showloader.java

本书透彻讲解了经典的《设计模式：可复用面向对象软件的基础》一书涵盖的23种基本设计模式。本书将这些设计模式分成五类：接口型模式、责任型模式、构造型模式、操作型模式

package com.oozinoz.applications;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import com.oozinoz.ui.*;
import com.oozinoz.imaging.*;

/*
 * Copyright (c) 2001 Steven J. Metsker.
 * 
 * Steve Metsker makes no representations or warranties about
 * the fitness of this software for any particular purpose, 
 * including the implied warranty of merchantability.
 *
 * Please use this software as you wish with the sole
 * restriction that you may not claim that you wrote it.
 */
/**
 * Show the use of ImageIconLoader, a class that shows the
 * intent of the Proxy pattern without actually applying
 * the Proxy pattern. Rather than forwarding calls around,
 * this class just switches the image that is displayed.
 *
 * For this class to execute, an "images" directory must
 * be in the classpath, and this directory must contain
 * absent.jpg, loading.jpg, and fest.jpg.
 * 
 * @author Steven J. Metsker 
 */
public class ShowLoader implements ActionListener {
	private JFrame frame;
	private JButton loadButton;

/**
 * Start loading the image and disable the Load button.
 */
public void actionPerformed(ActionEvent e)
{
	loader.load(frame);
	loadButton().setEnabled(false);
}
protected JButton loadButton()
{
	if (loadButton == null)
	{
		loadButton = new JButton("Load");
		loadButton.addActionListener(this);
		loadButton.setFont(SwingFacade.getStandardFont());
	}
	return loadButton;
}
/**
 * Show the use of ImageIconLoader.
 */
public static void main(String[] args)
{
	ShowLoader sl = new ShowLoader();
	sl.frame = SwingFacade.launch(sl.mainPanel(), " Proxy");
}
protected JPanel mainPanel()
{
	JPanel p = new JPanel();
	p.setLayout(new BorderLayout());
	p.add("Center", new JLabel(loader));
	p.add("South", loadButton());
	return p;
}

	private ImageIconLoader loader =
		new ImageIconLoader("fest.jpg");
}