このJavaプログラム(WWWブラウザ内で動作するものは「アプレット」と言います)
の場合、たとえば下のようなプログラムとして記述して、これをJavaコンパイラ
というツールで変換して作成します。
import java.awt.*;
import java.applet.*;
import java.util.*;
import java.net.*;
public class koushin extends Applet implements Runnable {
Image imgs[];
int nimgs = 14;
int imgwidth;
int x, newx;
int dist = 5;
int timeout = 200;
Thread scroller;
public void init() {
newx = x = size().width;
imgs = new Image[nimgs];
for (int i = 0 ; i < nimgs ; i++) {
imgs[i] = getImage(getDocumentBase(), "GIF/B" + (i+1) + ".GIF");
}
setBackground(Color.black);
}
public void start() {
if (scroller == null) {
scroller = new Thread(this);
scroller.start();
}
}
public void stop() {
if (scroller != null) {
scroller.stop();
scroller = null;
}
}
public void run() {
while (true) {
try {Thread.currentThread().sleep(timeout);} catch (InterruptedException e){}
scroll(dist);
}
}
synchronized void scroll(int dist) {
newx += dist;
repaint();
}
public void update(Graphics g) {
if (newx != x) {
int dist = newx - x;
if (dist > 0) {
g.copyArea(1, 1, (size().width-2) - dist, size().height-2, dist, 0);
for (x = newx ; x > size().width ; x -= Math.max(size().width - 2, imgwidth));
paint(g, 1, dist + 1);
} else {
g.copyArea(1 - dist, 1, (size().width-2) + dist, size().height-2, dist, 0);
for (x = newx ; x < 0 ; x += Math.max(size().width - 2, imgwidth));
paint(g, (size().width-1) + dist, size().width-1);
}
} else {
paint(g);
}
}
public boolean imageUpdate(Image img, int flags, int x, int y, int w, int h) {
if ((flags & WIDTH) != 0) {
imgwidth += img.getWidth(this);
}
return super.imageUpdate(img, flags, x, y, w, h);
}
public void paint(Graphics g, int fromx, int tox) {
int x = this.x;
newx = x;
g.setColor(Color.black);
g.fillRect(fromx, 1, tox - fromx, size().height-2);
g.clipRect(fromx, 1, tox - fromx, size().height-2);
g.setColor(Color.black);
for (int i = 0 ; i < nimgs ; i++) {
if (imgs[i] == null) {
continue;
}
int w = imgs[i].getWidth(this);
int h = imgs[i].getHeight(this);
if ((w > 0) && (h > 0)) {
if ((x + w > fromx) && (x < tox)) {
g.drawImage(imgs[i], x, size().height - (h+10), this);
}
if ((x + w) > size().width) {
x -= Math.max(size().width - 2, imgwidth);
if ((x + w > fromx) && (x < tox)) {
g.drawImage(imgs[i], x, size().height - (h+10), this);
}
}
x += w;
}
}
}
public void paint(Graphics g) {
g.draw3DRect(0, 0, size().width, size().height, true);
paint(g, 1, size().width-1);
}
}
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