/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id$ */
package org.apache.fop.image.loader.batik;
import java.awt.geom.AffineTransform;
import java.io.IOException;
import java.io.InputStream;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMSource;
import org.w3c.dom.Element;
import org.w3c.dom.svg.SVGDocument;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.batik.anim.dom.SAXSVGDocumentFactory;
import org.apache.batik.anim.dom.SVGOMDocument;
import org.apache.batik.bridge.BridgeContext;
import org.apache.batik.bridge.DefaultFontFamilyResolver;
import org.apache.batik.bridge.UnitProcessor;
import org.apache.batik.bridge.UserAgent;
import org.apache.xmlgraphics.image.loader.ImageContext;
import org.apache.xmlgraphics.image.loader.ImageInfo;
import org.apache.xmlgraphics.image.loader.ImageSize;
import org.apache.xmlgraphics.image.loader.impl.AbstractImagePreloader;
import org.apache.xmlgraphics.image.loader.impl.ImageXMLDOM;
import org.apache.xmlgraphics.image.loader.util.ImageUtil;
import org.apache.xmlgraphics.io.XmlSourceUtil;
import org.apache.xmlgraphics.util.MimeConstants;
import org.apache.xmlgraphics.util.UnitConv;
import org.apache.fop.svg.SimpleSVGUserAgent;
import org.apache.fop.util.UnclosableInputStream;
/**
* Image preloader for SVG images.
*/
public class PreloaderSVG extends AbstractImagePreloader {
/** Logger instance */
private static Log log = LogFactory.getLog(PreloaderSVG.class);
private boolean batikAvailable = true;
/** {@inheritDoc} */
public ImageInfo preloadImage(String uri, Source src, ImageContext context)
throws IOException {
ImageInfo info = null;
if (batikAvailable) {
try {
Loader loader = new Loader();
if (!loader.isSupportedSource(src)) {
return null;
}
info = loader.getImage(uri, src, context);
} catch (NoClassDefFoundError e) {
batikAvailable = false;
log.warn("Batik not in class path", e);
return null;
}
}
if (info != null) {
XmlSourceUtil.closeQuietly(src); //Image is fully read
}
return info;
}
/**
* Returns the fully qualified classname of an XML parser for
* Batik classes that apparently need it (error messages, perhaps)
* @return an XML parser classname
*/
public static String getParserName() {
try {
SAXParserFactory factory = SAXParserFactory.newInstance();
return factory.newSAXParser().getXMLReader().getClass().getName();
} catch (Exception e) {
return null;
}
}
/**
* This method is put in another class so that the class loader does not
* attempt to load Batik related classes when constructing the SVGPreloader
* class.
*/
private final class Loader {
private Loader() {
}
private ImageInfo getImage(String uri, Source src,
ImageContext context) {
// parse document and get the size attributes of the svg element
InputStream in = null;
try {
SVGDocument doc;
if (src instanceof DOMSource) {
DOMSource domSrc = (DOMSource)src;
doc = (SVGDocument)domSrc.getNode();
} else {
in = new UnclosableInputStream(XmlSourceUtil.needInputStream(src));
int length = in.available();
in.mark(length + 1);
SAXSVGDocumentFactory factory = new SAXSVGDocumentFactory(
getParserName());
doc = factory.createSVGDocument(src.getSystemId(), in);
}
ImageInfo info = createImageInfo(uri, context, doc);
return info;
} catch (NoClassDefFoundError ncdfe) {
if (in != null) {
try {
in.reset();
} catch (IOException ioe) {
// we're more interested in the original exception
}
}
batikAvailable = false;
log.warn("Batik not in class path", ncdfe);
return null;
} catch (IOException e) {
// If the svg is invalid then it throws an IOException
// so there is no way of knowing if it is an svg document
log.debug("Error while trying to load stream as an SVG file: "
+ e.getMessage());
// assuming any exception means this document is not svg
// or could not be loaded for some reason
try {
in.reset();
} catch (IOException ioe) {
// we're more interested in the original exception
}
return null;
}
}
private ImageInfo createImageInfo(String uri, ImageContext context, SVGDocument doc) {
Element e = doc.getRootElement();
float pxUnitToMillimeter = UnitConv.IN2MM / context.getSourceResolution();
UserAgent userAg = new SimpleSVGUserAgent(pxUnitToMillimeter,
new AffineTransform(), DefaultFontFamilyResolver.SINGLETON) {
/** {@inheritDoc} */
public void displayMessage(String message) {
log.debug(message);
}
};
BridgeContext ctx = new BridgeContext(userAg);
UnitProcessor.Context uctx = UnitProcessor.createContext(ctx, e);
String s;
// 'width' attribute - default is 100%
s = e.getAttributeNS(null, SVGOMDocument.SVG_WIDTH_ATTRIBUTE);
if (s.length() == 0) {
s = SVGOMDocument.SVG_SVG_WIDTH_DEFAULT_VALUE;
}
float width = UnitProcessor.svgHorizontalLengthToUserSpace(
s, SVGOMDocument.SVG_WIDTH_ATTRIBUTE, uctx);
// 'height' attribute - default is 100%
s = e.getAttributeNS(null, SVGOMDocument.SVG_HEIGHT_ATTRIBUTE);
if (s.length() == 0) {
s = SVGOMDocument.SVG_SVG_HEIGHT_DEFAULT_VALUE;
}
float height = UnitProcessor.svgVerticalLengthToUserSpace(
s, SVGOMDocument.SVG_HEIGHT_ATTRIBUTE, uctx);
int widthMpt = (int)Math.round(px2mpt(width, context.getSourceResolution()));
int heightMpt = (int)Math.round(px2mpt(height, context.getSourceResolution()));
ImageInfo info = new ImageInfo(uri, MimeConstants.MIME_SVG);
ImageSize size = new ImageSize();
size.setSizeInMillipoints(widthMpt, heightMpt);
//Set the resolution to that of the FOUserAgent
size.setResolution(context.getSourceResolution());
size.calcPixelsFromSize();
info.setSize(size);
//The whole image had to be loaded for this, so keep it
ImageXMLDOM xmlImage = new ImageXMLDOM(info,
doc, BatikImageFlavors.SVG_DOM);
info.getCustomObjects().put(ImageInfo.ORIGINAL_IMAGE, xmlImage);
return info;
}
private boolean isSupportedSource(Source src) {
if (src instanceof DOMSource) {
DOMSource domSrc = (DOMSource)src;
return (domSrc.getNode() instanceof SVGDocument);
} else {
return ImageUtil.hasInputStream(src);
}
}
}
private static double px2mpt(double px, double resolution) {
return px * 1000 * UnitConv.IN2PT / resolution;
}
}