Animation panel in another class

Question

hi all.
how can i play a smaller animation jpanel on a different class in a larger static jpanel/jframe?
the one that i did, did not animate.but it changes to its next frame each time i minimized/maximized the window.
how do i deal with that?
help...
thanks

Answer 1

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.*;
public class Animation implements Runnable
    AnimationPanel animationPanel;
    Thread animator;
    boolean animate;
    public Animation(AnimationPanel ap)
        animationPanel = ap;
        animate = false;
    public void run()
        while(animate)
            try
                Thread.sleep(40);
            catch(InterruptedException ie)
                System.err.println("interrupt: " + ie.getMessage());
                animate = false;
            animationPanel.moveBall();
    private void start()
        if(!animate)
            animate = true;
            animator = new Thread(this);
            animator.setPriority(Thread.NORM_PRIORITY);
            animator.start();
    private void stop()
        animate = false;
        animator = null;
    public static void main(String[] args)
        AnimationPanel animationPanel = new AnimationPanel();
        Animation test = new Animation(animationPanel);
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(test.getNorthPanel(), "North");
        f.getContentPane().add(animationPanel);
        f.getContentPane().add(test.getSouthPanel(), "South");
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
    private JPanel getNorthPanel()
        final JRadioButton
            x = new JRadioButton("dx", true),
            y = new JRadioButton("dy");
        ButtonGroup group = new ButtonGroup();
        group.add(x);
        group.add(y);
        final JSlider slider = new JSlider(JSlider.HORIZONTAL, 1, 3, 2);
        slider.setPaintTicks(true);
        slider.setMajorTickSpacing(1);
        slider.setPaintLabels(true);
        slider.addChangeListener(new ChangeListener()
            public void stateChanged(ChangeEvent e)
                int value = slider.getValue();
                if(x.isSelected())
                    animationPanel.dx = value;
                else
                    animationPanel.dy = value;
        JPanel panel = new JPanel();
        panel.setBorder(BorderFactory.createLoweredBevelBorder());
        panel.add(slider);
        panel.add(x);
        panel.add(y);
        return panel;
    private JPanel getSouthPanel()
        final JButton
            start = new JButton("start"),
            stop  = new JButton("stop");
        ActionListener l = new ActionListener()
            public void actionPerformed(ActionEvent e)
                JButton button = (JButton)e.getSource();
                if(button == start)
                    start();
                if(button == stop)
                    stop();
        start.addActionListener(l);
        stop.addActionListener(l);
        JPanel panel = new JPanel();
        panel.setBorder(BorderFactory.createLoweredBevelBorder());
        panel.add(start);
        panel.add(stop);
        return panel;
class AnimationPanel extends JPanel
    Ellipse2D ball;
    int dx, dy;
    final int DIAM = 16;
    public AnimationPanel()
        ball = new Ellipse2D.Double(50, 50, DIAM, DIAM);
        dx = 2;
        dy = 1;
    protected void paintComponent(Graphics g)
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setPaint(Color.red.darker());
        g2.fill(ball);
    public void moveBall()
        checkBoundries();
        double x = ball.getX() + dx;
        double y = ball.getY() + dy;
        ball.setFrameFromDiagonal(x, y, x+DIAM, y+DIAM);
        repaint();
    private void checkBoundries()
        if(ball.getX() + dx < 0 || ball.getX() + DIAM + dx > getWidth())
            dx *= -1;
        if(ball.getY() + dy < 0 || ball.getY() + DIAM + dy > getHeight())
            dy *= -1;
}