/* * BoxLayoutDemo2.java is a 1.4 application that requires one other * file:  BLDComponent.java */import java.awt.*;import java.awt.event.*;import javax.swing.*;public class BoxLayoutDemo2 implements ItemListener {    protected static int NUM_COMPONENTS = 3;    protected static float[] xAlignment = {                                 Component.LEFT_ALIGNMENT,                                 Component.CENTER_ALIGNMENT,                                 Component.RIGHT_ALIGNMENT};    protected static float[] hue = {0.0f, 0.33f, 0.67f};    protected static boolean restrictSize = true;    protected static boolean sizeIsRandom = false;    protected static BLDComponent[] bldComponent =        new BLDComponent[NUM_COMPONENTS];    public void populateContentPane(Container contentPane) {        JPanel panel = new JPanel();        panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));        //Create the rectangles.        int shortSideSize = 15;        for (int i = 0; i < NUM_COMPONENTS; i++) {            if (sizeIsRandom) {                shortSideSize = (int)(30.0 * Math.random()) + 30;            } else {                shortSideSize += 10;            }            bldComponent[i] = new BLDComponent(xAlignment[i], hue[i],                                               shortSideSize,                                               restrictSize,                                               sizeIsRandom,                                               String.valueOf(i));            panel.add(bldComponent[i]);        }        //Create the instructions.        JLabel label = new JLabel("Click a rectangle to "                                + "change its X alignment.");        JCheckBox cb = new JCheckBox("Restrict maximum rectangle size.");        cb.setSelected(restrictSize);        cb.addItemListener(this);        panel.setBorder(BorderFactory.createLineBorder(Color.red));        Box box = Box.createVerticalBox();        box.add(label);        box.add(cb);        contentPane.add(panel, BorderLayout.CENTER);        contentPane.add(box, BorderLayout.PAGE_END);    }    public void itemStateChanged(ItemEvent e) {        if (e.getStateChange() == ItemEvent.SELECTED) {            restrictSize = true;        } else {            restrictSize = false;        }        notifyBLDComponents();    }    static public void notifyBLDComponents() {        for (int i = 0; i < NUM_COMPONENTS; i++) {            bldComponent[i].setSizeRestriction(restrictSize);        }        bldComponent[0].revalidate();    }    /**     * Create the GUI and show it.  For thread safety,     * this method should be invoked from the     * event-dispatching thread.     */    private static void createAndShowGUI() {        //Make sure we have nice window decorations.        JFrame.setDefaultLookAndFeelDecorated(true);        //Create and set up the window.        JFrame frame = new JFrame("BoxLayoutDemo2");        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        //Create and set up the content pane.        BoxLayoutDemo2 demo = new BoxLayoutDemo2();        demo.populateContentPane(frame.getContentPane());        //Display the window.        frame.pack();        frame.setVisible(true);    }    public static void main(String[] args) {        //Schedule a job for the event-dispatching thread:        //creating and showing this application's GUI.        javax.swing.SwingUtilities.invokeLater(new Runnable() {            public void run() {                createAndShowGUI();            }        });    }}