/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org. All rights reserved.
* This code is licensed under the GPL 2.0 license, availible at the root
* application directory.
*/
package org.geoserver.wms.legendgraphic;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.awt.image.IndexColorModel;
import java.awt.image.RenderedImage;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.geoserver.platform.ServiceException;
import org.geoserver.wms.GetLegendGraphicRequest;
import org.geoserver.wms.map.ImageUtils;
import org.geotools.data.DataUtilities;
import org.geotools.feature.SchemaException;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.geometry.jts.LiteShape2;
import org.geotools.renderer.lite.StyledShapePainter;
import org.geotools.renderer.style.SLDStyleFactory;
import org.geotools.renderer.style.Style2D;
import org.geotools.styling.Description;
import org.geotools.styling.FeatureTypeStyle;
import org.geotools.styling.LineSymbolizer;
import org.geotools.styling.PointSymbolizer;
import org.geotools.styling.PolygonSymbolizer;
import org.geotools.styling.RasterSymbolizer;
import org.geotools.styling.Rule;
import org.geotools.styling.Style;
import org.geotools.styling.Symbolizer;
import org.geotools.styling.TextSymbolizer;
import org.geotools.util.NumberRange;
import org.opengis.feature.Feature;
import org.opengis.feature.IllegalAttributeException;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.feature.type.FeatureType;
import org.opengis.util.InternationalString;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LineString;
import com.vividsolutions.jts.geom.LinearRing;
import com.vividsolutions.jts.geom.Polygon;
/**
* Template {@linkPlain org.vfny.geoserver.responses.wms.GetLegendGraphicProducer} based on
* GeoTools' {@link GeoTools' {@link http
* ://svn.geotools.org/geotools/trunk/gt/module/main/src/org/geotools
* /renderer/lite/StyledShapePainter.java StyledShapePainter} that produces a BufferedImage with the
* appropiate legend graphic for a given GetLegendGraphic WMS request.
*
* <p>
* It should be enough for a subclass to implement {@linkPlain
* org.vfny.geoserver.responses.wms.GetLegendGraphicProducer#writeTo(OutputStream)} and
* <code>getContentType()</code> in order to encode the BufferedImage produced by this class to the
* appropiate output format.
* </p>
*
* <p>
* This class takes literally the fact that the arguments <code>WIDTH</code> and <code>HEIGHT</code>
* are just <i>hints</i> about the desired dimensions of the produced graphic, and the need to
* produce a legend graphic representative enough of the SLD style for which it is being generated.
* Thus, if no <code>RULE</code> parameter was passed and the style has more than one applicable
* Rule for the actual scale factor, there will be generated a legend graphic of the specified
* width, but with as many stacked graphics as applicable rules were found, providing by this way a
* representative enough legend.
* </p>
*
* @author Gabriel Roldan
* @author Simone Giannecchini, GeoSolutions SAS
* @version $Id: BufferedImageLegendGraphicBuilder.java 15163 2010-12-13 16:38:00Z aaime $
*/
public class BufferedImageLegendGraphicBuilder {
/** Factory that will resolve symbolizers into rendered styles */
private static final SLDStyleFactory styleFactory = new SLDStyleFactory();
/** Tolerance used to compare doubles for equality */
public static final double TOLERANCE = 1e-6;
/**
* Singleton shape painter to serve all legend requests. We can use a single shape painter
* instance as long as it remains thread safe.
*/
private static final StyledShapePainter shapePainter = new StyledShapePainter();
/**
* used to create sample point shapes with LiteShape (not lines nor polygons)
*/
private static final GeometryFactory geomFac = new GeometryFactory();
/**
* set to <code>true</code> when <code>abort()</code> gets called, indicates that the rendering
* of the legend graphic should stop gracefully as soon as possible
*/
private boolean renderingStopRequested;
/**
* Just a holder to avoid creating many polygon shapes from inside <code>getSampleShape()</code>
*/
private LiteShape2 sampleRect;
/**
* Just a holder to avoid creating many line shapes from inside <code>getSampleShape()</code>
*/
private LiteShape2 sampleLine;
/**
* Just a holder to avoid creating many point shapes from inside <code>getSampleShape()</code>
*/
private LiteShape2 samplePoint;
/**
* Default constructor. Subclasses may provide its own with a String parameter to establish its
* desired output format, if they support more than one (e.g. a JAI based one)
*/
public BufferedImageLegendGraphicBuilder() {
super();
}
/**
* Takes a GetLegendGraphicRequest and produces a BufferedImage that then can be used by a
* subclass to encode it to the appropiate output format.
