使用技巧：Java中使用Draw2D和SWT绘图 （2）

1. public void plot(){ 
2.     //if no place to plot, or no data to plot, return. 
3.     if(null==_parent || null==_seriesData) 
4.         return; 
5. 
6.     Composite composite = new Composite(_parent, SWT.BORDER); 
7.     composite.setLayout(new FillLayout()); 
8.     FigureCanvas canvas = new FigureCanvas(composite); 
9.      
10.     Panel contents = new Panel();//A Panel is a general purpose container figure 
11.     contents.setLayoutManager(new XYLayout()); 
12.     initializeSpan(contents.getClientArea()); 
13.      
14.     populateNodesAndEdges();      
15.      
16.     drawAxis(contents); 
17.     for(int i=0; i<_numSeries; i++){ 
18.      drawDotsAndConnections(contents,getDirectedGraph(i)); //  
draw points & connecting wires 
19.     } 
20.     canvas.setContents(contents); 
21. }

//This is a sample, you will need to add actual Node(s) to this NodeList. 
NodeList nodes = new NodeList(); //create a list of nodes. 
//This is a sample, you will need to add actual Edge(s) to this EdgeList. 
EdgeList edges = new EdgeList(); //create a list of edges.  
DirectedGraph graph = new DirectedGraph(); 
graph.nodes = nodes; 
graph.edges = edges; 
new BreakCycles().visit(graph);//ask BreakCycles to visit the graph. 
//now our "graph" is ready to be used.

private void populateNodesAndEdges(){ 
      
    _seriesScaledValues = new ArrayList(getScaledValues(_seriesData)); 
  _nodeLists = new ArrayList(); 
  _edgeLists = new ArrayList(); 
   
  for(int i=0; i<_numSeries; i++){ 
   _nodeLists.add(new NodeList());// one NodeList per series. 
   _edgeLists.add(new EdgeList());// one EdgeList per series. 
  } 
  //populate all NodeLists with the Nodes.  
  for(int i=0; i<_numSeries; i++){//for each series 
   double data[] = (double[])_seriesData.get(i);//get the series 
   int xCoOrds[] = getXCoordinates(_seriesData); 
   int yCoOrds[] = getYCoordinates(i, data); 
   //each NodeList has as many Nodes as points in a series 
   for(int j=0; j<data.length; j++){ 
    Double doubleValue = new Double(data[j]); 
    Node node = new Node(doubleValue); 
    node.x = xCoOrds[j]; 
    node.y = yCoOrds[j];     
    ((NodeList)_nodeLists.get(i)).add(node); 
   }      
  } 
  //populate all EdgeLists with the Edges.  
  for(int i=0; i<_numSeries; i++){ 
   NodeList nodes = (NodeList)_nodeLists.get(i);    
   for(int j=0; j<nodes.size()-1; j++){ 
    Node leftNode = nodes.getNode(j); 
    Node rightNode = nodes.getNode(j+1); 
    Edge edge = new Edge(leftNode,rightNode); 
    edge.start = new Point(leftNode.x, leftNode.y);  
    edge.end = new Point(rightNode.x, rightNode.y); 
    ((EdgeList)_edgeLists.get(i)).add(edge); 
   }  
  } 
  int breakpoint = 0; 
 }

private void drawDotsAndConnections(IFigure contents, DirectedGraph graph){ 
     for (int i = 0; i < graph.nodes.size(); i++) { 
         Node node = graph.nodes.getNode(i); 
         drawNode(contents, node); 
     } 
     for (int i = 0; i < graph.edges.size(); i++) { 
         Edge edge = graph.edges.getEdge(i); 
         drawEdge(contents, edge); 
     }   
 } 
  
 private void drawNode(IFigure contents, Node node){ 
   Dot dotFigure = new Dot(); 
   node.data = dotFigure; 
   int xPos = node.x; 
   int yPos = node.y;   
   contents.add(dotFigure); 
   contents.setConstraint(dotFigure, new Rectangle(xPos,yPos,-1,-1)); 
 } 
  
 private void drawEdge(IFigure contents, Edge edge){ 
     PolylineConnection wireFigure = new PolylineConnection(); 
  //edge.source is the Node to the left of this edge 
     EllipseAnchor sourceAnchor = new EllipseAnchor((Dot)edge.source.data); 

  //edge.target is the Node to the right of this edge 
  EllipseAnchor targetAnchor = new EllipseAnchor((Dot)edge.target.data); 
     wireFigure.setSourceAnchor(sourceAnchor); 
     wireFigure.setTargetAnchor(targetAnchor); 
     contents.add(wireFigure);      
 }