Java/Swarm questions

[Charles Staelin]

After a long hiatus, I am again learning Java and Swarm by working through
the Simplebug Swarm tutorial, translating the Objective C programs into
Java.  I'm almost done and, when I have finished, I'll take a few hours to
document the tutorial for Java and post it.  At the moment I have two
questions that perhaps someone could answer for me.

1. The ObjectiveC Simplebug programs send a "doTkEvents" message to the
control panel in order to update the display and check for a control panel
button push at each step.  The jheatbugs programs send the same message to
the ActionClass to do the same thing.  Indeed, if the message is sent to the
control panel, the raster display is never updated.  Is the ActionClass a
superclass for the control panel in the java version of things?  Or is the
Simplebug code simply out of date?  When would you send a doTkEvents message
to the control panel alone?

2. What is the best way to shut down a Swarm application if one detects an
unrecoverable error in the code?  Is there a graceful way, or needn't one
worry about grace in this event?

3. I find that my ObserverSwarms work fine unless I click on the display
raster window during a simulation.  If I do that, the whole machine hangs.
(I'm in Windows with Swarm 2.1 and the latest fixes.)  Is the raster window
supposed to respond in some way to being "selected"?

Thanks for any advice.

Charles

--------------------------------------------------------------------------
Charles P. Staelin                              address@hidden
Department of Economics
Smith College                                    (413) 585-3621
Northampton, MA 01063                  (413) 585-3393 (FAX)


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