cardtest.java

这是《Java 2 简明教程(第2版)》一书配套的源代码。

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;

class CardPanel extends Panel {
    ActionListener listener;

    Panel create(LayoutManager layout) {
Button b = null;
Panel p = new Panel();

p.setLayout(layout);

b = new Button("one");
b.addActionListener(listener);
p.add("North", b);

b = new Button("two");
b.addActionListener(listener);
p.add("West", b);

b = new Button("three");
b.addActionListener(listener);
p.add("South", b);

b = new Button("four");
b.addActionListener(listener);
p.add("East", b);

b = new Button("five");
b.addActionListener(listener);
p.add("Center", b);

b = new Button("six");
b.addActionListener(listener);
p.add("Center", b);

return p;
    }

    CardPanel(ActionListener actionListener) {
listener = actionListener;
setLayout(new CardLayout());
add("one", create(new FlowLayout()));
add("two", create(new BorderLayout()));
add("three", create(new GridLayout(2, 2)));
add("four", create(new BorderLayout(10, 10)));
add("five", create(new FlowLayout(FlowLayout.LEFT, 10, 10)));
add("six", create(new GridLayout(2, 2, 10, 10)));
    }

    public Dimension getPreferredSize() {
return new Dimension(200, 100);
    }
}

public class CardTest extends Applet
      implements ActionListener,
 ItemListener {
    CardPanel cards;

    public CardTest() {
setLayout(new BorderLayout());
add("Center", cards = new CardPanel(this));
Panel p = new Panel();
p.setLayout(new FlowLayout());
add("South", p);

Button b = new Button("first");
b.addActionListener(this);
p.add(b);

b = new Button("next");
b.addActionListener(this);
p.add(b);

b = new Button("previous");
b.addActionListener(this);
p.add(b);

b = new Button("last");
b.addActionListener(this);
p.add(b);

Choice c = new Choice();
c.addItem("one");
c.addItem("two");
c.addItem("three");
c.addItem("four");
c.addItem("five");
c.addItem("six");
c.addItemListener(this);
p.add(c);
    }

    public void itemStateChanged(ItemEvent e) {
((CardLayout)cards.getLayout()).show(cards,
                                     (String)(e.getItem()));
    }

    public void actionPerformed(ActionEvent e) {
String arg = e.getActionCommand();

if ("first".equals(arg)) {
    ((CardLayout)cards.getLayout()).first(cards);
} else if ("next".equals(arg)) {
    ((CardLayout)cards.getLayout()).next(cards);
} else if ("previous".equals(arg)) {
    ((CardLayout)cards.getLayout()).previous(cards);
} else if ("last".equals(arg)) {
    ((CardLayout)cards.getLayout()).last(cards);
} else {
    ((CardLayout)cards.getLayout()).show(cards,(String)arg);
}
    }

    public static void main(String args[]) {
Frame f = new Frame("CardTest");
CardTest cardTest = new CardTest();
cardTest.init();
cardTest.start();

f.add("Center", cardTest);
f.setSize(300, 300);
f.show();
    }
    
    public String getAppletInfo() {
        return "Demonstrates the different types of layout managers.";
    }
}