[OpenLayers-Users] 3 questions

[Christopher Schmidt]

On Fri, Dec 19, 2008 at 11:56:08AM -0000, Joao Duarte wrote:
> Hello,
> 
> I’ve recently started using OpenLayers and I have 3 questions:

> 1.       I’ve been using the “resize” transition effect on my base layer.
> However the effect doesn’t occur in every zoom in/out. Am I missing
> something or the transition effect still has some issues?

The latter. The transition effects are, unfortunately, very touchy, and
despite many hours of work, we haven't found ways to amke them better.

> 2.       A have many types of data to display over the map. One of those is
> KML. In the KML file I want to represent there’s a “GroundOverlay” element
> which defines as image to overlap onto the map. I can’t find the support for
> this type of elements in the KML parser. Are there any plans for this or
> some kind of workaround?

KML is a complex format. What it describes is really an entire
OpenLayers app unto itself: movement commands, multiple layers, sets of
'tiles', etc. OpenLayers does not, at this point, have full support for
KML, and there are no plans for such.

Some other users have expressed interest in groundoverlays specifically.
I would not be against having a more complex KML parser, with a wrapper
around it that created the multiple layers needed, and so on. However,
this has not yet been started, and ould be a significant development
effort.  

> 3.       Another type of data I want to display on the map are some district
> shapes, defined in GeoJSON. The parser handles it fine and the shapes are
> represented on the map: http://img241.imageshack.us/img241/6856/img1vj0.jpg
> . However when I zoom in, the shapes of the islands at the left become
> visible when they should not, since the islands themselves are not visible
> on the map http://img120.imageshack.us/img120/930/img2lt8.jpg . Anyone has
> some ideas about what could be the problem?

Sounds very much like http://trac.openlayers.org/ticket/1782 .

If you are using 2.7, you can override this bug with the following code:

http://trac.openlayers.org/wiki/Patches/1782

You should include this code in your page after OpenLayers has been
loaded.

Regards,
-- 
Christopher Schmidt
MetaCarta