dialogdemo.java

这是一个用java编写的关于GUI应用编程的简单的样例

package chap13.demo;

import javax.swing.JOptionPane;
import javax.swing.JDialog;
import javax.swing.JButton;
import javax.swing.JRadioButton;
import javax.swing.ButtonGroup;
import javax.swing.JLabel;
import javax.swing.ImageIcon;
import javax.swing.BoxLayout;
import javax.swing.Box;
import javax.swing.BorderFactory;
import javax.swing.border.Border;
import javax.swing.JTabbedPane;
import javax.swing.JPanel;
import javax.swing.JFrame;
import java.beans.*; //Property change stuff
import java.awt.*;
import java.awt.event.*;

/*
 * DialogDemo.java is a 1.4 application that requires these files:
 *   CustomDialog.java
 *   images/middle.gif
 */
public class DialogDemo extends JPanel {
    JLabel label;
    ImageIcon icon = createImageIcon("images/middle.gif");
    JFrame frame;
    String simpleDialogDesc = "Some simple message dialogs";
    String iconDesc = "A JOptionPane has its choice of icons";
    String moreDialogDesc = "Some more dialogs";
    CustomDialog customDialog;

    /** Creates the GUI shown inside the frame's content pane. */
    public DialogDemo(JFrame frame) {
        super(new BorderLayout());
        this.frame = frame;
        customDialog = new CustomDialog(frame, "geisel", this);
        customDialog.pack();

        //Create the components.
        JPanel frequentPanel = createSimpleDialogBox();
        JPanel featurePanel = createFeatureDialogBox();
        JPanel iconPanel = createIconDialogBox();
        label = new JLabel("Click the \"Show it!\" button"
                           + " to bring up the selected dialog.",
                           JLabel.CENTER);

        //Lay them out.
        Border padding = BorderFactory.createEmptyBorder(20,20,5,20);
        frequentPanel.setBorder(padding);
        featurePanel.setBorder(padding);
        iconPanel.setBorder(padding);

        JTabbedPane tabbedPane = new JTabbedPane();
        tabbedPane.addTab("Simple Modal Dialogs", null,
                          frequentPanel,
                          simpleDialogDesc); //tooltip text
        tabbedPane.addTab("More Dialogs", null,
                          featurePanel,
                          moreDialogDesc); //tooltip text
        tabbedPane.addTab("Dialog Icons", null,
                          iconPanel,
                          iconDesc); //tooltip text

        add(tabbedPane, BorderLayout.CENTER);
        add(label, BorderLayout.PAGE_END);
        label.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
    }

    /** Sets the text displayed at the bottom of the frame. */
    void setLabel(String newText) {
        label.setText(newText);
    }

    /** Returns an ImageIcon, or null if the path was invalid. */
    protected static ImageIcon createImageIcon(String path) {
        java.net.URL imgURL = DialogDemo.class.getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL);
        } else {
            System.err.println("Couldn't find file: " + path);
            return null;
        }
    }

    /** Creates the panel shown by the first tab. */
    private JPanel createSimpleDialogBox() {
        final int numButtons = 4;
        JRadioButton[] radioButtons = new JRadioButton[numButtons];
        final ButtonGroup group = new ButtonGroup();

        JButton showItButton = null;

        final String defaultMessageCommand = "default";
        final String yesNoCommand = "yesno";
        final String yeahNahCommand = "yeahnah";
        final String yncCommand = "ync";

        radioButtons[0] = new JRadioButton("OK (in the L&F's words)");
        radioButtons[0].setActionCommand(defaultMessageCommand);

        radioButtons[1] = new JRadioButton("Yes/No (in the L&F's words)");
        radioButtons[1].setActionCommand(yesNoCommand);

        radioButtons[2] = new JRadioButton("Yes/No "
                      + "(in the programmer's words)");
        radioButtons[2].setActionCommand(yeahNahCommand);

        radioButtons[3] = new JRadioButton("Yes/No/Cancel "
                           + "(in the programmer's words)");
        radioButtons[3].setActionCommand(yncCommand);

        for (int i = 0; i < numButtons; i++) {
            group.add(radioButtons[i]);
        }
        radioButtons[0].setSelected(true);

        showItButton = new JButton("Show it!");
        showItButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String command = group.getSelection().getActionCommand();

                //ok dialog
                if (command == defaultMessageCommand) {
                    JOptionPane.showMessageDialog(frame,
                                "Eggs aren't supposed to be green.");

                //yes/no dialog
                } else if (command == yesNoCommand) {
                    int n = JOptionPane.showConfirmDialog(
                            frame, "Would you like green eggs and ham?",
                            "An Inane Question",
                            JOptionPane.YES_NO_OPTION);
                    if (n == JOptionPane.YES_OPTION) {
                        setLabel("Ewww!");
                    } else if (n == JOptionPane.NO_OPTION) {
                        setLabel("Me neither!");
                    } else {
                        setLabel("Come on -- tell me!");
                    }

