framework.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.JFrame;
import javax.swing.JMenuBar;
import javax.swing.JMenu;
import javax.swing.JMenuItem;

import javax.swing.JOptionPane;

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

public class Framework extends WindowAdapter {
    public int numWindows = 0;
    private Point lastLocation = null;
    private int maxX = 500;
    private int maxY = 500;

    public Framework() {
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        maxX = screenSize.width - 50; 
        maxY = screenSize.height - 50; 
        makeNewWindow();
    } 

    public void makeNewWindow() {
        JFrame frame = new MyFrame(this);
        numWindows++;
        System.out.println("Number of windows: " + numWindows);

        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();
        }

        System.out.println("Frame location: " + lastLocation);
        frame.setVisible(true);
    }

    //This method must be evoked from the event-dispatching thread.
    public void quit(JFrame frame) {
        if (quitConfirmed(frame)) {
            System.out.println("Quitting.");
            System.exit(0);
        }
        System.out.println("Quit operation not confirmed; staying alive.");
    }

    private boolean quitConfirmed(JFrame frame) {
        String s1 = "Quit";
        String s2 = "Cancel";
        Object[] options = {s1, s2};
        int n = JOptionPane.showOptionDialog(frame,
                "Windows are still open.\nDo you really want to quit?",
                "Quit Confirmation",
                JOptionPane.YES_NO_OPTION,
                JOptionPane.QUESTION_MESSAGE,
                null,
                options,
                s1);
        if (n == JOptionPane.YES_OPTION) {
            return true;
        } else {
            return false;
        }
    }

    public void windowClosed(WindowEvent e) {
        numWindows--;
        System.out.println("Number of windows = " + numWindows);
        if (numWindows <= 0) {
            System.out.println("All windows gone.  Bye bye!");
            System.exit(0);
        }
    }

    public static void main(String[] args) {
        Framework framework = new Framework();
    }
}

class MyFrame extends JFrame {
    protected Dimension defaultSize = new Dimension(200, 200);
    protected Framework framework = null;

    public MyFrame(Framework controller) {
        super("New Frame");
        framework = controller;
        setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        addWindowListener(framework);

        JMenu menu = new JMenu("Window");
        menu.setMnemonic(KeyEvent.VK_W);
        JMenuItem item = null;
        //close
        item = new JMenuItem("Close");
        item.setMnemonic(KeyEvent.VK_C);
        item.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.out.println("Close window");
                MyFrame.this.setVisible(false);
                MyFrame.this.dispose();
            }
        });
        menu.add(item);

        //new
        item = new JMenuItem("New");
        item.setMnemonic(KeyEvent.VK_N);
        item.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.out.println("New window");
                framework.makeNewWindow();
            }
        });
        menu.add(item);

        //quit
        item = new JMenuItem("Quit");
        item.setMnemonic(KeyEvent.VK_Q);
        item.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.out.println("Quit request");
                framework.quit(MyFrame.this);
            }
        });
        menu.add(item);

        JMenuBar menuBar = new JMenuBar();
        menuBar.add(menu);
        setJMenuBar(menuBar);

        setSize(defaultSize);
    }
}