/*
* 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: PreloaderWMF.java 611278 2008-01-11 19:50:53Z jeremias $ */
package org.apache.fop.image.loader.batik;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.xml.transform.Source;
import org.apache.batik.transcoder.wmf.WMFConstants;
import org.apache.batik.transcoder.wmf.tosvg.WMFRecordStore;
import org.apache.commons.io.EndianUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
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.util.ImageUtil;
import org.apache.fop.util.UnclosableInputStream;
/**
* Image preloader for WMF images (Windows Metafile).
*/
public class PreloaderWMF extends AbstractImagePreloader {
/** Logger instance */
private static Log log = LogFactory.getLog(PreloaderWMF.class);
private boolean batikAvailable = true;
/** {@inheritDoc} */
public ImageInfo preloadImage(String uri, Source src, ImageContext context)
throws IOException {
if (!ImageUtil.hasInputStream(src)) {
return null;
}
ImageInfo info = null;
if (batikAvailable) {
try {
Loader loader = new Loader();
info = loader.getImage(uri, src, context);
} catch (NoClassDefFoundError e) {
batikAvailable = false;
log.warn("Batik not in class path", e);
return null;
}
}
if (info != null) {
ImageUtil.closeQuietly(src); //Image is fully read
}
return info;
}
/**
* This method is put in another class so that the class loader does not
* attempt to load Batik related classes when constructing the WMFPreloader
* class.
*/
class Loader {
private ImageInfo getImage(String uri, Source src,
ImageContext context) {
// parse document and get the size attributes of the svg element
InputStream in = new UnclosableInputStream(ImageUtil.needInputStream(src));
try {
in.mark(4 + 1);
DataInputStream din = new DataInputStream(in);
int magic = EndianUtils.swapInteger(din.readInt());
din.reset();
if (magic != WMFConstants.META_ALDUS_APM) {
return null; //Not a WMF file
}
WMFRecordStore wmfStore = new WMFRecordStore();
wmfStore.read(din);
IOUtils.closeQuietly(din);
int width = wmfStore.getWidthUnits();
int height = wmfStore.getHeightUnits();
int dpi = wmfStore.getMetaFileUnitsPerInch();
ImageInfo info = new ImageInfo(uri, "image/x-wmf");
ImageSize size = new ImageSize();
size.setSizeInPixels(width, height);
size.setResolution(dpi);
size.calcSizeFromPixels();
info.setSize(size);
ImageWMF img = new ImageWMF(info, wmfStore);
info.getCustomObjects().put(ImageInfo.ORIGINAL_IMAGE, img);
return info;
} catch (NoClassDefFoundError ncdfe) {
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 WMF 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;
}
}
}
}