Re: Listening for key events

Hi Cristy,
> My question is, how can I intercept tab/shift-tab key presses
> when the graph has focus so I can in-turn move the green blob?
> I tried adding a KeyListener without any luck.  I also checked
> out the VisAD examples and did not see any that react to key
> presses.
Yes, we don't have any examples that capture keyboard events
for VisAD displays.  Also, you cannot use a KeyListener
directly with Java3D, since it grabs all the KeyEvents itself.
But it will give them back through a Behavior in the Java3D
scene graph.  Here's how to do it.  Define a new class
KeyBehaviorJ3D (or whatever name you like) that is similar
to visad.java3d.MouseBehaviorJ3D, except that:

1. It extends Behavior but does not implement the MouseEvent 
2. It does not construct a MouseHelper or implement the
   getMouseHelper() method.
3. It defines a different list of conditions in its constructor
   in 'wakeup', maybe just
   new WakeupOnAWTEvent(KeyEvent.KEY_PRESSED)
4. In its processStimulus method, it does not pass
   AWTEvents to MouseHelper.processEvent(), but instead
   moves your green blob or does whatever else you want.
Then in your application, after you have constructed your
DisplayImplJ3D, do the following:
  DisplayImplJ3D display = ...;
  DisplayRendererJ3D display_renderer
    (DisplayRendererJ3D) display.getDisplayRenderer();
  TransformGroup trans = display_renderer.getTrans();
  KeyBehaviorJ3D key = new KeyBehaviorJ3D(display_renderer);
  BoundingSphere bounds
    new BoundingSphere(new Point3d(0.0,0.0,0.0), 2000000.0);
I have never used KeyEvents, so may have made some error here,
but I think this is the general idea.  Please let me know if
you have problems.

Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738

>From owner-visad@xxxxxxxxxxxxxxxx Wed 8  2004 Dec 10:52:59
Message-ID: <1102503179.41b6dd0b4f4b6@xxxxxxxxxxxxxxxxxxx>
Date: Wed,  8 Dec 2004 10:52:59 +0000
From: Adityarajsingh Santokhee <ads@xxxxxxxxxxxxxxxxxxxx>
In-Reply-To: <41B60B12.4040500@xxxxxxxx>
To: visad-list@xxxxxxxxxxxxx
Subject: Re: Example of 2D surface animation
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Thanks Curtis,

Your program has solved my problem.



Quoting Curtis Rueden <ctrueden@xxxxxxxx>:

> Hi Adit,
> I have posted an example of surface animation as Bill described online at:
> Hopefully it will be of some help.
> -Curtis
> Adityarajsingh Santokhee wrote:
> >>You can see temps moving on a constant surface if you use
> >>the same values for "z" in all time steps. You can reuse
> >>the same float[] array of "z" values in the range float[][]
> >>for each time step.
> >>    
> >>
> >
> >
> >I have in fact kept the "z" values constant. What I wanted to say is that
> the
> >lat-lon surface is actually moving along the longitude axis with each
> >timestep.
> >
> >Maybe I need to change the way I am defining my Math Types/scalar Maps.
> >
> >Cheers,
> >Adit
> >  
> >

 Adityarajsingh Santokhee         Tel: +44 118 378 5213 (direct line)
 eScience Data Manager            Tel: +44 118 378 8741 (ESSC)
 Reading e-Science Centre         Fax: +44 118 378 6413
 ESSC                             Email: ads@xxxxxxxxxxxxxxxxxxxx
 University of Reading
 3 Earley Gate
 Reading RG6 6AL, UK


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