Fwd: [Proj4j] Question About Valid CRS Identifiers To Get Started With GUI Development

[Martin Davis]

ditto


---------- Forwarded message ----------
From: Martin Davis <mtnclimb at gmail.com>
Date: Thu, Feb 25, 2010 at 8:50 PM
Subject: Re: [Proj4j] Question About Valid CRS Identifiers To Get
Started With GUI Development
To: Sunburned Surveyor <sunburned.surveyor at gmail.com>


Landon,

Re the the handling of CRS descriptions.  I see the parsing and model
of CRSes working like this:

- the Proj4FileReader will read a given input file in "PROJ4 format"
into a list of CRS objects.
- a CRS object will have an authority code, an id within the authority
namespace, and a textual description.  (This is pretty much
implemented now)
- The UI can provide whatever views of that list (or lists - one for
each input file = authority) is required.  I can see a need for at
least a view which shows the Auth, ID, and Desc all together.  It
might be nice to be able to sort by ID or description - although it's
probably more useful to provide text search within descriptions

So I don't think there's a need for a separate CRSIdentifier class -
the current CRS class has everything needed.  The views of this are
where much work is needed - typically defining and presenting these
kinds of views and search capabilities are much more work than the
underlying model.

HTH...


On Wed, Feb 24, 2010 at 4:47 PM, Sunburned Surveyor
<sunburned.surveyor at gmail.com> wrote:

> When you say "current file parser" do you mean the Proj4FileReader
> class? I took a look at the source code for that class today. The
> readFile method looks pretty scary. Do you want me to add the
> functionality I need to extract CRS identifiers from the NAD files to
> that class or to a different class? I'm thinking of two methods like:
>
> public List<String> getFormalCRSIdentifiers()
> public List<String> getFriendlyCRSIdentifiers()
>
> I can also see a need for two methods like:
>
> public String getFormalCRSIdentifierForFriendlyCRSIdentifier()
> public String getFriendlyCRSIdentifierForFormalCRSIdentifier()
>
> But those could be put into a utility class. Do you want to package
> the authority code, formal identifier, and friendly identifier in its
> own CrsIdentifier class, or is that getting two complicated? We could
> start using the CrsIdentifier class in the GUI and then use it later
> in the rest of the library if desired.