SelectedVerticesAndEdges
VTKExamples/Python/Graphs/SelectedVerticesAndEdges
Description
*Contributed by Eric Monson
Code
SelectedVerticesAndEdges.py
#!/usr/bin/env python
from __future__ import print_function
import vtk
source = vtk.vtkRandomGraphSource()
source.Update()
view = vtk.vtkGraphLayoutView()
view.AddRepresentationFromInputConnection(source.GetOutputPort())
def selectionCallback(caller, event):
# In C++ there is some extra data passed to the callback, but in Python
# the callback data is lost...
# There should be two selection nodes, but which one is vertices and which
# is edges does not seem to be guaranteed...
sel = caller.GetCurrentSelection()
node0 = sel.GetNode(0)
node0_field_type = node0.GetFieldType()
sel_list0 = caller.GetCurrentSelection().GetNode(0).GetSelectionList()
node1 = sel.GetNode(1)
node1_field_type = node1.GetFieldType()
sel_list1 = caller.GetCurrentSelection().GetNode(1).GetSelectionList()
if (sel_list0.GetNumberOfTuples() > 0):
printFieldType(node0_field_type)
for ii in range(sel_list0.GetNumberOfTuples()):
print("\t", sel_list0.GetValue(ii))
if (sel_list1.GetNumberOfTuples() > 0):
printFieldType(node1_field_type)
for ii in range(sel_list1.GetNumberOfTuples()):
print("\t", sel_list1.GetValue(ii))
print("- - -")
def printFieldType(field_type):
if field_type == 3:
print("Vertices Selected:")
elif field_type == 4:
print("Edges Selected:")
else:
print("Unknown type:")
rep = view.GetRepresentation(0)
# The vtkRenderedGraphRepresentation should already have a vtkAnnotationLink,
# so we just want to grab it and add an observer with our callback function
# attached
link = rep.GetAnnotationLink()
link.AddObserver("AnnotationChangedEvent", selectionCallback)
view.GetRenderWindow().SetSize(600, 600)
view.ResetCamera()
view.Render()
view.GetInteractor().Start()