[vtk-developers] Widgets within Widgets & vtkHandleWidget

[John Biddiscombe]

> vtkButtonWidget. I was thinking that a class like 
> vtkHandleWidget could be 
> created to be used by all widgets to create handles. This 
> thing could have 

Yes. Perfect.

> this stuff. Thoughts? My major concern is that if adopted, it 
> would affect 
> the API of the current widget set.

OK, but the widget development is early enough on in it's development
for us to do some breaking, because those using it are a managable
subset of everyone I guess.

However, the ideal solution from my point of view is simply...
Create a widget Directory parallel to imaging/filtering/graphics/etc,
start creating a new set of widgets from the base up which form a new
API. Deprecate all the widgets in Hybrid, but leave them there until 5.0
and start moving the functionality into the a new architecture/framework
based around the new classes.

There seem to be distinct of families of widgets...

Geometric Widgets : BoxWidget/PointWidget/LineWidget/PlaneWidget etc etc
  these have fairly simple and similar interfaces and allow the user to
control pipelines which use the geometry of the wdigets to affect their
data/visualization

ControllerWidgets : like the proposed transferfunction widget and
ImageTracerWidget, which in their own right form a complete
"environment", they can have inputs, and outputs, but their purpose is
less direct than the geometric ones and they don't need to export
"geometries" in the same way. They can export anything like lookuptables
piecewisefunctions transforms if need be, etc.

I convinced myself that there were other categories of widget, but I've
gone dry and can't recall what I had in mind

Comments please...

JB