ScalarMapListener

• To: visad-list@xxxxxxxxxxxxx
• Subject: ScalarMapListener
• From: Donna L Gresh <gresh@xxxxxxxxxx>
• Date: Fri, 21 Feb 2003 13:09:57 -0500

I'm back with another question;
My fundamental need is to combine a "marker" (which might be a line) in a
three-dimensional view. My basic data object is a surface which is mapped
like xy->data, where x->Display.XAxis, y->Display.YAxis, and
data->Display.ZAxis. So I have created a "line object" (which is just two
points: {x, y, zmin} and {x, y, zmax} which marks a particular xy location
with a vertical line. So I have another math type which is {x2,y2,z2} and I
set up scalar maps for x2->Display.XAxis, y2->Display.YAxis, and
z2->Display.ZAxis. I found however that I need to explicitly set the range
for the scalar maps for my marker line to match the range of the surface.
The only problem is one that's been mentioned in the archive, that it takes
some amount of time for the autoscaling to occur. I inserted a short wait,
and that resulted in the right picture, so then I went ahead and created a
new class that implements ScalarMapListener as suggested in the archives.
The constructor for the class gets two scalarmaps: the "source" scalar map
and the "destination" scalar map, so that in the mapChanged method I can do
something like

foo = source.getRange();
destination.setRange(foo[0], foo[1])

The only problem is, the mapChanged method seems to be causing itself to be
called again in an infinite loop. Although I only do
source.addScalarMapListener(myclass); I don't put a listener on the
destination map.

Am I doing something backwards? Is there a simpler way to do what I want?

Thanks for any help
Donna


Donna L. Gresh, Ph.D.
Optimization and Mathematical Software Group
IBM T.J. Watson Research Center
(914) 945-2472
http://www.research.ibm.com/people/g/donnagresh
gresh@xxxxxxxxxx

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    • From: Bill Hibbard
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    • From: Tom Rink