《Java2图形设计卷II：Swing》配套光盘源码

				import java.awt.*;
				import java.awt.event.*;
				import javax.swing.*;
				import javax.swing.event.*;
				
				public class Test extends JApplet {
					public Test() {
						Container contentPane = getContentPane();
						JViewport viewport = new JViewport();
						JPanel view = new JPanel();
				
						view.add(new JLabel(
									new ImageIcon("anjinAndMariko.gif")));
				
						viewport.setView(view);
				
						contentPane.add(new ControlPanel(viewport), 
										BorderLayout.NORTH);
						contentPane.add(viewport, BorderLayout.CENTER);
						contentPane.add(new StatusPanel(viewport),
										BorderLayout.SOUTH);
					}
				}
				class StatusPanel extends JPanel { 
					private JLabel extentLabel = new JLabel(),
									viewPositionLabel = new JLabel(),
									viewSizeLabel = new JLabel();
					private JViewport viewport;
				
					public StatusPanel(JViewport vp) {
						viewport = vp;
				
						setBorder(BorderFactory.createEtchedBorder());
						setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
				
						extentLabel.setAlignmentX(0.5f);
						viewPositionLabel.setAlignmentX(0.5f);
						viewSizeLabel.setAlignmentX(0.5f);
				
						add(extentLabel);
						add(viewPositionLabel);
						add(viewSizeLabel);
				
						viewport.addChangeListener(new ChangeListener() {
							public void stateChanged(ChangeEvent e) {
								Dimension extent = viewport.getExtentSize();
								Point viewPosition = viewport.getViewPosition();
								Rectangle viewSize = viewport.getViewRect();
				
								extentLabel.setText("View Extent: " + 
														extent.toString());
								viewPositionLabel.setText("View Position: " + 
														viewPosition.toString());
								viewSizeLabel.setText("View Size: " + 
													viewSize.toString());
								revalidate();
							}
						});
					}
				}
				class ControlPanel extends JPanel { 
					private JViewport viewport;
				
					private JButton[] buttons = {
						new JButton("up"), new JButton("down"),
						new JButton("left"), new JButton("right"),
					};
				
					public ControlPanel(JViewport vp) {
						viewport = vp;
				
						for(int i=0; i < buttons.length; ++i) {
							add(buttons[i]);
				
							buttons[i].addActionListener(new ActionListener() {
								public void actionPerformed(ActionEvent e) {
									scroll(e.getActionCommand());
								}
							});
						}
					}
					private void scroll(String actionCmd) {
						Point vp = viewport.getViewPosition();
				
						if(actionCmd.equals("up")) vp.y += 5;	
						else if(actionCmd.equals("down")) vp.y -= 5;	
						else if(actionCmd.equals("left")) vp.x += 5;	
						else if(actionCmd.equals("right")) vp.x -= 5;	
				
						viewport.setViewPosition(vp);
					}
				}