Re: [Geotools-gt2-users] Special rendering of the point layer

[Andrea A. <and...@ge...>]

On Wed, Jun 20, 2012 at 2:36 AM, Michael Bedward
<mic...@gm...>wrote:

> Hi Sergey,
>
> I don't know of an existing solution but it sounds like something that
> could be done by writing a process class and using it in a rendering
> transformation:
>
> http://docs.codehaus.org/display/GEOTOOLS/Rendering+transformations
>
> I'm copying this to Andrea who is the guru in this area.
>

Yep, a rendering transformation would do the job, thought it's not really
necessary
if you are in control of the data sources.

What I mean is, one could ask the data source to do the sorting of the
points via Query.setSortBy,
so that they are already in the right order, and then write a wrapping
feature collection
whose feature iterator builds on the fly the lines from the points.

On trunk I've added some time ago a base class that helps in setting up
this kind of on
the fly transformations:
http://svn.osgeo.org/geotools/trunk/modules/unsupported/process-feature/src/main/java/org/geotools/process/feature/gs/ProcessingCollection.java
http://svn.osgeo.org/geotools/trunk/modules/unsupported/process-feature/src/main/java/org/geotools/process/feature/gs/SimpleProcessingCollection.java<http://svn.osgeo.org/geotools/trunk/modules/unsupported/process-feature/src/main/java/org/geotools/process/feature/gs/ProcessingCollection.java>

Here is a process that uses is internally, one does not need to write the
process per se, it is sufficient to write the collection itself:
http://svn.osgeo.org/geotools/trunk/modules/unsupported/process-feature/src/main/java/org/geotools/process/feature/gs/BufferFeatureCollection.java<http://svn.osgeo.org/geotools/trunk/modules/unsupported/process-feature/src/main/java/org/geotools/process/feature/gs/ProcessingCollection.java>

and then feed the feature collection as the data source for a layer.

Cheers
Andrea

-- 
Ing. Andrea Aime
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