Added RandomGraphSource, SelectedVerticesAndEdges

src/PythonicAPI.md

@@ -312,8 +312,10 @@ This section includes ?vtkUnstructuredGrid?.
 [CreateTree](/PythonicAPI/Graphs/CreateTree) | Create a tree and label the vertices and edges.
 [GraphToPolyData](/PythonicAPI/Graphs/GraphToPolyData) | Convert a graph to a PolyData.
 [LabelVerticesAndEdges](/PythonicAPI/Graphs/LabelVerticesAndEdges) | Label vertices and edges.
+[RandomGraphSource](/PythonicAPI/Graphs/RandomGraphSource) | Create a random graph.
 [SideBySideGraphs](/PythonicAPI/Graphs/SideBySideGraphs) | Display two graphs side by side.
 [ScaleVertices](/PythonicAPI/Graphs/ScaleVertices) | Size/scale vertices based on a data array.
+[SelectedVerticesAndEdges](/PythonicAPI/Graphs/SelectedVerticesAndEdges) |
 [VisualizeDirectedGraph](/PythonicAPI/Graphs/VisualizeDirectedGraph) | Visualize a directed graph.
 
 ### Graph Conversions

src/PythonicAPI/Graphs/RandomGraphSource.py

+#!/usr/bin/env python3
+
+# noinspection PyUnresolvedReferences
+import vtkmodules.vtkInteractionStyle
+# noinspection PyUnresolvedReferences
+import vtkmodules.vtkRenderingOpenGL2
+from vtkmodules.vtkCommonColor import vtkNamedColors
+from vtkmodules.vtkInfovisCore import vtkRandomGraphSource
+# noinspection PyUnresolvedReferences
+from vtkmodules.vtkInfovisLayout import vtkForceDirectedLayoutStrategy
+from vtkmodules.vtkViewsInfovis import vtkGraphLayoutView
+
+
+def main():
+    colors = vtkNamedColors()
+
+    # seed=123 ensures repeatable results for testing. Remove this off for real use.
+    random_graph_source = vtkRandomGraphSource(number_of_vertices=5, number_of_edges=4, seed=123)
+    random_graph_source.update()
+
+    # force_directed = vtkForceDirectedLayoutStrategy()
+
+    graph_layout_view = vtkGraphLayoutView()
+    graph_layout_view.AddRepresentationFromInput(random_graph_source.GetOutput())
+    # If we create a layout object directly, just set the pointer through this method.
+    # graph_layout_view.SetLayoutStrategy(force_directed)
+    graph_layout_view.SetLayoutStrategyToForceDirected()
+    graph_layout_view.renderer.background = colors.GetColor3d('Navy')
+    graph_layout_view.renderer.background2 = colors.GetColor3d('MidnightBlue')
+    graph_layout_view.render_window.window_name = 'RandomGraphSource'
+    graph_layout_view.Render()
+    graph_layout_view.ResetCamera()
+    graph_layout_view.interactor.Start()
+
+
+if __name__ == '__main__':
+    main()

src/PythonicAPI/Graphs/SelectedVerticesAndEdges.md

+### Description
+
+* Contributed by Eric Monson

src/PythonicAPI/Graphs/SelectedVerticesAndEdges.py

+#!/usr/bin/env python3
+
+# noinspection PyUnresolvedReferences
+import vtkmodules.vtkInteractionStyle
+# noinspection PyUnresolvedReferences
+import vtkmodules.vtkRenderingOpenGL2
+from vtkmodules.vtkInfovisCore import vtkRandomGraphSource
+from vtkmodules.vtkViewsInfovis import vtkGraphLayoutView
+
+
+def selection_callback(caller, event):
+    # Use the shift key to select both nodes and edges.
+    # The nodes can either vertices or edges.
+    sel = caller.current_selection
+    node0 = sel.GetNode(0)
+    node0_field_type = node0.field_type
+    sel_list0 = caller.current_selection.GetNode(0).selection_list
+    node1 = sel.GetNode(1)
+    node1_field_type = node1.field_type
+    sel_list1 = caller.current_selection.GetNode(1).selection_list
+
+    if sel_list0.number_of_tuples > 0:
+        # print('node0:')
+        print_field_type(node0_field_type)
+        for ii in range(sel_list0.number_of_tuples):
+            print(' ', sel_list0.GetValue(ii))
+
+    if sel_list1.number_of_tuples > 0:
+        # print('node1:')
+        print_field_type(node1_field_type)
+        for ii in range(sel_list1.number_of_tuples):
+            print(' ', sel_list1.GetValue(ii))
+
+        print('- - -')
+
+
+def print_field_type(field_type):
+    if field_type == 3:
+        print('Vertex Id(s) Selected:')
+    elif field_type == 4:
+        print('Edge Id(s) Selected:')
+    else:
+        print('Unknown type:')
+
+
+def main():
+    source = vtkRandomGraphSource()
+    source.Update()
+
+    view = vtkGraphLayoutView()
+    view.AddRepresentationFromInputConnection(source.GetOutputPort())
+
+    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', selection_callback)
+
+    view.GetRenderWindow().SetSize(600, 600)
+    view.ResetCamera()
+    view.Render()
+    view.GetInteractor().Start()
+
+
+if __name__ == '__main__':
+    main()