BufferedImageThread.java Source code

Introduction

Here is the source code for BufferedImageThread.java

Source

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class BufferedImageThread extends JFrame {
    AnimationCanvas canvas;

    JButton startButton, stopButton;

    public BufferedImageThread() {
        super();
        Container container = getContentPane();

        canvas = new AnimationCanvas();
        container.add(canvas);

        startButton = new JButton("Start Animation");
        startButton.addActionListener(new ButtonListener());
        stopButton = new JButton("Stop Animation");
        stopButton.addActionListener(new ButtonListener());
        JPanel panel = new JPanel();
        panel.add(startButton);
        panel.add(stopButton);
        container.add(BorderLayout.SOUTH, panel);

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        setSize(450, 425);
        setVisible(true);
    }

    class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            JButton temp = (JButton) e.getSource();

            if (temp.equals(startButton)) {
                canvas.start();
            } else if (temp.equals(stopButton)) {
                canvas.stop();
            }
        }
    }

    public static void main(String arg[]) {
        new BufferedImageThread();
    }
}

class AnimationCanvas extends JLabel implements Runnable {
    Thread thread;

    Image image;

    BufferedImage bi;

    double x, y, xi, yi;

    int rotate;

    double scale;

    int UP = 0;

    int DOWN = 1;

    int scaleDirection;

    AnimationCanvas() {
        setBackground(Color.green);
        setSize(450, 400);

        image = getToolkit().getImage("largeJava2sLogo.gif");

        MediaTracker mt = new MediaTracker(this);
        mt.addImage(image, 1);
        try {
            mt.waitForAll();
        } catch (Exception e) {
            System.out.println("Exception while loading image.");
        }

        if (image.getWidth(this) == -1) {
            System.out.println("No gif file");
            System.exit(0);
        }

        rotate = (int) (Math.random() * 360);
        scale = Math.random() * 1.5;
        scaleDirection = DOWN;

        xi = 50.0;
        yi = 50.0;

    }

    public void step(int w, int h) {
        x += xi;
        y += yi;

        if (x > w) {
            x = w - 1;
            xi = Math.random() * -w / 32;
        }
        if (x < 0) {
            x = 2;
            xi = Math.random() * w / 32;
        }
        if (y > h) {
            y = h - 2;
            yi = Math.random() * -h / 32;
        }
        if (y < 0) {
            y = 2;
            yi = Math.random() * h / 32;
        }

        if ((rotate += 5) == 360) {
            rotate = 0;
        }
        if (scaleDirection == UP) {
            if ((scale += 0.5) > 1.5) {
                scaleDirection = DOWN;
            }
        } else if (scaleDirection == DOWN) {
            if ((scale -= .05) < 0.5) {
                scaleDirection = UP;
            }
        }
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Dimension d = getSize();

        bi = new BufferedImage(d.width, d.height, BufferedImage.TYPE_INT_ARGB);
        Graphics2D big = bi.createGraphics();

        step(d.width, d.height);

        AffineTransform at = new AffineTransform();
        at.setToIdentity();
        at.translate(x, y);
        at.rotate(Math.toRadians(rotate));
        at.scale(scale, scale);
        big.drawImage(image, at, this);

        Graphics2D g2D = (Graphics2D) g;
        g2D.drawImage(bi, 0, 0, null);

        big.dispose();
    }

    public void start() {
        thread = new Thread(this);
        thread.setPriority(Thread.MIN_PRIORITY);
        thread.start();
    }

    public void stop() {
        if (thread != null)
            thread.interrupt();
        thread = null;
    }

    public void run() {
        Thread me = Thread.currentThread();
        while (thread == me) {
            repaint();
        }
        thread = null;
    }
}