VTK/Examples/Cxx/Graphs/SelectedVerticesAndEdges

#include <vtkSmartPointer.h>
#include <vtkAnnotationLink.h>
#include <vtkRenderedGraphRepresentation.h>
#include <vtkRenderer.h>
#include <vtkHardwareSelector.h>
#include <vtkDoubleArray.h>
#include <vtkSelectionNode.h>
#include <vtkIdTypeArray.h>
#include <vtkSelection.h>
#include <vtkRenderWindow.h>
#include <vtkUnsignedCharArray.h>
#include <vtkObjectFactory.h>
#include <vtkGraphLayoutStrategy.h>
#include <vtkGraphLayoutView.h>
#include <vtkGraphWriter.h>
#include <vtkMutableUndirectedGraph.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSimple2DLayoutStrategy.h>
#include <vtkInteractorStyleRubberBand2D.h>
 
class RubberBandStyle : public vtkInteractorStyleRubberBand2D
{
  public:
    static RubberBandStyle* New();
    vtkTypeMacro(RubberBandStyle, vtkInteractorStyleRubberBand2D);
 
  virtual void OnLeftButtonUp()
  {
    // Forward events
    vtkInteractorStyleRubberBand2D::OnLeftButtonUp();
 
    vtkSelection* selection = this->View->GetRepresentation()->GetAnnotationLink()->GetCurrentSelection();
    vtkSelectionNode* vertices;
    vtkSelectionNode* edges;
    if(selection->GetNode(0)->GetFieldType() == vtkSelectionNode::VERTEX)
      {
      vertices = selection->GetNode(0);
      }
    else if(selection->GetNode(0)->GetFieldType() == vtkSelectionNode::EDGE)
      {
      edges = selection->GetNode(0);
      }
 
    if(selection->GetNode(1)->GetFieldType() == vtkSelectionNode::VERTEX)
      {
      vertices = selection->GetNode(1);
      }
    else if(selection->GetNode(1)->GetFieldType() == vtkSelectionNode::EDGE)
      {
      edges = selection->GetNode(1);
      }
 
    vtkIdTypeArray* vertexList = vtkIdTypeArray::SafeDownCast(vertices->GetSelectionList());
    std::cout << "There are " << vertexList->GetNumberOfTuples() << " vertices selected." << std::endl;
 
    if(vertexList->GetNumberOfTuples() > 0)
      {
      std::cout << "Vertex Ids: ";
      }
    for(vtkIdType i = 0; i < vertexList->GetNumberOfTuples(); i++)
      {
      std::cout << vertexList->GetValue(i) << " ";
      }
 
    std::cout << std::endl;
    vtkIdTypeArray* edgeList = vtkIdTypeArray::SafeDownCast(edges->GetSelectionList());
    std::cout << "There are " << edgeList->GetNumberOfTuples() << " edges selected." << std::endl;
    if(edgeList->GetNumberOfTuples() > 0)
      {
      std::cout << "Edge Ids: ";
      }
 
    for(vtkIdType i = 0; i < edgeList->GetNumberOfTuples(); i++)
      {
      std::cout << edgeList->GetValue(i) << " ";
      }
    std::cout << std::endl;
  }
 
  vtkGraphLayoutView* View;
};
vtkStandardNewMacro(RubberBandStyle);
 
 
int main(int, char *[])
{
  vtkSmartPointer<vtkMutableUndirectedGraph> g =
    vtkSmartPointer<vtkMutableUndirectedGraph>::New();
 
  vtkIdType v1 = g->AddVertex();
  vtkIdType v2 = g->AddVertex();
 
  g->AddEdge(v1, v2);
  g->AddEdge(v1, v2);
 
  vtkSmartPointer<vtkGraphLayoutView> view =
    vtkSmartPointer<vtkGraphLayoutView>::New();
  view->AddRepresentationFromInput(g);
  view->SetLayoutStrategy("Simple 2D");
 
  vtkSmartPointer<RubberBandStyle> style =
    vtkSmartPointer<RubberBandStyle>::New();
  style->View = view;
  view->SetInteractorStyle(style);
 
  view->ResetCamera();
  view->Render();
 
  view->GetInteractor()->Start();
 
  return EXIT_SUCCESS;
}