[vtk-developers] My vtk class override not being used when an override already exists.

[Marcus D. Hanwell]

On Mon, Mar 4, 2013 at 9:02 AM, Berk Geveci <berk.geveci at kitware.com> wrote:
> This looks good. Do you have a few spare cycles to investigate what it
> would take to do this in VTK? The broader question still remains
> though. Should this be enabled for every single class in VTK? My gut
> feeling says that we would exclude Common at the least. For one, I am
> not very comfortable with people overriding vtkDataArray for example.
> Also, it is still a potential performance problem even when doing
> something faster like hashing. What do you guys think?
>
Since we made the change to disable object factories by default, and
only enable them for a select few classes we have had very few people
complain, it seemed like a sledge hammer of a solution for something
that is not universally required. Most other toolkits/libraries I have
seen will use factories in one or two places where they make sense,
rather than for every class.

We still retain the capability of changing an option which lets you
recompile the toolkit with object factories for every class where
required - it is off by default. I think whatever we decide it would
be nice to add some capability for overriding an already overridden
class for the case where a module wants to override one class already
overridden by a larger module such as vtkRenderingOpenGL, but as you
say the ideal is that those changes migrate upstream into VTK.

Marcus