// Written by Walter Piechulla in August 1998 for project "Wissensmanagement im Studium" // based on code from Sun // Written with Microsoft Visual J++ version 1.1 // (which is based on the 1.0.2 version of JDK) import java.util.*; import java.awt.*; import java.net.*; import java.applet.Applet; class Node { double x; double y; double dx; double dy; boolean fixed; boolean nurOrientierung; String lbl; String relativeURL; // relativ zu getDocumentBase } class Edge { int from; int to; double len; } class GraphPanel extends Panel implements Runnable { graph graphObj; int nnodes; Node nodes[] = new Node[100]; int nedges; Edge edges[] = new Edge[200]; Thread relaxer; boolean stress; boolean random = true; GraphPanel(graph graphObj) { this.graphObj = graphObj; } int findNode(String lbl,String relativeURL) { for(int i=0; i < nnodes;i++) { if (nodes[i].lbl.equals(lbl)) { return i; } } return addNode(lbl,relativeURL); } int addNode(String lbl,String relativeURL) { Node n = new Node(); n.x = 10 + 380*Math.random(); n.y = 10 + 380*Math.random(); n.lbl = lbl; n.relativeURL = relativeURL; nodes[nnodes] = n; // Wenn der String nur aus Versalien besteht, dann ist das nur ein Orientierungsknoten int strLen = lbl.length(); n.nurOrientierung = true; for(int i=0;i < strLen;i++) { if (Character.isLowerCase(lbl.charAt(i))) { n.nurOrientierung = false; break; } } return nnodes++; } void addEdge(String from,String to,String relativeURL,int len) { Edge e = new Edge(); e.from = findNode(from,relativeURL); e.to = findNode(to,relativeURL); e.len = len; edges[nedges++] = e; } public void run() { while (true) { 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; } graphObj.play(graphObj.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); 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(); 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 = size(); 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)); //System.out.println("v= " + n.dx + "," + 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; final Color fixedColor = Color.red; final Color selectColor = Color.pink; final Color edgeColor = Color.black; final Color nodeColor = Color.white; final Color stressColor = Color.gray; final Color arcColor1 = Color.white; final Color arcColor2 = Color.pink; final Color arcColor3 = Color.red; Color orientierung; // Wird in init() nach Applet-Parameter angelegt public void paintNode(Graphics g,Node n,FontMetrics fm) { int x = (int)n.x; int y = (int)n.y; if (n.nurOrientierung) { g.setColor(orientierung); // kann nicht angeklickt werden } else { g.setColor((n == pick) ? selectColor : (n.fixed ? fixedColor : nodeColor)); } int w = fm.stringWidth(n.lbl) + 10; int h = fm.getHeight() + 4; g.fillRect(x - w/2, y - h / 2, w, h); g.setColor(Color.black); g.drawRect(x - w/2, y - h / 2, w-1, h-1); g.drawString(n.lbl, x - (w-10)/2, (y - (h-4)/2) + fm.getAscent()); } public synchronized void update(Graphics g) { Dimension d = size(); if ((offscreen == null) || (d.width != offscreensize.width) || (d.height != offscreensize.height)) { offscreen = createImage(d.width, d.height); offscreensize = d; 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); } public synchronized boolean mouseDown(Event evt,int x,int y) { double bestdist = Double.MAX_VALUE; 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; } } if (evt.clickCount == 2) // Doppelklick { if (pick.nurOrientierung) // kein wählbarer Knoten { graphObj.play(graphObj.getCodeBase(), "audio/drip.au"); } else // Öffne ein Browserfenster { try { URL url = graphObj.getDocumentBase(); URL completeURL = new URL(url,pick.relativeURL); graphObj.getAppletContext().showDocument(completeURL,"_self"); } catch (MalformedURLException e) { graphObj.play(graphObj.getCodeBase(), "audio/drip.au"); } } } pickfixed = pick.fixed; pick.fixed = true; pick.x = x; pick.y = y; repaint(); return true; } public synchronized boolean mouseDrag(Event evt, int x, int y) { pick.x = x; pick.y = y; repaint(); return true; } public synchronized boolean mouseUp(Event evt, int x, int y) { pick.x = x; pick.y = y; pick.fixed = pickfixed; pick = null; repaint(); return true; } public void start() { relaxer = new Thread(this); relaxer.start(); } public void stop() { relaxer.stop(); } } public class graph extends Applet { GraphPanel panel; public void init() { setLayout(new BorderLayout()); panel = new GraphPanel(this); add("Center", panel); Panel p = new Panel(); add("South", p); p.add(new Button("Vermischen")); p.add(new Button("Schütteln")); //p.add(new Checkbox("Spannung")); //p.add(new Checkbox("Zufall")); String basiccolor = getParameter("basiccolor"); StringTokenizer t0 = new StringTokenizer(basiccolor, ","); String strR = t0.nextToken(); String strG = t0.nextToken(); String strB = t0.nextToken(); panel.orientierung = new Color(Integer.parseInt(strR),Integer.parseInt(strG),Integer.parseInt(strB)); String edges = getParameter("edges"); for (StringTokenizer t = new StringTokenizer(edges, ",") ; t.hasMoreTokens() ; ) { String str = t.nextToken(); int i = str.indexOf('-'); int k = str.indexOf('@'); if (i > 0) { int len = 50; int j = str.indexOf('\\'); // Der backslash. Original war das /, aber das brauche ich in den URLs, also: \ if (j > 0) { len = Integer.valueOf(str.substring(j+1)).intValue(); str = str.substring(0,j); } if (k > 0) // Eine URL für ein Dokument am Ende des Tokens { panel.addEdge(str.substring(0,i),str.substring(i+1,k),str.substring(k+1),len); } else // Keine URL { panel.addEdge(str.substring(0,i),str.substring(i+1),"Noth",len); } } } Dimension d = size(); String center = getParameter("center"); if (center != null) { Node n = panel.nodes[panel.findNode(center,"Noth")]; n.x = d.width / 2; n.y = d.height / 2; n.fixed = true; } setBackground(Color.black); } public void start() { panel.start(); } public void stop() { panel.stop(); } public boolean action(Event evt,Object arg) { //if (arg instanceof Boolean) //{ // if (((Checkbox)evt.target).getLabel().equals("Spannung")) // { // panel.stress = ((Boolean)arg).booleanValue(); // } // else // { // panel.random = ((Boolean)arg).booleanValue(); // } // // return true; //} if ("Vermischen".equals(arg)) { play(getCodeBase(), "audio/computer.au"); Dimension d = size(); 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 true; } if ("Schütteln".equals(arg)) { play(getCodeBase(), "audio/gong.au"); Dimension d = size(); 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; } } return true; } return false; } }