentPane());
		f.setBounds(100,100,300,250);
		f.setTitle("ClientPropertiesTest");
		f.setVisible(true);

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