[vtkusers] Question for C++ Gurus!

[Michael Knopke]

If you just want to have access to only one object of that class you can
give a pointer to this object to your callback

vtkCallbackCommand * keypressCB = vtkCallbackCommand::New();
 keypressCB->SetCallback(&CSdiogl2View::myKeyPressCallback);

style = vtkInteractorStyleTrackballActor::New();
 style->AddObserver(vtkCommand::LeftButtonReleaseEvent,keypressCB);
 style->SetClientData(myObject);
 iren->SetInteractorStyle(style);

void CSdiogl2View::myKeyPressCallback(vtkObject* obj, unsigned long eventId, void * clientdata, void * calldata)
{

  MyClass* self = reinterpret_cast<MyClass *>( clientdata );
  self->DoSomething;

}

but maybe I misunderstand the context...

You can also subclass vtkCommand.

Michael