[vtk-developers] abstract/concrete etc

[David Gobbi]

On Sat, 24 Feb 2001, John Biddiscombe wrote:

> I asked some time ago if anyone could explain why certain classes are 
> declared as concrete
> vtkObject, vtkProcessObject, vtkImageSource etc etc
> when they aren't supposed to be.

I know what you mean by 'aren't supposed to be,' but I'm not sure if I
agree with you.  These classes are concrete (in the C++ sense) so why
not declare them as such in the makefiles?  Some people might find a
use for them.

> some, such as vtkImageMapper are overridden in the object factories to 
> create the correct type so are allowed to be concrete, but many are not. 
> I'd like to change some to abstract in the makefile.in files
> a) does anyone object
> b) will newer parsing code invalidate it all anyway? (I suspect not, 
> because it still won't know that vtkProcessObect is abstract...)

It would break some of my code, because I use plain-vanilla vtkObject
instances as timestamps (because vtkTimeStamp itself isn't wrapped).
Why do you want to make these changes?

 - David

--
  David Gobbi, MSc                    dgobbi at irus.rri.on.ca
  Advanced Imaging Research Group
  Robarts Research Institute, University of Western Ontario