/**
* Extracts legend for layer based on LayerInfo configuration or style LegendGraphics.
*
* @param published FeatureType representing the layer
* @param w width for the image (hint)
* @param h height for the image (hint)
* @param transparent (should the image be transparent)
* @param request GetLegendGraphicRequest being built
* @return image with the title
*/
private RenderedImage getLayerLegend(
LegendRequest legend, int w, int h, boolean transparent, GetLegendGraphicRequest request) {
LegendInfo legendInfo = legend.getLegendInfo();
if (legendInfo == null) {
return null; // nothing provided will need to dynamically generate
}
String onlineResource = legendInfo.getOnlineResource();
if (onlineResource == null || onlineResource.isEmpty()) {
return null; // nothing provided will need to dynamically generate
}
URL url = null;
try {
url = new URL(onlineResource);
} catch (MalformedURLException invalid) {
LOGGER.fine("Unable to obtain " + onlineResource);
return null; // should log this!
}
try {
BufferedImage image = ImageIO.read(url);
if (image.getWidth() == w && image.getHeight() == h) {
return image;
}
final BufferedImage rescale = ImageUtils.createImage(w, h, (IndexColorModel) null, true);
Graphics2D g = (Graphics2D) rescale.getGraphics();
g.setColor(new Color(255, 255, 255, 0));
g.fillRect(0, 0, w, h);
double aspect = ((double) h) / ((double) image.getHeight());
int legendWidth = (int) (aspect * ((double) image.getWidth()));
g.drawImage(image, 0, 0, legendWidth, h, null);
g.dispose();
return rescale;
} catch (IOException notFound) {
LOGGER.log(Level.FINE, "Unable to legend graphic:" + url, notFound);
return null; // unable to access image
}
}
/**
* Writes layer LegendURL pointing to the user supplied icon URL, if any, or to the proper
* GetLegendGraphic operation if an URL was not supplied by configuration file.
*
* <p>It is common practice to supply a URL to a WMS accesible legend graphic when it is
* difficult to create a dynamic legend for a layer.
*
* @param ft The FeatureTypeInfo that holds the legendURL to write out, or<code>null</code> if
* dynamically generated.
* @task TODO: figure out how to unhack legend parameters such as WIDTH, HEIGHT and FORMAT
*/
protected void handleLegendURL(String layerName, LegendInfo legend, StyleInfo style) {
if (legend != null) {
if (LOGGER.isLoggable(Level.FINE)) {
LOGGER.fine("using user supplied legend URL");
}
AttributesImpl attrs = new AttributesImpl();
attrs.addAttribute("", "width", "width", "", String.valueOf(legend.getWidth()));
attrs.addAttribute("", "height", "height", "", String.valueOf(legend.getHeight()));
start("LegendURL", attrs);
element("Format", legend.getFormat());
attrs.clear();
attrs.addAttribute("", "xmlns:xlink", "xmlns:xlink", "", XLINK_NS);
attrs.addAttribute(XLINK_NS, "type", "xlink:type", "", "simple");
attrs.addAttribute(XLINK_NS, "href", "xlink:href", "", legend.getOnlineResource());
element("OnlineResource", null, attrs);
end("LegendURL");
} else {
String defaultFormat = GetLegendGraphicRequest.DEFAULT_FORMAT;
if (null == wmsConfig.getLegendGraphicOutputFormat(defaultFormat)) {
if (LOGGER.isLoggable(Level.WARNING)) {
LOGGER.warning(
new StringBuffer("Default legend format (")
.append(defaultFormat)
.append(")is not supported (jai not available?), can't add LegendURL element")
.toString());
}
return;
}
if (LOGGER.isLoggable(Level.FINE)) {
LOGGER.fine("Adding GetLegendGraphic call as LegendURL");
}
AttributesImpl attrs = new AttributesImpl();
attrs.addAttribute(
"", "width", "width", "", String.valueOf(GetLegendGraphicRequest.DEFAULT_WIDTH));
// DJB: problem here is that we do not know the size of the
// legend apriori - we need
// to make one and find its height. Not the best way, but it
// would work quite well.
// This was advertising a 20*20 icon, but actually producing
// ones of a different size.
// An alternative is to just scale the resulting icon to what
// the server requested, but this isnt
// the nicest thing since warped images dont look nice. The
// client should do the warping.
// however, to actually estimate the size is a bit difficult.
// I'm going to do the scaling
// so it obeys the what the request says. For people with a
// problem with that should consider
// changing the default size here so that the request is for the
// correct size.
attrs.addAttribute(
"", "height", "height", "", String.valueOf(GetLegendGraphicRequest.DEFAULT_HEIGHT));
start("LegendURL", attrs);
element("Format", defaultFormat);
attrs.clear();
Map<String, String> params =
params(
"request",
"GetLegendGraphic",
"format",
defaultFormat,
"width",
String.valueOf(GetLegendGraphicRequest.DEFAULT_WIDTH),
"height",
String.valueOf(GetLegendGraphicRequest.DEFAULT_HEIGHT),
"layer",
layerName);
if (style != null) {
params.put("style", style.getName());
}
String legendURL = buildURL(request.getBaseUrl(), "wms", params, URLType.SERVICE);
attrs.addAttribute("", "xmlns:xlink", "xmlns:xlink", "", XLINK_NS);
attrs.addAttribute(XLINK_NS, "type", "xlink:type", "", "simple");
attrs.addAttribute(XLINK_NS, "href", "xlink:href", "", legendURL);
element("OnlineResource", null, attrs);
end("LegendURL");
}
}