[udig-devel] Question on Renderers

[Ugo Taddei <ugo.taddei@xxxxxxxxxxxxxxxxxx>]

Hello,

I'm hopelessly trying to understand the rationale behind all those 
Renderers, RenderMetrics and RenderMetricsFactories. For that, I've 
adapted the code from StaticGISWidget and I'm trying to render onto an 
image I created.

I use ApplicationGIS.drawMap( drawParameters ) to render the image. It's 
not working because

Renderer renderer = decisive.getRenderer(context); (around line 855)

returns a net.refractions.udig.project.internal.render.impl.PlaceHolder, 
which apparently is some sort of dummy renderer, that is, does nothing.

In my application I read a project, and try to render a map (with the 
adapted code from StatcGisWidget). In the printlns I added, I only see a 
MapGraphicRenderMetricsFactory (which I assume is always there, as I 
don't have explicitely instantiated on or created one within the 
project). I cannot see any other renderes.

How does udig figures out, what sort of layer it has, say a shapefile, 
and when does it do that?

What renderer is responsible for the shapefiles, is it 
ShapefileFeatureRenderer?

Do I have to set the renderer myself?

Thanks in advance,

Ugo

--
Ugo Taddei

Fraunhofer Institut Intelligente Analyse- und Informationssysteme (FhG IAIS)
http://www.iais.fraunhofer.de
Department Knowledge Discovery - IAIS.KD -
Working Group Spatial Decision Support
http://www.iais.fraunhofer.de/kd.html
phone  (+49)2241-14-2184    fax    (+49)2241-14-2072
Schloss Birlinghoven, D-53754 Sankt Augustin, Germany