[Chameleon] Using shapes drawin using ROI tools

[Mike Leahy]

Hello list,

I'm currently working on a tool that allows users to define study areas
by selecting features interactively on a map.  We've previously
accomplished with some success using the Rosa applet, but we'd like to
make the change to Chameleon - browser compatibility and flexibility of
design being two of the stronger motivators for doing so.  However, the
Chameleon query tool still only allows point selections.  Furthermore,
since the ability to select by rectangle, circle or polygon is somewhat
important for our application, I'd like to know how difficult it might
be to use the existing functionality in the ROI group of widgets. 
Basically, what I'd like to know is how I can get the shape(s) drawn
with the ROI widgets so I can perform queries against a PostGIS table. 
We'll likely be adding functionality for other options (e.g., features
within a given distance from the ROI, or from selected features), so I'm
thinking that getting the ROI shapes, performing the appropriate
queries, then adding classes or layers to the map in Chameleon is likely
our best option.

I can probably get this figured out on my own after a fair bit of
tinkering...but I'm hoping that some of the participants in this list
can offer a some tips that would give me a head start.  Or perhaps there
are some other widgets, or some ways of using the ROI widgets that can
accomplish something like what we're looking to do.

Thanks in advance for any advice.
Mike