Re: [udig-devel] AVL (Automatic Vehicle Location)

[jeichar@xxxxxxxxxxxxxxx]

Quoting Ahmed Al-Obaidy <ahmad@xxxxxxxxxxxxxx>:

> Thank you Jesse and Jody for the response..
> 
> Jesse: Cloud you please give me more details about
> your idea to solve this problem.
> Especially about the tool extension point and how I
> can save it in centralized server that many clients
> could access simultaneously.
> 
> Thank you very much again.
> 
> Ahmad
> 

My understanding of your problem is a little shaky right now.  So I can't give
you a perfect design.  I also don't know where you stand in your understanding
of UDIG so I'll outline some of the main parts of the UDIG system and maybe you
can get an idea of how to approach the problem.  

1. Tools are used to interact with the user, not too much of a surprise I'm
sure.  There is a framework associated with tools and the extension point to
make developing tools easier.  A tool receives mouse events, keyboard events and
using those event can affect the current map.  I guess I should note that tools
only apply if there is an open map.  

2. A map has layers.  Each layer (usually) corresponds to a IGeoResource that
exists in the catalog.  An important point to note is that nothing says a layer
MUST be rendered, but typically they are.  A Map has other bits as well but I
don't think they apply to our discussion right now.

3. GeoResources are part of the catalog and are handles to "real" data.  A
georesource might be a handle to a layer in a WMS or a feature type in a WFS.

4. Services contain GeoResources and are handles to "real" services (a WMS for
example.)

So given this a possibility might be to have a georesource/service pair be the
handles to the centralized server.  A Layer will reference the georesource and a
tool can be developed that manipulates the data in the georesource.

That's one idea.  If you have other suggestions please let me know and I'll try
to provide some feedback.

Jesse