*
* @param request
* the "parsed" request, where "parsed" means that it's values are already validated
* so this method must not take care of verifying the requested layer exists and the
* like.
* @return
*
* @throws ServiceException
* if there are problems creating a "sample" feature instance for the FeatureType
* <code>request</code> returns as the required layer (which should not occur).
*/
public BufferedImage buildLegendGraphic(GetLegendGraphicRequest request)
throws ServiceException {
final Style gt2Style = request.getStyle();
if (gt2Style == null) {
throw new NullPointerException("request.getStyle()");
}
final FeatureType layer = request.getLayer();
boolean strict = request.isStrict();
final boolean buildRasterLegend = (!strict && layer == null && LegendUtils
.checkRasterSymbolizer(gt2Style)) || LegendUtils.checkGridLayer(layer);
if (buildRasterLegend) {
final RasterLayerLegendHelper rasterLegendHelper = new RasterLayerLegendHelper(request);
final BufferedImage image = rasterLegendHelper.getLegend();
return image;
}
final SimpleFeature sampleFeature;
if (layer == null) {
sampleFeature = createSampleFeature();
} else {
final Feature temp = createSampleFeature(layer);
if (!(temp instanceof SimpleFeature)) {
throw new UnsupportedOperationException("not a SimpleFeature");
}
sampleFeature = (SimpleFeature) temp;
}
final FeatureTypeStyle[] ftStyles = gt2Style.featureTypeStyles().toArray(
new FeatureTypeStyle[0]);
final double scaleDenominator = request.getScale();
final Rule[] applicableRules;
if (request.getRule() != null) {
applicableRules = new Rule[] { request.getRule() };
} else {
applicableRules = LegendUtils.getApplicableRules(ftStyles, scaleDenominator);
}
final NumberRange<Double> scaleRange = NumberRange.create(scaleDenominator,
scaleDenominator);
final int ruleCount = applicableRules.length;
/**
* A legend graphic is produced for each applicable rule. They're being held here until the
* process is done and then painted on a "stack" like legend.
*/
final List<RenderedImage> legendsStack = new ArrayList<RenderedImage>(ruleCount);
final int w = request.getWidth();
final int h = request.getHeight();
final Color bgColor = LegendUtils.getBackgroundColor(request);
for (int i = 0; i < ruleCount; i++) {
final Symbolizer[] symbolizers = applicableRules[i].getSymbolizers();
// BufferedImage image = prepareImage(w, h, request.isTransparent());
final boolean transparent = request.isTransparent();
final RenderedImage image = ImageUtils.createImage(w, h, (IndexColorModel) null,
transparent);
final Map<RenderingHints.Key, Object> hintsMap = new HashMap<RenderingHints.Key, Object>();
final Graphics2D graphics = ImageUtils.prepareTransparency(transparent, bgColor, image,
hintsMap);
graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
for (int sIdx = 0; sIdx < symbolizers.length; sIdx++) {
final Symbolizer symbolizer = symbolizers[sIdx];
if (symbolizer instanceof RasterSymbolizer) {
throw new IllegalStateException(
"It is not legal to have a RasterSymbolizer here");
} else {
Style2D style2d = styleFactory.createStyle(sampleFeature, symbolizer,
scaleRange);
LiteShape2 shape = getSampleShape(symbolizer, w, h);
if (style2d != null) {
shapePainter.paint(graphics, shape, style2d, scaleDenominator);
}
}
}
legendsStack.add(image);
graphics.dispose();
}
// JD: changed legend behavior, see GEOS-812
// this.legendGraphic = scaleImage(mergeLegends(legendsStack), request);
BufferedImage image = mergeLegends(legendsStack, applicableRules, request);
return image;
}
/**
* Recieves a list of <code>BufferedImages</code> and produces a new one which holds all the
* images in <code>imageStack</code> one above the other.
*
* @param imageStack
* the list of BufferedImages, one for each applicable Rule
* @param rules
* The applicable rules, one for each image in the stack
* @param request
* The request.
*
* @return the stack image with all the images on the argument list.
