[GRASS5] Need help debugging problem with thematic mapping script

[Michael Barton]

I¹ve run into a small but annoying bug that shows up when implementing the
thematic mapping script in the GIS Manager.  I¹ve tried innumerable ways to
fix this‹trying tweaks in d.m.tcl, d.vect.thematic, and thematic.tcl--but it
still occurs. Here is the strange behavior.

If you create a thematic map layer in the GIS Manager, and select the option
to create a graphic legend, the GIS Manager will hang unless the monitor for
the legend display is already running. If the monitor for the legend is NOT
running, d.vect.thematic will start the monitor and draw the legend.
However, all processing will then stop and the GIS Manager will hang. If you
close this monitor, processing will continue and the GIS Manager will
respond. If the monitor chosen for the legend IS running, processing will
proceed normally.

As far as I can tell, this behavior is the same regardless of how the script
is actually run in the GIS Manger (i.e., run using the TclTk open command,
run in a terminal, run using exec, etc.).

Here is what is actually happening in the script. If you create a thematic
map layer in the GIS Manager, and select the option to create a graphic
legend, the d.vect.thematic script will use an if clause to check to see if
the monitor selected for the legend is running. If the monitor chosen for
the legend is NOT running, the script will start the monitor (d.mon start=).
If it IS running, the script will select that monitor (d.mon select=). Then
the script will continue to erase the monitor (d.erase), draw the legend
using d.graph (d.graph input=), and reselect the original display monitor
used for thematic map display (d.mon select=).

The only difference between the situation of the chosen legend monitor being
running or not is that the script will start the monitor if not running and
select it if running. Then the same commands are run in either case. The
script is doing all this correctly‹even running the commands and proceeding
the the cleanup procedure that ends the script. BUT it hangs the GIS Manager
if it has to start the monitor; it does not hang the GIS Manager if it has
to select the monitor.

I am completely baffled. Hopefully someone else can figure this out. Thanks.

Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton


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