from vtk import *

source = vtkRandomGraphSource()
source.DirectedOff()
source.SetNumberOfVertices(100)
source.SetEdgeProbability(0.1)
source.SetUseEdgeProbability(True)
source.AllowParallelEdgesOn()
source.AllowSelfLoopsOn()
source.SetStartWithTree(True)

# Connect to the centrality filter.
centrality = vtkBoostBrandesCentrality ()
centrality.SetInputConnection(source.GetOutputPort())

# Find the minimal spanning tree
mstTreeSelection = vtkBoostKruskalMinimumSpanningTree()
mstTreeSelection.SetInputConnection(centrality.GetOutputPort())
mstTreeSelection.SetEdgeWeightArrayName("centrality")
mstTreeSelection.NegateEdgeWeightsOn()
mstTreeSelection.Update()

# Take selection and extract a graph
extract_graph = vtkExtractSelectedGraph()
extract_graph.AddInputConnection(centrality.GetOutputPort())
extract_graph.SetSelectionConnection(mstTreeSelection.GetOutputPort())

# Extract a tree from the graph
extract_tree = vtkBoostBreadthFirstSearchTree()
extract_tree.AddInputConnection(extract_graph.GetOutputPort())

# Create a graph layout view
view = vtkGraphLayoutView()
view.AddRepresentationFromInputConnection(centrality.GetOutputPort())
view.SetVertexLabelArrayName("centrality")
view.SetVertexLabelVisibility(True)
view.SetVertexColorArrayName("centrality")
view.SetColorVertices(True)
view.SetEdgeColorArrayName("centrality")
view.SetColorEdges(True)
view.SetLayoutStrategyToSimple2D()

# Setup a couple layout strategies so we can switch
# them out for comparison
treeStrat = vtkTreeLayoutStrategy();
treeStrat.RadialOn()
treeStrat.SetAngle(120)
treeStrat.SetLogSpacingValue(1)
forceStrat = vtkSimple2DLayoutStrategy()
forceStrat.SetEdgeWeightField("centrality")

# Create an HGV
view2 = vtkHierarchicalGraphView()
view2.SetHierarchyFromInputConnection(extract_tree.GetOutputPort())
view2.SetGraphFromInputConnection(centrality.GetOutputPort())
view2.SetVertexColorArrayName("centrality")
view2.SetColorVertices(True)
view2.SetVertexLabelArrayName("centrality")
view2.SetVertexLabelVisibility(True)
view2.SetEdgeColorArrayName("centrality")
view2.SetColorEdges(True)
view2.SetBundlingStrength(.75)
view2.SetLayoutStrategy(forceStrat)
#view2.SetLayoutStrategy(treeStrat)

# Make sure all views are using a pedigree id selection
view.GetRepresentation(0).SetSelectionType(2)
view2.GetRepresentation(0).SetSelectionType(2)

# Create a selection link and set both view to use it
annotationLink = vtkAnnotationLink()
view.GetRepresentation(0).SetAnnotationLink(annotationLink)
view2.GetRepresentation(0).SetAnnotationLink(annotationLink)
annotationLink.SetCurrentSelection(mstTreeSelection.GetOutput())

# Make updater to update views on selection change
updater = vtkViewUpdater()
updater.AddView(view)
updater.AddView(view2)

# Set the theme on the view
theme = vtkViewTheme.CreateMellowTheme()
theme.SetLineWidth(4)
theme.SetPointSize(8)
theme.SetSelectedCellColor(1,0,1)
theme.SetSelectedPointColor(1,0,1)
view.ApplyViewTheme(theme)
theme.SetLineWidth(1)
view2.ApplyViewTheme(theme)
theme.FastDelete()

view.GetRenderWindow().SetSize(600, 600)
view.ResetCamera()
view.Render()

view2.GetRenderWindow().SetSize(600, 600)
view2.ResetCamera()
view2.Render()

view.GetInteractor().Start()