import javax.swing.*;import javax.swing.border.*;import javax.accessibility.*;import java.awt.*;import java.awt.event.*;/* * RootLayeredPaneDemo.java is a 1.4 application that requires * images/dukeWaveRed.gif. */public class RootLayeredPaneDemo extends JPanel                                 implements ActionListener,                                            MouseMotionListener {    private int[] layers = {-30000, 0, 301};    private String[] layerStrings = { "Yellow (-30000)",                                      "Magenta (0)",                                      "Cyan (301)" };    private Color[] layerColors = { Color.yellow,                                    Color.magenta,                                    Color.cyan };    private JLayeredPane layeredPane;    private JLabel dukeLabel;    private JCheckBox onTop;    private JComboBox layerList;    //Action commands    private static String ON_TOP_COMMAND = "ontop";    private static String LAYER_COMMAND = "layer";    //Adjustments to put Duke's toe at the cursor's tip.    private static final int XFUDGE = 40;    private static final int YFUDGE = 57;    //Initial layer of dukeLabel.    private static final int INITIAL_DUKE_LAYER_INDEX = 1;    public RootLayeredPaneDemo(JLayeredPane layeredPane)    {        super(new GridLayout(1,1));        //Create and load the duke icon.        final ImageIcon icon = createImageIcon("images/dukeWaveRed.gif");        //Create and set up the layered pane.        this.layeredPane = layeredPane;        layeredPane.addMouseMotionListener(this);        //This is the origin of the first label added.        Point origin = new Point(10, 100);        //This is the offset for computing the origin for the next label.        int offset = 35;        //Add several overlapping, colored labels to the layered pane        //using absolute positioning/sizing.        for (int i = 0; i < layerStrings.length; i++) {            JLabel label = createColoredLabel(layerStrings[i],                                              layerColors[i], origin);            layeredPane.add(label, new Integer(layers[i]));            origin.x += offset;            origin.y += offset;        }        //Create and add the Duke label to the layered pane.        dukeLabel = new JLabel(icon);        if (icon != null) {            dukeLabel.setBounds(15, 225,                                icon.getIconWidth(),                                icon.getIconHeight());        } else {            System.err.println("Duke icon not found; using black square instead.");            dukeLabel.setBounds(15, 225, 30, 30);            dukeLabel.setOpaque(true);            dukeLabel.setBackground(Color.BLACK);        }        layeredPane.add(dukeLabel,                        new Integer(layers[INITIAL_DUKE_LAYER_INDEX]),                        0);        //Add control pane to this JPanel.        add(createControlPanel());    }    /** Returns an ImageIcon, or null if the path was invalid. */    protected static ImageIcon createImageIcon(String path) {        java.net.URL imgURL = RootLayeredPaneDemo.class.getResource(path);        if (imgURL != null) {            return new ImageIcon(imgURL);        } else {            System.err.println("Couldn't find file: " + path);            return null;        }    }    //Create and set up a colored label.    private JLabel createColoredLabel(String text,                                      Color color,                                      Point origin) {        JLabel label = new JLabel(text);        label.setVerticalAlignment(JLabel.TOP);        label.setHorizontalAlignment(JLabel.CENTER);        label.setOpaque(true);        label.setBackground(color);        label.setForeground(Color.black);        label.setBorder(BorderFactory.createLineBorder(Color.black));        label.setBounds(origin.x, origin.y, 140, 140);        return label;    }    //Create the control pane for the top of the frame.    private JPanel createControlPanel() {        onTop = new JCheckBox("Top Position in Layer");        onTop.setSelected(true);        onTop.setActionCommand(ON_TOP_COMMAND);        onTop.addActionListener(this);        layerList = new JComboBox(layerStrings);        layerList.setSelectedIndex(INITIAL_DUKE_LAYER_INDEX);        layerList.setActionCommand(LAYER_COMMAND);        layerList.addActionListener(this);        JPanel controls = new JPanel();        controls.add(layerList);        controls.add(onTop);        controls.setBorder(BorderFactory.createTitledBorder(                                 "Choose Duke's Layer and Position"));        return controls;    }    //Make Duke follow the cursor.    public void mouseMoved(MouseEvent e) {        dukeLabel.setLocation(e.getX()-XFUDGE, e.getY()-YFUDGE);    }    public void mouseDragged(MouseEvent e) {} //do nothing    //Handle user interaction with the check box and combo box.    public void actionPerformed(ActionEvent e) {        String cmd = e.getActionCommand();        if (ON_TOP_COMMAND.equals(cmd)) {            if (onTop.isSelected())                layeredPane.moveToFront(dukeLabel);            else                layeredPane.moveToBack(dukeLabel);        } else if (LAYER_COMMAND.equals(cmd)) {            int position = onTop.isSelected() ? 0 : -1;            layeredPane.setLayer(dukeLabel,                                 layers[layerList.getSelectedIndex()],                                 position);        }    }    /**     * 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("RootLayeredPaneDemo");        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        //Create and set up the content pane.        RootLayeredPaneDemo newContentPane = new RootLayeredPaneDemo(          frame.getLayeredPane());        newContentPane.setOpaque(true); //content panes must be opaque        frame.setContentPane(newContentPane);        //Display the window.        frame.setSize(new Dimension(300, 350));        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();            }        });    }}