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Re: [Fwd: AnimationControl - turning animation string on/off.]
Bill-
Bill Hibbard wrote:
> Thanks. Nice to see that you were able to accomplish the
> same thing by an extension of DefaultDisplayRendererJ3D.
Seems like overkill to have to do this, but it worked. And
I will probably use this in the future instead of the
AnimationControl changes for the reasons I state below.
> Since I've already committed Jim's code, since it makes
> this functionality accessible without any class extenson,
> and since AnimationControl is a natural and more specific
> place for this logic, I'll stick with that.
Actually, I think DisplayRenderer is the more appropriate place
for this since it is something that the DisplayRenderer controls
just like the VisAD Box and the cursor string and it's the
DisplayRenderer subclasses who actually have to render the string,
not the AnimationControl. And my suggested changes to DisplayRenderer
(e.g., setAnimationStringVisible) do not need any class extensions.
Every display has a DisplayRenderer which controls this globally
and you can easily toggle it on and off at the Display level.
If you call clearMaps() on the display and then add back in
ScalarMaps, including one to Animation, then the enabling/disabling
of the animation string is not persisted/carried along. You have
to manually go back and reset it to what it was before. However,
if you had methods in the DisplayRenderer to enable/disable the
drawing of the animation string, when the ScalarMaps are removed/added,
it would just keep the same state as before. Just one less
housekeeping item to keep track of and it is more logical to
have the DisplayRenderer which draws the string by calling
getAnimationString() decide whether or not to draw it. And
it only requires modifying one class (well two if you want
to add it into RendererControl).
When VisAD was being developed, the model was that you
set up your entire display, added in all ScalarMaps, added
your data, set all parameters on controls and never changed
a thing. That's how most of the examples and the collaborative
stuff works. In practice, VisAD has developed beyond that
model, where ScalarMaps and controls are added/removed by
user interactions in UI's. Applications like the IDV take
advantage of this evolution. As VisAD continues to develop,
this new model should be used when deciding where to add
enhancements.
Since the code you checked in is only in the untested stuff,
it would be easy enough to back out of (that's what CVS is
for). Jim (and other renderer-list people), what do you think of
this approach?
> Jim, new variables in subclasses of Control should be
> incorporated in the equals() and syncControl() methods.
> I've done this for showAnimationString.
Don
*************************************************************
Don Murray UCAR Unidata Program
dmurray@unidata.ucar.edu P.O. Box 3000
(303) 497-8628 Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
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