Swing animation running extremely slow

Question

I have a problem with my current animation that I\'m running using Java Swing. It is a discrete event simulation and the text based simulation is working fine, I\'m just hav

Answer 1

Based on this previous answer, the example below simulates a fleet of three cabs moving randomly on a rectangular grid. A javax.swing.Timer drives the animation at 5 Hz. The model and view are tightly coupled in CabPanel, but the animation may provide some useful insights. In particular, you might increase the number of cabs or lower the timer delay.

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;

/**
 * @see https://stackoverflow.com/a/14887457/230513
 * @see https://stackoverflow.com/questions/5617027
 */

public class FleetPanel extends JPanel {

    private static final Random random = new Random();
    private final MapPanel map = new MapPanel();
    private final JPanel control = new JPanel();
    private final List fleet = new ArrayList();
    private final Timer timer = new Timer(200, null);

    public FleetPanel() {
        super(new BorderLayout());
        fleet.add(new CabPanel("Cab #1", Hue.Cyan));
        fleet.add(new CabPanel("Cab #2", Hue.Magenta));
        fleet.add(new CabPanel("Cab #3", Hue.Yellow));
        control.setLayout(new GridLayout(0, 1));
        for (CabPanel cp : fleet) {
            control.add(cp);
            timer.addActionListener(cp.listener);
        }
        this.add(map, BorderLayout.CENTER);
        this.add(control, BorderLayout.SOUTH);
    }

    public void start() {
        timer.start();
    }

    private class CabPanel extends JPanel {

        private static final String format = "000000";
        private final DecimalFormat df = new DecimalFormat(format);
        private JLabel name = new JLabel("", JLabel.CENTER);
        private Point point = new Point();
        private JLabel position = new JLabel(toString(point), JLabel.CENTER);
        private int blocks;
        private JLabel odometer = new JLabel(df.format(0), JLabel.CENTER);
        private final JComboBox colorBox = new JComboBox();
        private final JButton reset = new JButton("Reset");
        private final ActionListener listener = new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                int ds = random.nextInt(3) - 1;
                if (random.nextBoolean()) {
                    point.x += ds;
                } else {
                    point.y += ds;
                }
                blocks += Math.abs(ds);
                update();
            }
        };

        public CabPanel(String s, Hue hue) {
            super(new GridLayout(1, 0));
            name.setText(s);
            this.setBackground(hue.getColor());
            this.add(map, BorderLayout.CENTER);
            for (Hue h : Hue.values()) {
                colorBox.addItem(h);
            }
            colorBox.setSelectedIndex(hue.ordinal());
            colorBox.addActionListener(new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent e) {
                    Hue h = (Hue) colorBox.getSelectedItem();
                    CabPanel.this.setBackground(h.getColor());
                    update();
                }
            });
            reset.addActionListener(new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent e) {
                    point.setLocation(0, 0);
                    blocks = 0;
                    update();
                }
            });
            this.add(name);
            this.add(odometer);
            this.add(position);
            this.add(colorBox);
            this.add(reset);
        }

        private void update() {
            position.setText(CabPanel.this.toString(point));
            odometer.setText(df.format(blocks));
            map.repaint();
        }

        private String toString(Point p) {
            StringBuilder sb = new StringBuilder();
            sb.append(Math.abs(p.x));
            sb.append(p.x < 0 ? " W" : " E");
            sb.append(", ");
            sb.append(Math.abs(p.y));
            sb.append(p.y < 0 ? " N" : " S");
            return sb.toString();
        }
    }

    private class MapPanel extends JPanel {

        private static final int SIZE = 16;

        public MapPanel() {
            this.setPreferredSize(new Dimension(32 * SIZE, 32 * SIZE));
            this.setBackground(Color.lightGray);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g;
            g2d.setRenderingHint(
                RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);
            int w = this.getWidth();
            int h = this.getHeight();
            g2d.setColor(Color.gray);
            for (int col = SIZE; col <= w; col += SIZE) {
                g2d.drawLine(col, 0, col, h);
            }
            for (int row = SIZE; row <= h; row += SIZE) {
                g2d.drawLine(0, row, w, row);
            }

            for (CabPanel cp : fleet) {
                Point p = cp.point;
                int x = SIZE * (p.x + w / 2 / SIZE) - SIZE / 2;
                int y = SIZE * (p.y + h / 2 / SIZE) - SIZE / 2;
                g2d.setColor(cp.getBackground());
                g2d.fillOval(x, y, SIZE, SIZE);
            }
        }
    }

    public enum Hue {

        Cyan(Color.cyan), Magenta(Color.magenta), Yellow(Color.yellow),
        Red(Color.red), Green(Color.green), Blue(Color.blue),
        Orange(Color.orange), Pink(Color.pink);
        private final Color color;

        private Hue(Color color) {
            this.color = color;
        }

        public Color getColor() {
            return color;
        }
    }

    private static void display() {
        JFrame f = new JFrame("Dispatch");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        FleetPanel fp = new FleetPanel();
        f.add(fp);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
        fp.start();
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                display();
            }
        });
    }
}