Source Code for Package visgraph.layouts

 1  ''' 
 2  A package for each of the different layout managers. 
 3  ''' 
 4   
 5   
 6  # Some helper utils... 
 7 -def exit_pos(ninfo): 
 8      x,y = ninfo.get('position') 
 9      xsize, ysize = ninfo.get('size', (0,0)) 
10      return (x + xsize/2, y + ysize) 
11   
12 -def entry_pos(ninfo): 
13      x,y = ninfo.get('position') 
14      xsize, ysize = ninfo.get('size', (0,0)) 
15      return (x + xsize/2, y) 
16   
17 -def center_pos(ninfo): 
18      x,y = ninfo.get('position') 
19      xsize, ysize = ninfo.get('size', (0,0)) 
20      return (x + (xsize/2), y + (ysize/2)) 
21   
22 -class GraphLayout: 
23   
24 -    def __init__(self, graph): 
25          self.graph = graph 
26   
27 -    def layoutGraph(self): 
28          ''' 
29          Layout the graph nodes and edges 
30          ''' 
31          raise Exception('%s must implement layoutGraph()!' % self.__class__.__name__) 
32   
33 -    def getLayoutSize(self): 
34          raise Exception('%s must implement getLayoutSize()!' % self.__class__.__name__) 
35   
36 -    def renderGraph(self, rend): 
37          ''' 
38          Render the graph to the given renderer. 
39          ''' 
40          rend.setNodeSizes(self.graph) 
41          self.layoutGraph() 
42   
43          width, height = self.getLayoutSize() 
44          rend.beginRender(width, height) 
45   
46          # Render each of the nodes (except ghost nodes...) 
47          for nid,ninfo in self.graph.getNodes(): 
48              if ninfo.get('ghost'): 
49                  continue 
50              xpos, ypos = ninfo.get('position') 
51              rend.renderNode(nid, ninfo, xpos, ypos) 
52   
53          # Render the edges 
54          for eid, fromid, toid, einfo in self.graph.getEdges(): 
55              points = einfo.get('edge_points') 
56              if points != None: 
57                  rend.renderEdge(eid, einfo, points) 
58   
59          rend.endRender() 
60