[mapguide-internals] MapGuide RFC 15 - New Query Features API

Bruce Dechant bruce.dechant at autodesk.com
Fri Feb 2 19:13:08 EST 2007


The following assumes you are using the existing API.

The selected parcels only show up if you zoom/pan after you have already
selected them. As soon as you do a new selection at the zoomed out level
where the parcels are not visible they will not be selected. This is
more for convenience so that you can see a parcel you have selected
while you zoom to more of an overview display.

Now if you are not careful with the NEW API you could end up with lots
of features selected. :)


-----Original Message-----
From: mapguide-internals-bounces at lists.osgeo.org
[mailto:mapguide-internals-bounces at lists.osgeo.org] On Behalf Of Jason
Sent: February 2, 2007 5:06 PM
To: MapGuide Internals Mail List
Subject: RE: [mapguide-internals] MapGuide RFC 15 - New Query Features

I think this is a great idea, but...

Will there be any way to disable this behaviour in the viewer?  I don't
know if I want selected parcels showing up on the map at extreme zoom
levels.  Talk about ugly.

This is not a feature request.  From a cartographic standpoint I'd love
to see something like this:

Representation thresholds.  Set zoom levels where adjacent polygonal
features are merged into a single polygon, and then turn into a
symbolized point feature.  For instance, consider a Hospital:
- at 1:5000, all buildings in the hospital complex are represented, and
labelled with the word "Hospital"
- at 1:10000, these buildings are aggregated into a single rubber-band
polygon, labelled with the letter "H" in a blue circle
- at 1:15000, the hospital is represented by a letter H in a blue
circle, positioned at the center of gravity of the original features

The trick is that all just different representations of the same
feature, so selection would be maintained, and geometry operations would
be applied to the true geometry, not the simplified representation.

I'm already doing this to a certain extent manually, but it would be
nice to not have to maintain multiple copies of the same data just for
display's sake, and with this method there is no way of maintaining
selection status from one scale range to the next.


-----Original Message-----
Subject: [mapguide-internals] MapGuide RFC 15 - New Query Features API

Hi Everyone,

We would like to submit the following RFC for open discussion and


Please respond to the list with any feedback and we will be happy to


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