[udig-devel] New Layer with filtered features (uDig, uDig...we have a problem!!!)

[Jesse Eichar]

Right off I see a problem.  It is that you are adding features to a  
visible layer.  What happens here is that each time a feature is  
added the map is re-rendered.  What you should do is what you do in  
the second email.  Add the features to the layer before the layer is  
added to the map.  Or setVisible to be false on the map....  Oh wait  
we just fixed a bug yesterday.  As of the next release setting the  
LayerVisibility to false will be sufficient but for now you have to  
add the features to a layer before it is in the map.  (Or use the  
CopyFeaturesCommand.

Jesse

On 17-Nov-06, at 12:52 AM, Javier Cámara wrote:

> Hi list!!!
>
> First of all ... a little presentation...
>
> We are developing a set of plugins which we want to upload to svn  
> as soon as possible.
>
> After that...we are trying to solve a set of problems, and a little  
> bit of help will be very appreciate.
>
> The most urgent problem is about a common task:
> 1) Take a layer with features
> 2) Filter the layer
> 3) Create a new layer with the filtered features
>
> Well, I know that it's 'solve' in lists and Codehaus, but we can't  
> do it run properly.
>
> We use the next sequence:
> ---------------------------------------------------------------------- 
> -----------------------------
> IGeoResource memoryRsc = CatalogPlugin.getDefault().getLocalCatalog()
>                             .createTemporaryResource 
> ( layer.getSchema());
>
> Layer newLayer = ((Map) layer.getMap()).getLayerFactory()
>                             .createLayer(memoryRsc);
>
> FeatureSource fsource = layer.getResource(FeatureSource.class, new  
> NullProgressMonitor());
> FeatureCollection filterColl = fsource.getFeatures(queryFilter);
>
> memoryRsc.resolve(FeatureStore.class, monitor).addFeatures 
> (filterColl);
> ---------------------------------------------------------------------- 
> -----------------------------
>
> If we try a layer with a reduced number of features (around 50  
> features) it's works fine,
> but...we try too with a heavy layer (around 50000 features) and the  
> result is very discouraging:
> the number of filtered features would be, for example, 20000, but  
> the new layer only has 400 elements.
>
> We don't know if the problem is the high number of elements,  
> because we check a breakpoint
> after the 'addFeatures' command and it don't stop the execution  
> with the heavy layer...with a lite
> layer, it works fine.
>
> For the people who is working in a similar case...do you try with a  
> high number of features?
>
> Tracing the geotools code (addFeatures method), we can see that it  
> use a FeatureWriter object and we try to model the same
> behavoiur in our code (iterator over the filterColl), but we think  
> that is a worng way...and we obtain the same results.
>
> Thanks for your time!!!
>
> Regards,
>
> -- 
> Javier Cámara
>
>
> E.P. Desarrollo Agrario y Pesquero
> C/ Bergantín 39
> Sevilla [ESPAÑA]
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