Accordion Widget

[Timothy Sam]

Hi guys! Does anyone know where I can get an accordion widget? Something similar to this...

http://www.javaserver.org/jmaki/spry/plainAccordion.jsp

I've seen one in swing before in one of my previous companies but I forgot where they downloaded it. Thanks!

[Craig Wood]

These appear to be run by JavaScript.
Here's an idea of how you could build this in java.
It makes use of the Container method setComponentZOrder
which was introduced in j2se 1.5

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class AccordianTest {
    private JPanel getContent() {
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        panel.add(new AccordianPanel().getPanel(), gbc);
        return panel;
    }
 
    public static void main(String[] args) {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(new AccordianTest().getContent());
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}
 
class AccordianPanel extends JPanel {
    boolean movingComponents = false;
    int visibleIndex = 3;
 
    public AccordianPanel() {
        setLayout(null);
        // Add children and compute prefSize.
        int childCount = 4;
        Dimension d = new Dimension();
        int h = 0;
        for(int j = 0; j < childCount; j++) {
            ChildPanel child = new ChildPanel(j+1, ml);
            add(child);
            d = child.getPreferredSize();
            child.setBounds(0, h, d.width, d.height);
            if(j < childCount-1)
                h += ControlPanel.HEIGHT;
        }
        h += d.height;
        setPreferredSize(new Dimension(d.width, h));
        // Set z-order for children.
        setZOrder();
    }
 
    private void setZOrder() {
        Component[] c = getComponents();
        for(int j = 0; j < c.length-1; j++) {
            setComponentZOrder(c[j], c.length-1 - j);
        }
    }
 
    private void setChildVisible(int indexToOpen) {
        // If visibleIndex < indexToOpen, components at
        // [visibleIndex+1 down to indexToOpen] move up.
        // If visibleIndex > indexToOpen, components at
        // [indexToOpen+1 up to visibleIndex] move down.
        // Collect indices of components that will move
        // and determine the distance/direction to move.
        int[] indices = new int[0];
        int travelLimit = 0;
        if(visibleIndex < indexToOpen) {
            travelLimit = ControlPanel.HEIGHT -
                              getComponent(visibleIndex).getHeight();
            int n = indexToOpen - visibleIndex;
            indices = new int[n];
            for(int j = visibleIndex, k = 0; j < indexToOpen; j++, k++)
                indices[k] = j + 1;
        } else if(visibleIndex > indexToOpen) {
            travelLimit = getComponent(visibleIndex).getHeight() -
                              ControlPanel.HEIGHT;
            int n = visibleIndex - indexToOpen;
            indices = new int[n];
            for(int j = indexToOpen, k = 0; j < visibleIndex; j++, k++)
                indices[k] = j + 1;
        }
        movePanels(indices, travelLimit);
        visibleIndex = indexToOpen;
    }
 
    private void movePanels(final int[] indices, final int travel) {
        movingComponents = true;
        Thread thread = new Thread(new Runnable() {
            public void run() {
                Component[] c = getComponents();
                int limit = travel > 0 ? travel : 0;
                int count = travel > 0 ? 0 : travel;
                int dy    = travel > 0 ? 1 : -1;
                while(count < limit) {
                    try {
                        Thread.sleep(25);
                    } catch(InterruptedException e) {
                        System.out.println("interrupted");
                        break;
                    }
                    for(int j = 0; j < indices.length; j++) {
                        // The z-order reversed the order returned
                        // by getComponents. Adjust the indices to
                        // get the correct components to relocate.
                        int index = c.length-1 - indices[j];
                        Point p = c[index].getLocation();
                        p.y += dy;
                        c[index].setLocation(p.x, p.y);
                    }
                    repaint();
                    count++;
                }
                movingComponents = false;
            }
        });
        thread.setPriority(Thread.NORM_PRIORITY);
        thread.start();
    }
 
    private MouseListener ml = new MouseAdapter() {
        public void mousePressed(MouseEvent e) {
            int index = ((ControlPanel)e.getSource()).id-1;
            if(!movingComponents)
                setChildVisible(index);
        }
    };
 
    public JPanel getPanel() {
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        panel.setBorder(BorderFactory.createLineBorder(Color.black, 1));
        panel.add(this, gbc);
        return panel;
    }
}
 
class ChildPanel extends JPanel {
    public ChildPanel(int id, MouseListener ml) {
        setLayout(new BorderLayout());
        add(new ControlPanel(id, ml), "First");
        add(getContent(id));
    }
 
    private JPanel getContent(int id) {
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(2,2,2,2);
        gbc.weightx = 1.0;
        gbc.weighty = 1.0;
        gbc.anchor = gbc.NORTHWEST;
        panel.add(new JLabel("Panel " + id + " Content"), gbc);
        return panel;
    }
 
    public Dimension getPreferredSize() {
        return new Dimension(300,150);
    }
}
 
class ControlPanel extends JPanel {
    int id;
    JLabel titleLabel;
    Color c1 = new Color(200,180,180);
    Color c2 = new Color(200,220,220);
    Color fontFg = Color.blue;
    Color rolloverFg = Color.red;
    public final static int HEIGHT = 45;
 
    public ControlPanel(int id, MouseListener ml) {
        this.id = id;
        setLayout(new BorderLayout());
        add(titleLabel = new JLabel("Panel " + id, JLabel.CENTER));
        titleLabel.setForeground(fontFg);
        Dimension d = getPreferredSize();
        d.height = HEIGHT;
        setPreferredSize(d);
        addMouseListener(ml);
        addMouseListener(listener);
    }
 
    protected void paintComponent(Graphics g) {
        int w = getWidth();
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setPaint(new GradientPaint(w/2, 0, c1, w/2, HEIGHT/2, c2));
        g2.fillRect(0,0,w,HEIGHT);
    }
 
    private MouseListener listener = new MouseAdapter() {
        public void mouseEntered(MouseEvent e) {
            titleLabel.setForeground(rolloverFg);
        }
 
        public void mouseExited(MouseEvent e) {
            titleLabel.setForeground(fontFg);
        }
    };
}

[Mahesh Kedari]

Excellent Craig..!
Thanks a lot for this code...!!