[Insight-developers] Modes versus Objects

[David Cole]

What is the weakness? How can it be fixed?

What could have prevented this?


On Thu, Jun 2, 2011 at 11:49 AM, Bill Lorensen <bill.lorensen at gmail.com>wrote:

> The dashboard should not get this red in the first place. It shows a
> breakdown/weakness in our process.
>
> With our tools there is no way it should have gotten this red.
>
>
>
> On Thu, Jun 2, 2011 at 11:46 AM, Luis Ibanez <luis.ibanez at kitware.com>
> wrote:
> > Bill,
> >
> > Yeap,
> >
> > We need more of these guiding principles,
> >
> > and
> > we need to capture them somewhere in the Wiki,
> > so they are available for quick reference when
> > we are making code changes.
> >
> > Something along the lines of what we have in:
> >
> > http://www.itk.org/Wiki/ITK_Coding_Style_Guide
> > http://www.itk.org/Wiki/ITK_Code_Review_Check_List
> >
> > Otherwise,
> > it is easy to settle for the quickest solution
> > that let the Dashboard go back to green.
> >
> > Here is a first cut at that new Wiki
> > page on Design Principles:
> >
> > http://www.itk.org/Wiki/ITK_Design_Principles
> >
> >
> > and it is now linked from:
> > http://www.itk.org/Wiki/ITK_Policies_and_Procedures
> >
> >
> >     Luis
> >
> >
> > ------------------
> > On Thu, Jun 2, 2011 at 11:32 AM, Bill Lorensen <bill.lorensen at gmail.com>
> wrote:
> >> Folks,
> >>
> >> This discussion is motivated by recent activity...
> >>
> >> Back in the early days of OO programming, I recall having discussions
> >> about the use of modes versus objects. When I taught OO courses I
> >> always discouraged modes if they changed the "identity" of the object.
> >>
> >> Should a mode be used to change the behaviour of an object or should a
> >> new object be created?
> >>
> >> A case where a mode is better than an object:
> >> Controlling the visibility of an actor in VTK:
> >>  1) Mode: vtkActor VisibilityOn/Off
> >> or
> >>  2) Object: two classes vtkActor and vtkVisibleActor
> >>
> >>  1) is the appropriate solution since, at run time, an application
> >> may want to change the visibility of an actor.
> >>
> >> A case where an object may be better than a mode:
> >>  1) Mode: itkShiftScaleImageFilter
> >> SetOperationOrderToShiftScale()/SetOperationOrderToScaleShift()
> >> or
> >>  2) Object: two classes itkShiftScaleImageFilter and
> itkScaleShiftImageFilter
> >>
> >>  A VTK approach versus an ITK approach
> >>  1) mode: vtkImageMathematics 21 different modes
> (ADD,SUBTRACT,MULTIPLY,...)
> >>  2) object: itkAddImageFilter, itkSubtractImageFilter,
> >> itkMultipleImageFilter...
> >>
> >> It is not always obvious as to the best choice. But, I think the
> >> question should be asked anytimne we introduce a new "mode".
> >>
> >> Bill
> >> _______________________________________________
> >> Powered by www.kitware.com
> >>
> >> Visit other Kitware open-source projects at
> >> http://www.kitware.com/opensource/opensource.html
> >>
> >> Kitware offers ITK Training Courses, for more information visit:
> >> http://kitware.com/products/protraining.html
> >>
> >> Please keep messages on-topic and check the ITK FAQ at:
> >> http://www.itk.org/Wiki/ITK_FAQ
> >>
> >> Follow this link to subscribe/unsubscribe:
> >> http://www.itk.org/mailman/listinfo/insight-developers
> >>
> >
> _______________________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Kitware offers ITK Training Courses, for more information visit:
> http://kitware.com/products/protraining.html
>
> Please keep messages on-topic and check the ITK FAQ at:
> http://www.itk.org/Wiki/ITK_FAQ
>
> Follow this link to subscribe/unsubscribe:
> http://www.itk.org/mailman/listinfo/insight-developers
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.itk.org/mailman/private/insight-developers/attachments/20110602/e0665ba9/attachment.htm>