Please, help a newbie: Question about animating expanding containers

Question

Hi All,
Short Version of my Question:
I'm making a media player that needs to have an animation for panels sliding up and down and left and right, and the method I've been using to do this performs far slower than the speed I believe is possible, and required. What is a fast way to make a high performance animation for such an application?
Details:
So far, to do the animation, I've been using JSplitPanes and changing the position of the divider in a loop and calling paintImmediately or paintDirtyRegion like so:
public void animateDividerLocation( JSplitPane j, int to, int direction) {
for(int i=j.getDividerLocation(); i>=to; i-=JUMP_SIZE) {
j.setDividerLocation(i);
j.validate();
j.paintImmediately(0, 0, j.getWidth(), j.getHeight());
The validate and paintImmediately calls have been necessary to see any changes while the loop is going. I.e., if those calls are left out, the components appear to just skip right to where they were supposed to animate to, without having been animated at all.
The animation requirement is pretty simple. Basically, the application looks like it has 3 panels. One on the right, one on the left, and a toolbar at the bottom. The animation just needs to make the panels expand and contract.
Currenly, the animation only gets about, say, 4 frames a second on the 800 MHz Transmeta Crusoe processor, 114 MB Ram, Windows 2000 machine I must use (to approximate the performance of the processor I'll be using, which will run embedded Linux), even though I've taken most of the visible components out of the JPanels during the animation. I don't think this has to do with RAM reaching capacity, as the harddrive light does not light up often. Even if this were the case, the animation goes also goes slow (about 13 frames a second) on my 3 GHz P4 Windows XP if I keeps some JButtons, images etc., inside the JPanels. I get about 50 frames/sec on my 3 GHz P4, if I take most of the JButtons out, as I do for the 800 MHz processor. This is sufficient to animate the panels 400 pixels across the screen at 20 pixels per jump, but it isn't fast or smooth enough to animate across 400 pixels moving at 4 pixel jumps. I know 50 frames/sec is generally considered fast, but in this case, there is hardly anything changing on the screen (hardly any dirty pixels per new frame) and so I'd expect there to be some way to make the animation go much faster and smoother, since I've seen games and other application do much more much faster and much smoother.
I'm hoping someone can suggest a different, faster way to do the animation I require. Perhaps using the JSplitPane trick is not a good idea in terms of performance. Perhaps there are some tricks I can apply to my JSplitPane trick?
I haven't been using any fancy tricks - no double buffering, volatile images, canvas or other animation speed techniques. I haven't ever used any of those things as I'm fairly new to Swing and the 2D API. Actually I've read somewhere that Swing does double buffering without being told to, if I understood what I read. Is doing double buffering explicitly still required? And, if I do need to use double buffering or canvas or volatile images or anything else, I'm not sure how I would apply those techiniques to my problem, since I'm not animating a static image around the screen, but rather a set of containers (JSplitPanes and JPanels, mostly) and components (mostly JButtons) that often get re-adjusted or expanded as they are being animated. Do I need to get the Graphics object of the top container (would that contain the graphics objects for all the contained components?) and then double buffer, volatile image it, do the animation on a canvas, or something like that? Or what?
Thanks you SO much for any help!
Cortar
Related Issues(?) (Secondary concerns):
Although there are only three main panels, the actual number of GUI components I'm using, during the time of animation, is about 20 JPanels/JSplitPanes and 10 JButtons. Among the JPanels and the JSplitPanes, only a few JPanels are set to visible. I, for one, don't think this higher number of components is what is slowing me down, as I've tried taking out some components on my 3GHz machine and it didn't seem to affect performance much, if any. Am I wrong? Will minimizing components be among the necessary steps towards better performance?
Anyhow, the total number of JContainers that the application creates (mostly JPanels) is perhaps less than 100, and the total number of JComponents created (mostly JButtons and ImageIcons) is less than 200. The application somehow manages to use up 50 MBs RAM. Why? Without looking at the code, can anyone offer a FAQ type of answer to this?

Answer 1

You can comment out the lines that add buttons to the panels to see the behavior with empty panels.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.Timer;
public class DancingPanels
    static GridBagLayout gridbag = new GridBagLayout();
    static Timer timer;
    static int delay = 40;
    static int weightInc = 50;
    static boolean goLeft = false;
    public static void main(String[] args)
        final GridBagConstraints gbc = new GridBagConstraints();
        gbc.weightx = 1.0;
        gbc.weighty = 1.0;
        gbc.fill = gbc.HORIZONTAL;
        final JPanel leftPanel = new JPanel(gridbag);
        leftPanel.setBackground(Color.blue);
        gbc.insets = new Insets(0,30,0,30);
        leftPanel.add(new JButton("1"), gbc);
        leftPanel.add(new JButton("2"), gbc);
        final JPanel rightPanel = new JPanel(gridbag);
        rightPanel.setBackground(Color.yellow);
        gbc.insets = new Insets(30,50,30,50);
        gbc.gridwidth = gbc.REMAINDER;
        rightPanel.add(new JButton("3"), gbc);
        rightPanel.add(new JButton("4"), gbc);
        final JPanel panel = new JPanel(gridbag);
        gbc.fill = gbc.BOTH;
        gbc.insets = new Insets(0,0,0,0);
        gbc.gridwidth = gbc.RELATIVE;
        panel.add(leftPanel, gbc);
        gbc.gridwidth = gbc.REMAINDER;
        panel.add(rightPanel, gbc);
        timer = new Timer(delay, new ActionListener()
                gbc.fill = gbc.BOTH;
                gbc.gridwidth = 1;
            public void actionPerformed(ActionEvent e)
                double[] w = cycleWeights();
                gbc.weightx = w[0];
                gridbag.setConstraints(leftPanel, gbc);
                gbc.weightx = w[1];
                gridbag.setConstraints(rightPanel, gbc);
                panel.revalidate();
                panel.repaint();
        JFrame f = new JFrame("Dancing Panels");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(panel);
        f.setSize(400,300);
        f.setLocation(200,200);
        f.setVisible(true);
        timer.start();
    private static double[] cycleWeights()
        if(goLeft)
            weightInc--;
        else
            weightInc++;
        if(weightInc > 100)
            weightInc = 100;
            goLeft = true;
        if(weightInc < 0)
            weightInc = 0;
            goLeft = false;
        double wLeft = weightInc/ 100.0;
        double wRight = (100 - weightInc)/100.0;
        return new double[]{wLeft, wRight};
}