[Kstars-devel] UID for skyobjects proposal

[Alexey Khudyakov]

On Tue, Jul 7, 2009 at 6:19 PM, Akarsh Simha<akarshsimha at gmail.com> wrote:
>
> Shouldn't we also have some sort of classification based on catalog?
> Suppose in the future, we decide to support a variety of object
> catalogs - Caldwell, UGC, PGC, Herschel, Collinder etc, our system
> should work even there.
>
> I was wondering if it would be better to classify deep-sky objects
> based on catalog rather than by type.
>
> I have no objections to this.
>
No I think UID should be generally independent of catalog.

One object could belong to many catalogs: HD/SAO/GSC or Messie/NGC/PGC
etc. Ideally we should be able to display information from all
catalogs, add them if needed. It's one to many correspondence (one
object <=> many catalogs). So I don't think it's really good idea.

I think better idea is to keep only essential information in
SkyObject. For stars it's RA/dec, magnitude, proper motion, color
index. Everything else could be loaded on request. For example when
details dialog is viewed. There could be problems with matching UIDs
between catalogs with searching. I think design space is rather big.

With this scheme it would be possible to get rid of ugly if ladders in
DeepSkyComponent. I mean:
  if( object is Messie) {
    ...
  }else if(object is NGC) {
    ...