focusexample.java

java swing 开发代码

//  FocusExample.java
// An example of focus traversal using the keyboard to navigate through a
// small set of buttons.
//
package	jswing.ch28;

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class FocusExample extends JFrame {

    public FocusExample() {

        super("Focus Example");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        MyPanel mypanel = new MyPanel();

        JButton  button1 = new JButton("One");
        JButton  button2 = new JButton("Two");
        JButton  button3 = new JButton("Three");
        JButton button4 = new JButton("Four");
        JButton button5 = new MyButton("Five*");
        JButton  button6 = new MyButton("Six*");
        JButton  button7 = new JButton("Seven");

        mypanel.add(button2);
        mypanel.add(button3);

        JInternalFrame frame1 = new JInternalFrame("Internal Frame 1",
                                                   true, true, true, true);
 
        frame1.setBackground(Color.lightGray);
        frame1.getContentPane().setLayout(new GridLayout(2, 3));
        frame1.setSize(300, 200);

        frame1.getContentPane().add(button1);
        frame1.getContentPane().add(mypanel);
        frame1.getContentPane().add(button4);
        frame1.getContentPane().add(button5);
        frame1.getContentPane().add(button6);
        frame1.getContentPane().add(button7);

        JDesktopPane desktop = new JDesktopPane();
        desktop.add(frame1, new Integer(1));
        desktop.setOpaque(true);

        //  Now set up the user interface window.
        Container contentPane = getContentPane();
        contentPane.add(desktop, BorderLayout.CENTER);
        setSize(new Dimension(400, 300));
        frame1.setVisible(true);
        setVisible(true);
    }

    public static void main(String[] args) {
        new FocusExample();
    }

    class MyButton extends JButton {
        public MyButton(String s) { super(s); }
        public boolean isFocusable() { return false; }
    }

    class MyPanel extends JPanel {
        public MyPanel() {
            super(true);
            java.util.Set upKeys = new java.util.HashSet(1);
            upKeys.add(AWTKeyStroke.getAWTKeyStroke(KeyEvent.VK_UP, 0));
            setFocusTraversalKeys(KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS,
                                  upKeys);
        }
        public boolean isFocusCycleRoot() { return true; }
    }
}