                //yes/no (not in those words)
                } else if (command == yeahNahCommand) {
                    Object[] options = {"Yes, please", "No way!"};
                    int n = JOptionPane.showOptionDialog(frame,
                                    "Would you like green eggs and ham?",
                                    "A Silly Question",
                                    JOptionPane.YES_NO_OPTION,
                                    JOptionPane.QUESTION_MESSAGE,
                                    null,
                                    options,
                                    options[0]);
                    if (n == JOptionPane.YES_OPTION) {
                        setLabel("You're kidding!");
                    } else if (n == JOptionPane.NO_OPTION) {
                        setLabel("I don't like them, either.");
                    } else {
                        setLabel("Come on -- 'fess up!");
                    }

                //yes/no/cancel (not in those words)
                } else if (command == yncCommand) {
                    Object[] options = {"Yes, please",
                                        "No, thanks",
                                        "No eggs, no ham!"};
                    int n = JOptionPane.showOptionDialog(frame,
                                    "Would you like some green eggs to go "
                                    + "with that ham?",
                                    "A Silly Question",
                                    JOptionPane.YES_NO_CANCEL_OPTION,
                                    JOptionPane.QUESTION_MESSAGE,
                                    null,
                                    options,
                                    options[2]);
                    if (n == JOptionPane.YES_OPTION) {
                        setLabel("Here you go: green eggs and ham!");
                    } else if (n == JOptionPane.NO_OPTION) {
                        setLabel("OK, just the ham, then.");
                    } else if (n == JOptionPane.CANCEL_OPTION) {
                        setLabel("Well, I'm certainly not going to eat them!");
                    } else {
                        setLabel("Please tell me what you want!");
                    }
                }
                return;
            }
        });

        return createPane(simpleDialogDesc + ":",
                          radioButtons,
                          showItButton);
    }

    /**
     * Used by createSimpleDialogBox and createFeatureDialogBox
     * to create a pane containing a description, a single column
     * of radio buttons, and the Show it! button.
     */
    private JPanel createPane(String description,
                              JRadioButton[] radioButtons,
                              JButton showButton) {

        int numChoices = radioButtons.length;
        JPanel box = new JPanel();
        JLabel label = new JLabel(description);

        box.setLayout(new BoxLayout(box, BoxLayout.PAGE_AXIS));
        box.add(label);

        for (int i = 0; i < numChoices; i++) {
            box.add(radioButtons[i]);
        }

        JPanel pane = new JPanel(new BorderLayout());
        pane.add(box, BorderLayout.PAGE_START);
        pane.add(showButton, BorderLayout.PAGE_END);
        return pane;
    }

    /**
     * Like createPane, but creates a pane with 2 columns of radio
     * buttons.  The number of buttons passed in *must* be even.
     */
     private JPanel create2ColPane(String description,
                                  JRadioButton[] radioButtons,
                                  JButton showButton) {
        JLabel label = new JLabel(description);
        int numPerColumn = radioButtons.length/2;

        JPanel grid = new JPanel(new GridLayout(0, 2));
        for (int i = 0; i < numPerColumn; i++) {
            grid.add(radioButtons[i]);
            grid.add(radioButtons[i + numPerColumn]);
        }

        JPanel box = new JPanel();
        box.setLayout(new BoxLayout(box, BoxLayout.PAGE_AXIS));
        box.add(label);
        grid.setAlignmentX(0.0f);
        box.add(grid);

        JPanel pane = new JPanel(new BorderLayout());
        pane.add(box, BorderLayout.PAGE_START);
        pane.add(showButton, BorderLayout.PAGE_END);

        return pane;
    }

    /*
     * Creates the panel shown by the 3rd tab.
     * These dialogs are implemented using showMessageDialog, but
     * you can specify the icon (using similar code) for any other
     * kind of dialog, as well.
     */
    private JPanel createIconDialogBox() {
        JButton showItButton = null;

        final int numButtons = 6;
        JRadioButton[] radioButtons = new JRadioButton[numButtons];
        final ButtonGroup group = new ButtonGroup();

        final String plainCommand = "plain";
        final String infoCommand = "info";
        final String questionCommand = "question";
        final String errorCommand = "error";
        final String warningCommand = "warning";
        final String customCommand = "custom";

        radioButtons[0] = new JRadioButton("Plain (no icon)");
        radioButtons[0].setActionCommand(plainCommand);

        radioButtons[1] = new JRadioButton("Information icon");
        radioButtons[1].setActionCommand(infoCommand);

        radioButtons[2] = new JRadioButton("Question icon");
        radioButtons[2].setActionCommand(questionCommand);

        radioButtons[3] = new JRadioButton("Error icon");
        radioButtons[3].setActionCommand(errorCommand);

        radioButtons[4] = new JRadioButton("Warning icon");
        radioButtons[4].setActionCommand(warningCommand);

        radioButtons[5] = new JRadioButton("Custom icon");
        radioButtons[5].setActionCommand(customCommand);

        for (int i = 0; i < numButtons; i++) {
            group.add(radioButtons[i]);
        }
        radioButtons[0].setSelected(true);

        showItButton = new JButton("Show it!");
        showItButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String command = group.getSelection().getActionCommand();

                //no icon
                if (command == plainCommand) {
                    JOptionPane.showMessageDialog(frame,