Javaの課題丸投げコミュのappletからapplicationへの変換について

現在javaのサンプルプログラムの中のGraphLayout をいじっているのですがappletのコードからapplicationのコードに変換したいと考えてるのですがうまくいかないので質問させてもらいました。
環境はjava5.0を利用しています。
変換する際にSWINGを使ってボタン等の記述を変えたいのですが教えてください。
（サンプルのソースから少しいじってあります）

import java.util.*;
import java.awt.*;
import java.applet.Applet;
import java.awt.event.*;


class Node {
double x; //nodeのx座標
double y; //nodeのy座標

double dx;
double dy;

boolean fixed;

String lbl;
}

class Edge {
int from;
int to;

double len;
}

class GraphPanel extends Panel
implements Runnable, MouseListener, MouseMotionListener {
/**
*
*/
private static final long serialVersionUID = 1L;
Graph graph;
int nnodes;
Node nodes[] = new Node[1000];

int nedges;
Edge edges[] = new Edge[1000];

Thread relaxer;
boolean stress;

int numMouseButtonsDown = 0;

GraphPanel(Graph graph) {
this.graph = graph;
addMouseListener(this);
}

int findNode(String lbl) {
for (int i = 0 ; i < nnodes ; i++) {
if (nodes[i].lbl.equals(lbl)) {
return i;
}
}
return addNode(lbl);
}

int addNode(String lbl) {
Node n = new Node();
n.x = 10 + 380*Math.random();
n.y = 10 + 380*Math.random();
n.lbl = lbl;
nodes[nnodes] = n;
return nnodes++;
}
void addEdge(String from, String to, int len) {
Edge e = new Edge();
e.from = findNode(from);
e.to = findNode(to);
e.len = len;
edges[nedges++] = e;
}

public void run() {
Thread me = Thread.currentThread();
while (relaxer == me) {
relax();
if (random && (Math.random() < 0.03)) {
Node n = nodes[(int)(Math.random() * nnodes)];
if (!n.fixed) {
n.x += 100*Math.random() - 50;
n.y += 100*Math.random() - 50;
}
graph.play(graph.getCodeBase(), "audio/drip.au");
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {
break;
}
}
}

synchronized void relax() {
for (int i = 0 ; i < nedges ; i++) {
Edge e = edges[i];
double vx = nodes[e.to].x - nodes[e.from].x;
double vy = nodes[e.to].y - nodes[e.from].y;
double len = Math.sqrt(vx * vx + vy * vy);
len = (len == 0) ? .0001 : len;
double f = (edges[i].len - len) / (len * 3);
double dx = f * vx;
double dy = f * vy;

nodes[e.to].dx += dx;
nodes[e.to].dy += dy;
nodes[e.from].dx += -dx;
nodes[e.from].dy += -dy;
}

for (int i = 0 ; i < nnodes ; i++) {
Node n1 = nodes[i];
double dx = 0;
double dy = 0;

for (int j = 0 ; j < nnodes ; j++) {
if (i == j) {
continue;
}
Node n2 = nodes[j];
double vx = n1.x - n2.x;
double vy = n1.y - n2.y;
double len = vx * vx + vy * vy;
if (len == 0) {
dx += Math.random(); //random=0.0~1.0
dy += Math.random();
} else if (len < 100*100) {
dx += vx / len;
dy += vy / len;
}
}
double dlen = dx * dx + dy * dy;
if (dlen > 0) {
dlen = Math.sqrt(dlen) / 2;
n1.dx += dx / dlen;
n1.dy += dy / dlen;
}
}

Dimension d = getSize();
for (int i = 0 ; i < nnodes ; i++) {
Node n = nodes[i];
if (!n.fixed) {
n.x += Math.max(-5, Math.min(5, n.dx));
n.y += Math.max(-5, Math.min(5, n.dy));
}
if (n.x < 0) {
n.x = 0;
} else if (n.x > d.width) {
n.x = d.width;
}
if (n.y < 0) {
n.y = 0;
} else if (n.y > d.height) {
n.y = d.height;
}
n.dx /= 2;
n.dy /= 2;
}
repaint();
}

