[vtkusers] QVTKWidget crashes the entire Qt Application on click

[John Eke]

Hello People,

I have a main QWidget, inside which I have added QVTKWidgets.  I was 
wondering what the propper way was to initialize QVTKInteractors so that 
everything works fine. The way I have it setup right now, everything 
loads fine, but once I click on the QVTKWidgets, the entire app crashes 
with a seg fault error.

Heres an example of what I am doing, these are called from within the 
constructor of a subclass of the QVTKWidget:

    //initialize member variables
    m_pImageActor = vtkImageActor::New();
    m_pRenderer = vtkRenderer::New();
   
    //add renderer
    m_pRenderer->SetBackground(0.0, 0.0, 0.0);
    GetRenderWindow()->AddRenderer(m_pRenderer);
    GetRenderWindow()->Render();

    //load an image using ITK
    typedef itk::Image<unsigned char,2> ImageType;
    typedef itk::ImageFileReader<ImageType> ReaderType;
    typedef itk::ImageToVTKImageFilter<ImageType>  ConnectorType;      
    ReaderType::Pointer reader = ReaderType::New();
    ConnectorType::Pointer connector = ConnectorType::New();
   
    //read image and pass it onto the image actor
    reader->SetFileName("temp.png");       
    connector->SetInput (reader->GetOutput());
    m_pImageActor->SetInput(connector->GetOutput());

    //add the image actor to the renderer
    m_pRenderer->AddActor(m_pImageActor);

When I do this, all loads well, but when I click on the QVTKWidget, the 
app crashes with a segmentation fault error. I am assuming maybe I am 
not properly initializing the QVTKInteractor. GetInteractor() gives me 
the QVTKInteractor and SetInteractor() sets it right back. So I am 
assuming the default constructor has already initialized the QVTKInteractor.

Any thoughts/ideas/help will be greatly appreciated!

Thanks
- John