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37
40
41 import java.util.*;
42 import java.awt.*;
43 import java.applet.Applet  ;
44 import java.awt.event.*;
45
46
47 class Node {
48 double x;
49 double y;
50
51 double dx;
52 double dy;
53
54 boolean fixed;
55
56 String lbl;
57 }
58
59
60 class Edge {
61 int from;
62 int to;
63
64 double len;
65 }
66
67
68 class GraphPanel extends Panel
69 implements Runnable , MouseListener, MouseMotionListener {
70 Graph graph;
71 int nnodes;
72 Node nodes[] = new Node[100];
73
74 int nedges;
75 Edge edges[] = new Edge[200];
76
77 Thread relaxer;
78 boolean stress;
79 boolean random;
80
81 int numMouseButtonsDown = 0;
82
83 GraphPanel(Graph graph) {
84 this.graph = graph;
85 addMouseListener(this);
86 }
87
88 int findNode(String lbl) {
89 for (int i = 0 ; i < nnodes ; i++) {
90 if (nodes[i].lbl.equals(lbl)) {
91 return i;
92 }
93 }
94 return addNode(lbl);
95 }
96 int addNode(String lbl) {
97 Node n = new Node();
98 n.x = 10 + 380*Math.random();
99 n.y = 10 + 380*Math.random();
100 n.lbl = lbl;
101 nodes[nnodes] = n;
102 return nnodes++;
103 }
104 void addEdge(String from, String to, int len) {
105 Edge e = new Edge();
106 e.from = findNode(from);
107 e.to = findNode(to);
108 e.len = len;
109 edges[nedges++] = e;
110 }
111
112 public void run() {
113 Thread me = Thread.currentThread();
114 while (relaxer == me) {
115 relax();
116 if (random && (Math.random() < 0.03)) {
117 Node n = nodes[(int)(Math.random() * nnodes)];
118 if (!n.fixed) {
119 n.x += 100*Math.random() - 50;
120 n.y += 100*Math.random() - 50;
121 }
122 graph.play(graph.getCodeBase(), "audio/drip.au");
123 }
124 try {
125 Thread.sleep(100);
126 } catch (InterruptedException e) {
127 break;
128 }
129 }
130 }
131
132 synchronized void relax() {
133 for (int i = 0 ; i < nedges ; i++) {
134 Edge e = edges[i];
135 double vx = nodes[e.to].x - nodes[e.from].x;
136 double vy = nodes[e.to].y - nodes[e.from].y;
137 double len = Math.sqrt(vx * vx + vy * vy);
138 len = (len == 0) ? .0001 : len;
139 double f = (edges[i].len - len) / (len * 3);
140 double dx = f * vx;
141 double dy = f * vy;
142
143 nodes[e.to].dx += dx;
144 nodes[e.to].dy += dy;
145 nodes[e.from].dx += -dx;
146 nodes[e.from].dy += -dy;
147 }
148
149 for (int i = 0 ; i < nnodes ; i++) {
150 Node n1 = nodes[i];
151 double dx = 0;
152 double dy = 0;
153
154 for (int j = 0 ; j < nnodes ; j++) {
155 if (i == j) {
156 continue;
157 }
158 Node n2 = nodes[j];
159 double vx = n1.x - n2.x;
160 double vy = n1.y - n2.y;
161 double len = vx * vx + vy * vy;
162 if (len == 0) {
163 dx += Math.random();
164 dy += Math.random();
165 } else if (len < 100*100) {
166 dx += vx / len;
167 dy += vy / len;
168 }
169 }
170 double dlen = dx * dx + dy * dy;
171 if (dlen > 0) {
172 dlen = Math.sqrt(dlen) / 2;
173 n1.dx += dx / dlen;
174 n1.dy += dy / dlen;
175 }
176 }
177
178 Dimension d = getSize();
179 for (int i = 0 ; i < nnodes ; i++) {
180 Node n = nodes[i];
181 if (!n.fixed) {
182 n.x += Math.max(-5, Math.min(5, n.dx));
183 n.y += Math.max(-5, Math.min(5, n.dy));
184 }
185 if (n.x < 0) {
186 n.x = 0;
187 } else if (n.x > d.width) {
188 n.x = d.width;
189 }
190 if (n.y < 0) {
191 n.y = 0;
192 } else if (n.y > d.height) {
193 n.y = d.height;
194 }
195 n.dx /= 2;
196 n.dy /= 2;
197 }
