在Java中使用Draw2D和SWT绘图

 

 private ArrayList dataGenerator() { 

  double series1[] = new double[5];  

      for(int i=0; i<series1.length; i++) 

       series1[i] = (i*10) + 10; // a linear  

       series containing 10,20,30,40,50 

       

      double series2[] = new double[9];  

      series2[0] = 20; series2[1] = 150; series2[2] = 5; 

      series2[3] = 90; series2[4] = 35;  series2[5] = 20; 

                            series2[6] = 150; series2[7] = 5; series2[8] = 45; 

       

      double series3[] = new double[7];  

      for(int i=0; i<series3.length; i++) 

       series3[i] = (i*20) + 15; 

      

      seriesData.add(series1); 

      seriesData.add(series2); 

      seriesData.add(series3);  

                 return seriesData; 

 } 

FigureCanvas

Draw2D 中的 FigureCanvas 是 SWT Canvas 的一个扩展。FigureCanvas 可以包含 Draw2D 图形。

Panel

Panel 是 Draw2D 中的一个通用容器图形，它可以包含子图形。您可以向一个 Panel 图形中添加许多图形，然后将这个 Panel 图形提供给 FigureCanvas。

DirectedGraph

DirectedGraph 是一个 2-D 图形，拥有有限数量的 Node，每个 Node 都位于一些 Point 中，相邻的 Node 是通过 Edges 彼此连接在一起的。

 

private int[] getXCoordinates(ArrayList seriesData){ 

 int xSpan = (int)GraFixConstants.xSpan; 

           int longestSeries = Utilities.getLongestSeries(seriesData); 

           int numSegments =  

           ((double[])seriesData.get(longestSeries)).length;         

           int sectionWidth =  

           (int)xSpan / numSegments; //want to divide span of xAxis 

         

           int xPositions[] =  

           new int[numSegments]; // will contain X-coordinate of all dots. 

 for(int i=0; i<numSegments; i++){ 

  xPositions[i]=  

  (i+1)*sectionWidth;//dots spaced at distance of sectionWidth    

 } 

 return xPositions; 

} 

 

line 1---> 2048 / 1024 equals 2. 

line 2---> 100 - 0 equals 100.  

line 3---> 100 / 2 equals 50, which is the desired scaled value. 

 

public class MainGraFixView extends ViewPart{ 

 public void createPartControl(Composite parent) { 

   

  //create or get data in an arraylist 

  ArrayList seriesData = dataGenerator(); 



  //instantiate a plotter, and provide data to it. 

  DirectedGraphXYPlotter dgXYGraph = new DirectedGraphXYPlotter(parent); 

  dgXYGraph.setData(seriesData); 

  dgXYGraph.plot(); //ask it to plot    



 } 

 public void setFocus() {  

 } 

} 

 

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.