framedemo2.java

这是一个英文版的《Java程序设计与问题解决》现在好多大学都当成教材

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

/*
 * FrameDemo2.java is a 1.4 example that shows off the window decoration
 * features added in 1.4, plus some window positioning code.
 * It requires no other files.
 */
public class FrameDemo2 extends WindowAdapter
                        implements ActionListener {
    private Point lastLocation = null;
    private int maxX = 500;
    private int maxY = 500;

    //constants for action commands
    protected static String NO_DECORATIONS = "no_dec";
    protected static String LF_DECORATIONS = "laf_dec";
    protected static String WS_DECORATIONS = "ws_dec";
    protected static String CREATE_WINDOW = "new_win";

    //true if the next frame created should have no window decorations
    protected boolean noDecorations = false;

    //Perform some initialization.
    public FrameDemo2() {
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        maxX = screenSize.width - 50;
        maxY = screenSize.height - 50;
    }

    //Create a new MyFrame object and show it.
    public void showNewWindow() {
        JFrame frame = new MyFrame();

        //Take care of the no window decorations case.
        //NOTE: Unless you really need the functionality
        //provided by JFrame, you would usually use a
        //Window or JWindow instead.
        if (noDecorations) {
            frame.setUndecorated(true);
        }

        //Set window location.
        if (lastLocation != null) {
            //Move the window over and down 40 pixels.
            lastLocation.translate(40, 40);
            if ((lastLocation.x > maxX) || (lastLocation.y > maxY)) {
                lastLocation.setLocation(0, 0);
            }
            frame.setLocation(lastLocation);
        } else {
            lastLocation = frame.getLocation();
        }

        //Show window.
        frame.setSize(new Dimension(170, 100));
        frame.setVisible(true);
    }

    // Create the window-creation controls that go in the main window.
    protected JComponent createOptionControls() {
        JLabel label = new JLabel("Options for subsequently created frames:");
        ButtonGroup bg = new ButtonGroup();

        //Create the buttons
        JRadioButton rb1 = new JRadioButton();
        rb1.setText("Look and feel decorated");
        rb1.setActionCommand(LF_DECORATIONS);
        rb1.addActionListener(this);
        rb1.setSelected(true);
        bg.add(rb1);
        //
        JRadioButton rb2 = new JRadioButton();
        rb2.setText("Window system decorated");
        rb2.setActionCommand(WS_DECORATIONS);
        rb2.addActionListener(this);
        bg.add(rb2);
        //
        JRadioButton rb3 = new JRadioButton();
        rb3.setText("No decorations");
        rb3.setActionCommand(NO_DECORATIONS);
        rb3.addActionListener(this);
        bg.add(rb3);

        //Add everything to a container.
        javax.swing.Box box = Box.createVerticalBox();
        box.add(label);
        box.add(Box.createVerticalStrut(5)); //spacer
        box.add(rb1);
        box.add(rb2);
        box.add(rb3);

        //Add some breathing room.
        box.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));

        return box;
    }

    //Create the button that goes in the main window.
    protected JComponent createButtonPane() {
        JButton button = new JButton("New window");
        button.setActionCommand(CREATE_WINDOW);
        button.addActionListener(this);

        //Center the button in a panel with some space around it.
        JPanel pane = new JPanel();
        pane.setLayout(new FlowLayout());
        pane.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
        pane.add(button);

        return pane;
    }

    //Handle action events from all the buttons.
    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();

        //Handle the New window button.
        if (CREATE_WINDOW.equals(command)) {
            showNewWindow();

        //Handle the radio buttons.
        } else if (NO_DECORATIONS.equals(command)) {
            noDecorations = true;
            JFrame.setDefaultLookAndFeelDecorated(false);
        } else if (WS_DECORATIONS.equals(command)) {
            noDecorations = false;
            JFrame.setDefaultLookAndFeelDecorated(false);
        } else if (LF_DECORATIONS.equals(command)) {
            noDecorations = false;
            JFrame.setDefaultLookAndFeelDecorated(true);
        }
    }

    //Start the demo.
    public static void main(String[] args) {
        FrameDemo2 demo = new FrameDemo2();

        //Make sure we have nice window decorations.
        JFrame.setDefaultLookAndFeelDecorated(true);
        JDialog.setDefaultLookAndFeelDecorated(true);

        //Create the main window.
        JFrame frame = new JFrame("FrameDemo2");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Add components to it.
        Container contentPane = frame.getContentPane();
        contentPane.add(demo.createOptionControls(),
                        BorderLayout.CENTER);
        contentPane.add(demo.createButtonPane(),
                        BorderLayout.PAGE_END);

        //Display the window.
        frame.pack();
        frame.setLocationRelativeTo(null); //center it
        frame.setVisible(true);
    }

    class MyFrame extends JFrame implements ActionListener {

        //Create a frame with a button.
        public MyFrame() {
            super("A window");
            setDefaultCloseOperation(DISPOSE_ON_CLOSE);

            //This button lets you close even an undecorated window.
            JButton button = new JButton("Close window");
            button.addActionListener(this);

            //Place the button near the bottom of the window.
            Container contentPane = getContentPane();
            contentPane.setLayout(new BoxLayout(contentPane,
                                                BoxLayout.Y_AXIS));
            contentPane.add(Box.createVerticalGlue()); //takes all extra space
            contentPane.add(button);
            button.setAlignmentX(Component.CENTER_ALIGNMENT); //horizontally centered
            contentPane.add(Box.createVerticalStrut(5)); //spacer
        }

        //Make the button do the same thing as the default close operation
        //(DISPOSE_ON_CLOSE).
        public void actionPerformed(ActionEvent e) {
            setVisible(false);
            dispose();
        }
    }
}