198 repaint();
199 }
200
201 Node pick;
202 boolean pickfixed;
203 Image offscreen;
204 Dimension offscreensize;
205 Graphics offgraphics;
206
207 final Color fixedColor = Color.red;
208 final Color selectColor = Color.pink;
209 final Color edgeColor = Color.black;
210 final Color nodeColor = new Color(250, 220, 100);
211 final Color stressColor = Color.darkGray;
212 final Color arcColor1 = Color.black;
213 final Color arcColor2 = Color.pink;
214 final Color arcColor3 = Color.red;
215
216 public void paintNode(Graphics g, Node n, FontMetrics fm) {
217 int x = (int)n.x;
218 int y = (int)n.y;
219 g.setColor((n == pick) ? selectColor : (n.fixed ? fixedColor : nodeColor));
220 int w = fm.stringWidth(n.lbl) + 10;
221 int h = fm.getHeight() + 4;
222 g.fillRect(x - w/2, y - h / 2, w, h);
223 g.setColor(Color.black);
224 g.drawRect(x - w/2, y - h / 2, w-1, h-1);
225 g.drawString(n.lbl, x - (w-10)/2, (y - (h-4)/2) + fm.getAscent());
226 }
227
228 public synchronized void update(Graphics g) {
229 Dimension d = getSize();
230 if ((offscreen == null) || (d.width != offscreensize.width) || (d.height != offscreensize.height)) {
231 offscreen = createImage(d.width, d.height);
232 offscreensize = d;
233 if (offgraphics != null) {
234 offgraphics.dispose();
235 }
236 offgraphics = offscreen.getGraphics();
237 offgraphics.setFont(getFont());
238 }
239
240 offgraphics.setColor(getBackground());
241 offgraphics.fillRect(0, 0, d.width, d.height);
242 for (int i = 0 ; i < nedges ; i++) {
243 Edge e = edges[i];
244 int x1 = (int)nodes[e.from].x;
245 int y1 = (int)nodes[e.from].y;
246 int x2 = (int)nodes[e.to].x;
247 int y2 = (int)nodes[e.to].y;
248 int len = (int)Math.abs(Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2)) - e.len);
249 offgraphics.setColor((len < 10) ? arcColor1 : (len < 20 ? arcColor2 : arcColor3)) ;
250 offgraphics.drawLine(x1, y1, x2, y2);
251 if (stress) {
252 String lbl = String.valueOf(len);
253 offgraphics.setColor(stressColor);
254 offgraphics.drawString(lbl, x1 + (x2-x1)/2, y1 + (y2-y1)/2);
255 offgraphics.setColor(edgeColor);
256 }
257 }
258
259 FontMetrics fm = offgraphics.getFontMetrics();
260 for (int i = 0 ; i < nnodes ; i++) {
261 paintNode(offgraphics, nodes[i], fm);
262 }
263 g.drawImage(offscreen, 0, 0, null);
264 }
265
266 public void mouseClicked(MouseEvent e) {
268 }
269
270 public void mousePressed(MouseEvent e) {
271 numMouseButtonsDown++;
272 addMouseMotionListener(this);
273 double bestdist = Double.MAX_VALUE;
274
275 int x = e.getX();
276 int y = e.getY();
277 for (int i = 0 ; i < nnodes ; i++) {
278 Node n = nodes[i];
279 double dist = (n.x - x) * (n.x - x) + (n.y - y) * (n.y - y);
280 if (dist < bestdist) {
281 pick = n;
282 bestdist = dist;
283 }
284 }
285 pickfixed = pick.fixed;
286 pick.fixed = true;
287 pick.x = x;
288 pick.y = y;
289
290 repaint();
291 e.consume();
292 }
293
294 public void mouseReleased(MouseEvent e) {
295 numMouseButtonsDown--;
296 removeMouseMotionListener(this);
297
298 pick.fixed = pickfixed;
299 pick.x = e.getX();
300 pick.y = e.getY();
301 if (numMouseButtonsDown == 0) {
302 pick = null;
303 }
304
305 repaint();
306 e.consume();
307 }
308
309 public void mouseEntered(MouseEvent e) {
310 }
311
312 public void mouseExited(MouseEvent e) {
313 }
314
