From: Ian Turton <i.turton@ge...> - 2002-05-23 14:24:09
At 14:31 23/05/02, Ostrowski, Steven wrote:
>Hello GT2 developers,
> Please keep in mind a wide range of applications of GT2 during the
>design and implementation. GT is definitely more geared towards displaying
>existing data rather than editing maps and saving them, but this may
>definitely be a big use. For example, an application that receives lightning
>strikes as they come in, then wants to use GT to draw a circle (or better
>yet, a custom icon) at the location from the geographic map displayed. This
>drawing should be able to correlate with the real map coordinates, be able
>to be drawn in a separate layer that can be saved separate from the existing
>map shapefile, etc. This requires an application to be able to command the
>map rather than an application having to become a "client" of the map as the
>Tool interface requires now in GT1.
what you want to do is very easy in gt1, create a circleLayer and
place it in a theme and view it. Write a method called lightningHit(x,y);
It should create a GeoCircle using the x and y passed in set an appropriate
radius and then add that GeoCircle to the circle layer. The theme and the
viewer will take care of updating the display for you.
If you want a custom mark then you need to investigate marker layer and how
to write a mark,
Alternatively you could generate a density surface of lightning strikes by
adding your GeoCircles to a circleRaster layer. GeoTools provides you with
an almost infinite range of ways to display data as it is generated -
especially for circles that was the reason it was written in the first place.
> I think that making such editing almost as simple as the displaying
>will make GT more widely used and a much more powerful tool.
Editing is harder - that's mostly because its not something most users want
to do, partly because James and I both have "proper" GIS available to use
for editing maps.
PS I haven't had a chance to look at your tool code since your server was
down this morning (my time).
Ian Turton, Centre for Computational Geography, School of Geography,
University of Leeds, Leeds, LS2 9JT. ***0113 3433392 - New Phone No***