def showShortestPath(self, startPoint, endPoint):
# taken from Qgis Py Cookbook
#startPoint = self.ptList[0][0].asPoint()
#endPoint = self.ptList[1][0].asPoint()
tiedPoints = self.director.makeGraph(self.builder,
[startPoint, endPoint])
tStart, tStop = tiedPoints
graph = self.builder.graph()
idxStart = graph.findVertex(tStart)
tree = QgsGraphAnalyzer.shortestTree(graph, idxStart, 0)
idxStart = tree.findVertex(tStart)
idxEnd = tree.findVertex(tStop)
if idxEnd == -1:
raise Exception('No route!')
# Add last point
route = [tree.vertex(idxEnd).point()]
# Iterate the graph
while idxEnd != idxStart:
edgeIds = tree.vertex(idxEnd).incomingEdges()
if len(edgeIds) == 0:
break
edge = tree.edge(edgeIds[0])
route.insert(0, tree.vertex(edge.fromVertex()).point())
idxEnd = edge.fromVertex()
# This may require coordinate transformation if project's CRS
# is different than layer's CRS
for p in route:
self.rbShortPath.addPoint(p)
return route
def calcShortestTree(self, startpoint_id, criterion):
tree = QgsGraphAnalyzer.shortestTree(self.network, startpoint_id,
criterion)
return tree
