UserEvent

VTKExamples/Cxx/Interaction/UserEvent

Code

UserEvent.cxx

#include <vtkSphereSource.h>
#include <vtkCallbackCommand.h>
#include <vtkCommand.h>
#include <vtkPolyData.h>
#include <vtkSmartPointer.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>

#include "vtkTestFilter.h"

static void CallbackFunction(vtkObject* caller,
                long unsigned int eventId,
                void* clientData,
                void* callData );

int main(int, char *[])
{
  // Create a renderer, render window, and interactor
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  vtkSmartPointer<vtkTestFilter> filter =
    vtkSmartPointer<vtkTestFilter>::New();

  vtkSmartPointer<vtkCallbackCommand> callback =
    vtkSmartPointer<vtkCallbackCommand>::New();
  callback->SetCallback(CallbackFunction );
  filter->AddObserver(filter->RefreshEvent, callback);

  filter->Update();

  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

void CallbackFunction(vtkObject* caller,
                long unsigned int eventId,
                void* clientData, void* callData )
{
  std::cout << "CallbackFunction called." << std::endl;
}

vtkTestFilter.h

#ifndef __vtkTestFilter_h
#define __vtkTestFilter_h

#include "vtkPolyDataAlgorithm.h"

class vtkTestFilter : public vtkPolyDataAlgorithm
{
public:
  vtkTypeMacro(vtkTestFilter,vtkPolyDataAlgorithm);
  static vtkTestFilter *New();

  int RefreshEvent;

protected:
  vtkTestFilter();

  int RequestData(vtkInformation *, vtkInformationVector **, vtkInformationVector *);

private:
  vtkTestFilter(const vtkTestFilter&);  // Not implemented.
  void operator=(const vtkTestFilter&);  // Not implemented.

};

#endif

#include "vtkObjectFactory.h"
#include "vtkCommand.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkInformationVector.h"
#include "vtkInformation.h"
#include "vtkDataObject.h"
#include "vtkSmartPointer.h"
#include "vtkAppendPolyData.h"
#include "vtkSphereSource.h"

vtkStandardNewMacro(vtkTestFilter);

vtkTestFilter::vtkTestFilter()
{
  this->SetNumberOfInputPorts(0);

  this->RefreshEvent = vtkCommand::UserEvent + 1;

}

int vtkTestFilter::RequestData(vtkInformation *vtkNotUsed(request),
                                             vtkInformationVector **inputVector,
                                             vtkInformationVector *outputVector)
{
  // Get the info object
//  vtkInformation *outInfo = outputVector->GetInformationObject(0);

//  vtkPolyData *output = vtkPolyData::SafeDownCast(
//      outInfo->Get(vtkDataObject::DATA_OBJECT()));
  this->InvokeEvent(this->RefreshEvent, NULL);

  return 1;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(UserEvent)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

add_executable(UserEvent MACOSX_BUNDLE UserEvent.cxx )

target_link_libraries(UserEvent ${VTK_LIBRARIES})

Download and Build UserEvent

Click here to download UserEvent and its CMakeLists.txt file. Once the tarball UserEvent.tar has been downloaded and extracted,

cd UserEvent/build 

If VTK is installed:

cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

make

and run it:

./UserEvent

WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.