Node pick;
boolean pickfixed;
Image offscreen;
Dimension offscreensize;
Graphics offgraphics;

//rootノードの色設定
final Color fixedColor = Color.red;
//マウスで選択したときの色
final Color selectColor = Color.pink;
//
final Color edgeColor = Color.black;
//nodeの色設定
//final Color nodeColor = new Color(250, 220, 100);
final Color nodeColor1 = Color.green;
final Color nodeColor2 = Color.blue;
final Color nodeColor3 = Color.gray;
final Color nodeColor4 = Color.magenta;
final Color nodeColor5 = Color.orange;
final Color nodeColor6 = Color.yellow;
final Color nodeColor7 = Color.cyan;
final Color nodeColor8 = Color.red;

//node間の線の色の設定
final Color stressColor = Color.darkGray;
final Color arcColor1 = Color.black;
final Color arcColor2 = Color.pink;
final Color arcColor3 = Color.red;

public void paintNode(Graphics g, Node n, FontMetrics fm) {
int x = (int)n.x;
int y = (int)n.y;

//nodeの色設定
//nodeColorに条件分岐で色を指定

g.setColor((n == pick) ? selectColor : (n.fixed ? fixedColor : nodeColor1));


int w = 15;
int h = 15;

g.fillOval(x - w/2, y - h / 2, w, h);



g.setColor(Color.black);

g.drawOval(x - w/2, y - h / 2, w-1, h-1);

//idの表示(選択したもの)
if(n == pick){
g.drawString(n.lbl, x - (w-10)/2, (y - (h-4)/2) + fm.getAscent() - 15);
}

}

public synchronized void update(Graphics g) {
Dimension d = getSize();
if ((offscreen == null) || (d.width != offscreensize.width) || (d.height != offscreensize.height)) {
offscreen = createImage(d.width, d.height);
offscreensize = d;
if (offgraphics != null) {
offgraphics.dispose();
}
offgraphics = offscreen.getGraphics();
offgraphics.setFont(getFont());
}

offgraphics.setColor(getBackground());
offgraphics.fillRect(0, 0, d.width, d.height);
for (int i = 0 ; i < nedges ; i++) {
Edge e = edges[i];
int x1 = (int)nodes[e.from].x;
int y1 = (int)nodes[e.from].y;
int x2 = (int)nodes[e.to].x;
int y2 = (int)nodes[e.to].y;
int len = (int)Math.abs(Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2)) - e.len);

offgraphics.setColor((len < 10) ? arcColor1 : (len < 20 ? arcColor2 : arcColor3)) ;


//offgraphics.drawLine(x1, y1, x2, y2);

if (stress) {

String lbl = String.valueOf(len);
offgraphics.setColor(stressColor);
offgraphics.drawString(lbl, x1 + (x2-x1)/2, y1 + (y2-y1)/2);
offgraphics.setColor(edgeColor);
}
}

FontMetrics fm = offgraphics.getFontMetrics();
for (int i = 0 ; i < nnodes ; i++) {
paintNode(offgraphics, nodes[i], fm);
}
g.drawImage(offscreen, 0, 0, null);
}

//1.1 event handling
public void mouseClicked(MouseEvent e) {
}

public void mousePressed(MouseEvent e) {
numMouseButtonsDown++;
addMouseMotionListener(this);
double bestdist = Double.MAX_VALUE;

int x = e.getX();
int y = e.getY();
for (int i = 0 ; i < nnodes ; i++) {
Node n = nodes[i];
double dist = (n.x - x) * (n.x - x) + (n.y - y) * (n.y - y);
if (dist < bestdist) {
pick = n;
bestdist = dist;
}
}
pickfixed = pick.fixed;
pick.fixed = true;
pick.x = x;
pick.y = y;