*
* @throws IllegalArgumentException
* if the list is empty
*/
private static BufferedImage mergeLegends(List<RenderedImage> imageStack, Rule[] rules,
GetLegendGraphicRequest req) {
Font labelFont = LegendUtils.getLabelFont(req);
boolean useAA = false;
if (req.getLegendOptions().get("fontAntiAliasing") instanceof String) {
String aaVal = (String) req.getLegendOptions().get("fontAntiAliasing");
if (aaVal.equalsIgnoreCase("on") || aaVal.equalsIgnoreCase("true")
|| aaVal.equalsIgnoreCase("yes") || aaVal.equalsIgnoreCase("1")) {
useAA = true;
}
}
boolean forceLabelsOn = false;
boolean forceLabelsOff = false;
if (req.getLegendOptions().get("forceLabels") instanceof String) {
String forceLabelsOpt = (String) req.getLegendOptions().get("forceLabels");
if (forceLabelsOpt.equalsIgnoreCase("on")) {
forceLabelsOn = true;
} else if (forceLabelsOpt.equalsIgnoreCase("off")) {
forceLabelsOff = true;
}
}
if (imageStack.size() == 0) {
throw new IllegalArgumentException("No legend graphics passed");
}
final BufferedImage finalLegend;
if (imageStack.size() == 1 && !forceLabelsOn) {
finalLegend = (BufferedImage) imageStack.get(0);
} else {
final int imgCount = imageStack.size();
final String[] labels = new String[imgCount];
BufferedImage img = ((BufferedImage) imageStack.get(0));
int totalHeight = 0;
int totalWidth = 0;
int[] rowHeights = new int[imgCount];
BufferedImage labelsGraphics[] = new BufferedImage[imgCount];
for (int i = 0; i < imgCount; i++) {
img = (BufferedImage) imageStack.get(i);
if (forceLabelsOff) {
totalWidth = (int) Math.ceil(Math.max(img.getWidth(), totalWidth));
rowHeights[i] = img.getHeight();
totalHeight += img.getHeight();
} else {
Rule rule = rules[i];
// What's the label on this rule? We prefer to use
// the 'title' if it's available, but fall-back to 'name'
final Description description = rule.getDescription();
if (description != null && description.getTitle() != null) {
final InternationalString title = description.getTitle();
labels[i] = title.toString();
} else if (rule.getName() == null) {
labels[i] = rule.getName();
} else {
labels[i] = "";
}
Graphics2D g = img.createGraphics();
g.setFont(labelFont);
if (useAA) {
g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
} else {
g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_OFF);
}
if (labels[i] != null && labels[i].length() > 0) {
final BufferedImage renderedLabel = LegendUtils.renderLabel(labels[i], g,
req);
labelsGraphics[i] = renderedLabel;
final Rectangle2D bounds = new Rectangle2D.Double(0, 0,
renderedLabel.getWidth(), renderedLabel.getHeight());
totalWidth = (int) Math.ceil(Math.max(img.getWidth() + bounds.getWidth(),
totalWidth));
rowHeights[i] = (int) Math.ceil(Math.max(img.getHeight(),
bounds.getHeight()));
} else {
totalWidth = (int) Math.ceil(Math.max(img.getWidth(), totalWidth));
rowHeights[i] = (int) Math.ceil(img.getHeight());
labelsGraphics[i] = null;
}
totalHeight += rowHeights[i];
}
}
// buffer the width a bit
totalWidth += 2;
final boolean transparent = req.isTransparent();
final Color backgroundColor = LegendUtils.getBackgroundColor(req);
final Map<RenderingHints.Key, Object> hintsMap = new HashMap<RenderingHints.Key, Object>();
// create the final image
finalLegend = ImageUtils.createImage(totalWidth, totalHeight, (IndexColorModel) null,
transparent);
Graphics2D finalGraphics = ImageUtils.prepareTransparency(transparent, backgroundColor,
finalLegend, hintsMap);
int topOfRow = 0;
for (int i = 0; i < imgCount; i++) {
img = (BufferedImage) imageStack.get(i);
// draw the image
int y = topOfRow;
if (img.getHeight() < rowHeights[i]) {
// move the image to the center of the row
y += (int) ((rowHeights[i] - img.getHeight()) / 2d);
}
finalGraphics.drawImage(img, 0, y, null);
if (forceLabelsOff) {
topOfRow += rowHeights[i];
continue;
}
finalGraphics.setFont(labelFont);
if (useAA) {
finalGraphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
} else {
finalGraphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_OFF);
}
// draw the label
if (labels[i] != null && labels[i].length() > 0) {
// first create the actual overall label image.