315 public void mouseDragged(MouseEvent e) {
316 pick.x = e.getX();
317 pick.y = e.getY();
318 repaint();
319 e.consume();
320 }
321
322 public void mouseMoved(MouseEvent e) {
323 }
324
325 public void start() {
326 relaxer = new Thread (this);
327 relaxer.start();
328 }
329
330 public void stop() {
331 relaxer = null;
332 }
333
334 }
335
336
337 public class Graph extends Applet implements ActionListener, ItemListener {
338
339 GraphPanel panel;
340 Panel controlPanel;
341
342 Button scramble = new Button("Scramble");
343 Button shake = new Button("Shake");
344 Checkbox stress = new Checkbox("Stress");
345 Checkbox random = new Checkbox("Random");
346
347 public void init() {
348 setLayout(new BorderLayout());
349
350 panel = new GraphPanel(this);
351 add("Center", panel);
352 controlPanel = new Panel();
353 add("South", controlPanel);
354
355 controlPanel.add(scramble); scramble.addActionListener(this);
356 controlPanel.add(shake); shake.addActionListener(this);
357 controlPanel.add(stress); stress.addItemListener(this);
358 controlPanel.add(random); random.addItemListener(this);
359
360 String edges = getParameter("edges");
361 for (StringTokenizer t = new StringTokenizer(edges, ",") ; t.hasMoreTokens() ; ) {
362 String str = t.nextToken();
363 int i = str.indexOf('-');
364 if (i > 0) {
365 int len = 50;
366 int j = str.indexOf('/');
367 if (j > 0) {
368 len = Integer.valueOf(str.substring(j+1)).intValue();
369 str = str.substring(0, j);
370 }
371 panel.addEdge(str.substring(0,i), str.substring(i+1), len);
372 }
373 }
374 Dimension d = getSize();
375 String center = getParameter("center");
376 if (center != null){
377 Node n = panel.nodes[panel.findNode(center)];
378 n.x = d.width / 2;
379 n.y = d.height / 2;
380 n.fixed = true;
381 }
382 }
383
384 public void destroy() {
385 remove(panel);
386 remove(controlPanel);
387 }
388
389 public void start() {
390 panel.start();
391 }
392
393 public void stop() {
394 panel.stop();
395 }
396
397 public void actionPerformed(ActionEvent e) {
398 Object src = e.getSource();
399
400 if (src == scramble) {
401 play(getCodeBase(), "audio/computer.au");
402 Dimension d = getSize();
403 for (int i = 0 ; i < panel.nnodes ; i++) {
404 Node n = panel.nodes[i];
405 if (!n.fixed) {
406 n.x = 10 + (d.width-20)*Math.random();
407 n.y = 10 + (d.height-20)*Math.random();
408 }
409 }
410 return;
411 }
412
413 if (src == shake) {
414 play(getCodeBase(), "audio/gong.au");
415 Dimension d = getSize();
416 for (int i = 0 ; i < panel.nnodes ; i++) {
417 Node n = panel.nodes[i];
418 if (!n.fixed) {
419 n.x += 80*Math.random() - 40;
420 n.y += 80*Math.random() - 40;
421 }
422 }
423 }
424
425 }
426
427 public void itemStateChanged(ItemEvent e) {
428 Object src = e.getSource();
429 boolean on = e.getStateChange() == ItemEvent.SELECTED;
430 if (src == stress) panel.stress = on;
431 else if (src == random) panel.random = on;
432 }
433
434 public String getAppletInfo() {
435 return "Title: GraphLayout \nAuthor: <unknown>";
436 }
437
438 public String [][] getParameterInfo() {
439 String [][] info = {
440 {"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."},
441 {"center", "string", "The name of the center node."}
442 };
443 return info;
444 }
445
446 }
447
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