I'd extend OMGraphicHandlerLayer, rather than use PlugInLayer.
When you extend OMGraphicHandlerLayer, you override the prepare()
method to react to projection changes, and return the OMGraphicList
you want displayed for the new projection. You can call
getProjection() to get the current projection for use in prepare().
Don't forget to call generate(Projection) on the OMGraphics in the
list you return.
If you call getList() from within prepare(), it will return the
OMGraphicList currently being used by the layer. If that list is
null, you know prepare() is being called for the first time, which
also indicates the first time the layer is part of the map. This is a
good indicator of when to do initialization work.
It's good practice to always return a new OMGraphicList from the
prepare method, even if it means simply adding the same OMGraphics to
the new list. This is more important if there are a lot of repaints()
occurring.
I think I'd maks a simple layer for querying the server for the data
and build up an OMGrid object with the results. If performance
becomes an issue, I think I would move to the ImageTileLayer model,
with ImageTiles modified to make queries to the server and caching the
image results on a tile-by-tile basis.
Hope this helps,
Don
On Feb 19, 2009, at 12:52 PM, Sutphin, William B CIV NUWC NWPT wrote:
> I looked at the tutorials, thanks. I'm adding the layer to
> MapBean. Should
> I use PlugInLayer instead?
>
> OpenMap has a lot of fun stuff, its just sometimes hard to tie
> together or
> decide which of the many ways to do something.
>
> I started with the source to DTED layer, but I'm not convinced yet
> that this
> is the most apropos thing.
>
> Bill Sutphin
> Naval Undersea Warfare Center, Division Newport
> Bldg 1351, Room 211C
> Newport, RI 02841
> (401) 832-5813
> DSN 432-5813
>
>
>
>> -----Original Message-----
>> From: Guy Pascarella [mailto:guy.pascarella_at_issinc.com]
>> Sent: Friday, February 13, 2009 11:57
>> To: Sutphin, William B CIV NUWC NWPT; openmap-users_at_bbn.com
>> Subject: RE: [OpenMap Users] ASCII Lat Long Ht Data
>>
>> Bill,
>> Here are a couple of tutorials I wrote on how to write a plugin/
>> layer.
>> http://www.hazelnutcafe.net/tutorials/
>>
>> They may be helpful if you want to access the sounding data
>> directly instead of converting it into something like DTED.
>>
>> -Guy
>>
>>
>> -----Original Message-----
>> From: owner-openmap-users_at_bbn.com
>> [mailto:owner-openmap-users_at_bbn.com] On Behalf Of Sutphin,
>> William B CIV NUWC NWPT
>> Sent: Friday, February 13, 2009 9:54 AM
>> To: openmap-users_at_bbn.com
>> Subject: [OpenMap Users] ASCII Lat Long Ht Data
>>
>> Hi
>>
>> I have sounding data in Lat Lon Height ASCII format. Any
>> recommendations for the best way to display this in openmap?
>> Even if I write my own Layer derivative, do I use ImageLayer?
>> Its really more like DTED I would think.
>>
>> Thanks
>>
>> Bill Sutphin
>>
>>
--
[To unsubscribe to this list send an email to "majdart_at_bbn.com"
with the following text in the BODY of the message "unsubscribe openmap-users"]
Received on Fri Feb 20 2009 - 12:30:08 EST