repaint();
e.consume();
}

public void mouseReleased(MouseEvent e) {
numMouseButtonsDown--;
removeMouseMotionListener(this);

pick.fixed = pickfixed;
pick.x = e.getX();
pick.y = e.getY();
if (numMouseButtonsDown == 0) {
pick = null;
}

repaint();
e.consume();
}

public void mouseEntered(MouseEvent e) {
}

public void mouseExited(MouseEvent e) {
}

public void mouseDragged(MouseEvent e) {
pick.x = e.getX();
pick.y = e.getY();
repaint();
e.consume();
}

public void mouseMoved(MouseEvent e) {
}

public void start() {
relaxer = new Thread(this);
relaxer.start();
}

public void stop() {
relaxer = null;
}

}


public class Graph extends Applet implements ActionListener, ItemListener {

/**
*
*/
private static final long serialVersionUID = 1L;
GraphPanel panel;
Panel controlPanel;

Button scramble = new Button("Scramble");
Button shake = new Button("Shake");
Checkbox stress = new Checkbox("Stress");

public void init() {
setLayout(new BorderLayout());

panel = new GraphPanel(this);
add("Center", panel);
controlPanel = new Panel();
add("South", controlPanel);

controlPanel.add(scramble); scramble.addActionListener(this);
controlPanel.add(shake); shake.addActionListener(this);
controlPanel.add(stress); stress.addItemListener(this);

//パラメータの取得
String edges = getParameter("edges");
for (StringTokenizer t = new StringTokenizer(edges, ",") ; t.hasMoreTokens() ; ) {
String str = t.nextToken();
int i = str.indexOf('-');
if (i > 0) {
int len = 50;
int j = str.indexOf('/');
if (j > 0) {
len = Integer.valueOf(str.substring(j+1)).intValue();
str = str.substring(0, j);
}
panel.addEdge(str.substring(0,i), str.substring(i+1), len);
}
}

//rootの配置
Dimension d = getSize();
String center = getParameter("center");
if (center != null){
Node n = panel.nodes[panel.findNode(center)];
n.x = d.width / 2;
n.y = d.height / 2;
n.fixed = true;
}
}

public void destroy() {
remove(panel);
remove(controlPanel);
}

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

public void stop() {
panel.stop();
}

public void actionPerformed(ActionEvent e) {
Object src = e.getSource();

if (src == scramble) {
//play(getCodeBase(), "audio/computer.au");
Dimension d = getSize();
for (int i = 0 ; i < panel.nnodes ; i++) {
Node n = panel.nodes[i];
if (!n.fixed) {
n.x = 10 + (d.width-20)*Math.random();
n.y = 10 + (d.height-20)*Math.random();
}
}
return;
}

if (src == shake) {
//play(getCodeBase(), "audio/gong.au");
Dimension d = getSize();
for (int i = 0 ; i < panel.nnodes ; i++) {
Node n = panel.nodes[i];
if (!n.fixed) {
n.x += 80*Math.random() - 40;
n.y += 80*Math.random() - 40;
}
}
}

}

public void itemStateChanged(ItemEvent e) {
Object src = e.getSource();
boolean on = e.getStateChange() == ItemEvent.SELECTED;
if (src == stress) panel.stress = on;
}

public String getAppletInfo() {
return "Title: GraphLayout \nAuthor: <unknown>";
}

public String[][] getParameterInfo() {
String[][] info = {
{"edges", "delimited string", "A comma-delimited list of all the edges. It takes the form of 'C-N1,C-N2,C-N3,C-NX,N1-N2/M12,N2-N3/M23,N3-NX/M3X,...' where C is the name of center node (see 'center' parameter) and NX is a node attached to the center node. For the edges connecting nodes to each other (and not to the center node) you may (optionally) specify a length MXY separated from the edge name by a forward slash."},
{"center", "string", "The name of the center node."}
};
return info;
}

}