final BufferedImage renderedLabel = labelsGraphics[i];
y = topOfRow;
if (renderedLabel.getHeight() < rowHeights[i]) {
y += (int) ((rowHeights[i] - renderedLabel.getHeight()) / 2d);
}
finalGraphics.drawImage(renderedLabel, img.getWidth(), y, null);
// cleanup
renderedLabel.flush();
labelsGraphics[i] = null;
}
topOfRow += rowHeights[i];
}
finalGraphics.dispose();
}
return finalLegend;
}
/**
* Returns a <code>java.awt.Shape</code> appropiate to render a legend graphic given the
* symbolizer type and the legend dimensions.
*
* @param symbolizer
* the Symbolizer for whose type a sample shape will be created
* @param legendWidth
* the requested width, in output units, of the legend graphic
* @param legendHeight
* the requested height, in output units, of the legend graphic
*
* @return an appropiate Line2D, Rectangle2D or LiteShape(Point) for the symbolizer, wether it
* is a LineSymbolizer, a PolygonSymbolizer, or a Point ot Text Symbolizer
*
* @throws IllegalArgumentException
* if an unknown symbolizer impl was passed in.
*/
private LiteShape2 getSampleShape(Symbolizer symbolizer, int legendWidth, int legendHeight) {
LiteShape2 sampleShape;
final float hpad = (legendWidth * LegendUtils.hpaddingFactor);
final float vpad = (legendHeight * LegendUtils.vpaddingFactor);
if (symbolizer instanceof LineSymbolizer) {
if (this.sampleLine == null) {
Coordinate[] coords = { new Coordinate(hpad, legendHeight - vpad),
new Coordinate(legendWidth - hpad, vpad) };
LineString geom = geomFac.createLineString(coords);
try {
this.sampleLine = new LiteShape2(geom, null, null, false);
} catch (Exception e) {
this.sampleLine = null;
}
}
sampleShape = this.sampleLine;
} else if ((symbolizer instanceof PolygonSymbolizer)
|| (symbolizer instanceof RasterSymbolizer)) {
if (this.sampleRect == null) {
final float w = legendWidth - (2 * hpad);
final float h = legendHeight - (2 * vpad);
Coordinate[] coords = { new Coordinate(hpad, vpad), new Coordinate(hpad, vpad + h),
new Coordinate(hpad + w, vpad + h), new Coordinate(hpad + w, vpad),
new Coordinate(hpad, vpad) };
LinearRing shell = geomFac.createLinearRing(coords);
Polygon geom = geomFac.createPolygon(shell, null);
try {
this.sampleRect = new LiteShape2(geom, null, null, false);
} catch (Exception e) {
this.sampleRect = null;
}
}
sampleShape = this.sampleRect;
} else if (symbolizer instanceof PointSymbolizer || symbolizer instanceof TextSymbolizer) {
if (this.samplePoint == null) {
Coordinate coord = new Coordinate(legendWidth / 2, legendHeight / 2);
try {
this.samplePoint = new LiteShape2(geomFac.createPoint(coord), null, null, false);
} catch (Exception e) {
this.samplePoint = null;
}
}
sampleShape = this.samplePoint;
} else {
throw new IllegalArgumentException("Unknown symbolizer: " + symbolizer);
}
return sampleShape;
}
private SimpleFeature createSampleFeature() {
SimpleFeatureType type;
try {
type = DataUtilities.createType("Sample", "the_geom:Geometry");
} catch (SchemaException e) {
throw new RuntimeException(e);
}
return SimpleFeatureBuilder.template((SimpleFeatureType) type, null);
}
/**
* Creates a sample Feature instance in the hope that it can be used in the rendering of the
* legend graphic.
*
* @param schema
* the schema for which to create a sample Feature instance
*
* @return
*
* @throws ServiceException
*/
private Feature createSampleFeature(FeatureType schema) throws ServiceException {
SimpleFeature sampleFeature;
try {
if (schema instanceof SimpleFeatureType) {
sampleFeature = SimpleFeatureBuilder.template((SimpleFeatureType) schema, null);
} else {
// TODO: implement support for GSIP 31 (DataAccess API)
throw new UnsupportedOperationException(
"Sample non-simple feature not yet supported.");
}
} catch (IllegalAttributeException e) {
throw new ServiceException(e);
}
return sampleFeature;
}
}