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TextSymbolizer - Some Labels Not Showing

3 messages

Kang Mann Ern

TextSymbolizer - Some Labels Not Showing

Reply Threaded

Some javascript/style in this post has been disabled (why?)

Hi,

I've been using GeoTools for some time now and I think it gives great results. However

I seem to be having some problems with TextSymbolizer.

Many labels, especially longer ones don't seem to be getting rendered. I have tried setting

the "spaceAround" option to negative values, which increases the number of labels displayed

(some of which overlap each other), but many labels are still not being rendered. Changing the

magnitude of the negative spaceAround value makes no difference. Changing the placement

also doesn't solve the problem.

I have even tried rendering with a single feature (I.e. only one label in the entire map), but still

the label does not show up.

I suspect this may be due to a predefined maximum size for labels, but I can't find any option

to override such a thing. Am I overlooking some option, or doing this in the wrong way?

Hope to get some ideas. Thanks a lot.

Code:

....

//create labels

TextSymbolizer textSym = styleBuilder.createTextSymbolizer(
Color.BLACK, styleBuilder.createFont("Arial", false, false, 9),
"building_n");
textSym.setHalo(styleBuilder.createHalo(Color.WHITE, 1));
textSym.setPlacement(styleBuilder.createPointPlacement(0.5, 0.5, 0, 0, 0));
textSym.addToOptions("spaceAround", "-1");

Rule rule4 = styleBuilder.createRule(textSym);

Rule[] rules = {rule, rule2, rule3, rule4};

FeatureTypeStyle featureTypeStyle = styleBuilder.
createFeatureTypeStyle("Feature", rules);

style.addFeatureTypeStyle(featureTypeStyle);

DefaultMapContext mc = new DefaultMapContext();
DefaultMapLayer layer = new DefaultMapLayer(intBdlgsCollection, style); //layer containing labels
DefaultMapLayer layer2 = new DefaultMapLayer(landlotCollection, style2);
mc.addLayer(layer2);
mc.addLayer(layer);

StreamingRenderer renderer = new StreamingRenderer();

renderer.setContext(mc);
java.awt.Rectangle rc = new java.awt.Rectangle();
rc.setBounds(0, 0, 1280, 800);
g2d.setColor(Color.BLUE); //fill background first
g2d.fillRect(0, 0, 1280, 800);

//render map
renderer.paint(g2d, rc,
new ReferencedEnvelope( 17500, 23000, 28000, 33437,
mc.getCoordinateReferenceSystem()));

Cheers,

Mann Ern

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Kang Mann Ern

Re: TextSymbolizer - Some Labels Not Showing

Reply Threaded

Some javascript/style in this post has been disabled (why?)

Hi,

I think its the fixed MIN_GOODNESS_FIT value used by LabelCacheDefault that's causing the

trouble. I've sidestepped this for now by passing a hint to StreamingRenderer to use

LabelCacheImpl instead - all labels are showing up now Smile emoticon

. It would be great if LabelCacheDefault

accepted an option to set MIN_GOODNESS_FIT instead of having it be a fixed constant value,

maybe I'll do it myself, if I manage to figure out how to compile the GeoTools library lol.

Anyway thanks to anyone who read my question and spared it some thought. GeoTools is getting

more and more fun to use!

Cheers,
Mann Ern

From: [hidden email]

Sent: Sunday, October 18, 2009 1:46 PM

To: [hidden email]

Subject: TextSymbolizer - Some Labels Not Showing

Hi,

I've been using GeoTools for some time now and I think it gives great results. However

I seem to be having some problems with TextSymbolizer.

Many labels, especially longer ones don't seem to be getting rendered. I have tried setting

the "spaceAround" option to negative values, which increases the number of labels displayed

(some of which overlap each other), but many labels are still not being rendered. Changing the

magnitude of the negative spaceAround value makes no difference. Changing the placement

also doesn't solve the problem.

I have even tried rendering with a single feature (I.e. only one label in the entire map), but still

the label does not show up.

I suspect this may be due to a predefined maximum size for labels, but I can't find any option

to override such a thing. Am I overlooking some option, or doing this in the wrong way?

Hope to get some ideas. Thanks a lot.

Code:

....

//create labels

Rule rule4 = styleBuilder.createRule(textSym);

Rule[] rules = {rule, rule2, rule3, rule4};

FeatureTypeStyle featureTypeStyle = styleBuilder.
createFeatureTypeStyle("Feature", rules);

style.addFeatureTypeStyle(featureTypeStyle);

StreamingRenderer renderer = new StreamingRenderer();

renderer.setContext(mc);
java.awt.Rectangle rc = new java.awt.Rectangle();
rc.setBounds(0, 0, 1280, 800);
g2d.setColor(Color.BLUE); //fill background first
g2d.fillRect(0, 0, 1280, 800);

//render map
renderer.paint(g2d, rc,
new ReferencedEnvelope( 17500, 23000, 28000, 33437,
mc.getCoordinateReferenceSystem()));

Cheers,

Mann Ern

mbedward

Re: TextSymbolizer - Some Labels Not Showing

Reply Threaded

Hi Mann Ern,

Thanks very much for posting the solution that you found to the list.

I just had a very quick look for this problem in the Jira issue tracker...

http://jira.codehaus.org/browse/GEOT

...but didn't find it.

If there's any chance of you creating a new Jira issue and providing a small data set and code snippet that illustrates the problem that would be super.

cheers

Michael