Java tutorial
/* * 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: ResourceHandler.java 1357883 2012-07-05 20:29:53Z gadams $ */ package org.apache.fop.render.ps; import java.awt.geom.Dimension2D; import java.awt.geom.Rectangle2D; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.Iterator; import java.util.Map; import java.util.Set; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.xmlgraphics.image.loader.ImageException; import org.apache.xmlgraphics.image.loader.ImageFlavor; import org.apache.xmlgraphics.image.loader.ImageInfo; import org.apache.xmlgraphics.image.loader.ImageManager; import org.apache.xmlgraphics.image.loader.ImageSessionContext; import org.apache.xmlgraphics.image.loader.util.ImageUtil; import org.apache.xmlgraphics.ps.DSCConstants; import org.apache.xmlgraphics.ps.FormGenerator; import org.apache.xmlgraphics.ps.PSGenerator; import org.apache.xmlgraphics.ps.PSResource; import org.apache.xmlgraphics.ps.dsc.DSCException; import org.apache.xmlgraphics.ps.dsc.DSCFilter; import org.apache.xmlgraphics.ps.dsc.DSCListener; import org.apache.xmlgraphics.ps.dsc.DSCParser; import org.apache.xmlgraphics.ps.dsc.DSCParserConstants; import org.apache.xmlgraphics.ps.dsc.DefaultNestedDocumentHandler; import org.apache.xmlgraphics.ps.dsc.ResourceTracker; import org.apache.xmlgraphics.ps.dsc.events.DSCComment; import org.apache.xmlgraphics.ps.dsc.events.DSCCommentBoundingBox; import org.apache.xmlgraphics.ps.dsc.events.DSCCommentDocumentNeededResources; import org.apache.xmlgraphics.ps.dsc.events.DSCCommentDocumentSuppliedResources; import org.apache.xmlgraphics.ps.dsc.events.DSCCommentHiResBoundingBox; import org.apache.xmlgraphics.ps.dsc.events.DSCCommentIncludeResource; import org.apache.xmlgraphics.ps.dsc.events.DSCCommentLanguageLevel; import org.apache.xmlgraphics.ps.dsc.events.DSCCommentPage; import org.apache.xmlgraphics.ps.dsc.events.DSCCommentPages; import org.apache.xmlgraphics.ps.dsc.events.DSCEvent; import org.apache.xmlgraphics.ps.dsc.events.DSCHeaderComment; import org.apache.xmlgraphics.ps.dsc.events.PostScriptComment; import org.apache.xmlgraphics.ps.dsc.events.PostScriptLine; import org.apache.xmlgraphics.ps.dsc.tools.DSCTools; import org.apache.fop.ResourceEventProducer; import org.apache.fop.apps.FOUserAgent; import org.apache.fop.fonts.FontInfo; import org.apache.fop.render.ImageHandler; import org.apache.fop.render.ImageHandlerRegistry; /** * This class is used when two-pass production is used to generate the PostScript file (setting * "optimize-resources"). It uses the DSC parser from XML Graphics Commons to go over the * temporary file generated by the PSRenderer and adds all used fonts and images as resources * to the PostScript file. */ public class ResourceHandler implements DSCParserConstants, PSSupportedFlavors { /** logging instance */ private static Log log = LogFactory.getLog(ResourceHandler.class); private FOUserAgent userAgent; private FontInfo fontInfo; private PSEventProducer eventProducer; private ResourceTracker resTracker; //key: URI, values PSImageFormResource private Map globalFormResources = new java.util.HashMap(); //key: PSResource, values PSImageFormResource private Map inlineFormResources = new java.util.HashMap(); /** * Main constructor. * @param userAgent the FO user agent * @param eventProducer the event producer * @param fontInfo the font information * @param resTracker the resource tracker to use * @param formResources Contains all forms used by this document (maintained by PSRenderer) */ public ResourceHandler(FOUserAgent userAgent, PSEventProducer eventProducer, FontInfo fontInfo, ResourceTracker resTracker, Map formResources) { this.userAgent = userAgent; this.eventProducer = eventProducer; this.fontInfo = fontInfo; this.resTracker = resTracker; determineInlineForms(formResources); } /** * This method splits up the form resources map into two. One for global forms which * have been referenced more than once, and one for inline forms which have only been * used once. The latter is to conserve memory in the PostScript interpreter. * @param formResources the original form resources map */ private void determineInlineForms(Map formResources) { if (formResources == null) { return; } Iterator iter = formResources.entrySet().iterator(); while (iter.hasNext()) { Map.Entry entry = (Map.Entry) iter.next(); PSResource res = (PSResource) entry.getValue(); long count = resTracker.getUsageCount(res); if (count > 1) { //Make global form this.globalFormResources.put(entry.getKey(), res); } else { //Inline resource this.inlineFormResources.put(res, res); resTracker.declareInlined(res); } } } /** * Rewrites the temporary PostScript file generated by PSRenderer adding all needed resources * (fonts and images). * @param in the InputStream for the temporary PostScript file * @param out the OutputStream to write the finished file to * @param pageCount the number of pages (given here because PSRenderer writes an "(atend)") * @param documentBoundingBox the document's bounding box * (given here because PSRenderer writes an "(atend)") * @throws DSCException If there's an error in the DSC structure of the PS file * @throws IOException In case of an I/O error */ public void process(InputStream in, OutputStream out, int pageCount, Rectangle2D documentBoundingBox) throws DSCException, IOException { DSCParser parser = new DSCParser(in); PSGenerator gen = new PSGenerator(out); parser.addListener(new DefaultNestedDocumentHandler(gen)); parser.addListener(new IncludeResourceListener(gen)); //Skip DSC header DSCHeaderComment header = DSCTools.checkAndSkipDSC30Header(parser); header.generate(gen); parser.setFilter(new DSCFilter() { private final Set filtered = new java.util.HashSet(); { //We rewrite those as part of the processing filtered.add(DSCConstants.PAGES); filtered.add(DSCConstants.BBOX); filtered.add(DSCConstants.HIRES_BBOX); filtered.add(DSCConstants.DOCUMENT_NEEDED_RESOURCES); filtered.add(DSCConstants.DOCUMENT_SUPPLIED_RESOURCES); } public boolean accept(DSCEvent event) { if (event.isDSCComment()) { //Filter %%Pages which we add manually from a parameter return !(filtered.contains(event.asDSCComment().getName())); } else { return true; } } }); //Get PostScript language level (may be missing) while (true) { DSCEvent event = parser.nextEvent(); if (event == null) { reportInvalidDSC(); } if (DSCTools.headerCommentsEndHere(event)) { //Set number of pages DSCCommentPages pages = new DSCCommentPages(pageCount); pages.generate(gen); new DSCCommentBoundingBox(documentBoundingBox).generate(gen); new DSCCommentHiResBoundingBox(documentBoundingBox).generate(gen); PSFontUtils.determineSuppliedFonts(resTracker, fontInfo, fontInfo.getUsedFonts()); registerSuppliedForms(resTracker, globalFormResources); //Supplied Resources DSCCommentDocumentSuppliedResources supplied = new DSCCommentDocumentSuppliedResources( resTracker.getDocumentSuppliedResources()); supplied.generate(gen); //Needed Resources DSCCommentDocumentNeededResources needed = new DSCCommentDocumentNeededResources( resTracker.getDocumentNeededResources()); needed.generate(gen); //Write original comment that ends the header comments event.generate(gen); break; } if (event.isDSCComment()) { DSCComment comment = event.asDSCComment(); if (DSCConstants.LANGUAGE_LEVEL.equals(comment.getName())) { DSCCommentLanguageLevel level = (DSCCommentLanguageLevel) comment; gen.setPSLevel(level.getLanguageLevel()); } } event.generate(gen); } //Skip to the FOPFontSetup PostScriptComment fontSetupPlaceholder = parser.nextPSComment("FOPFontSetup", gen); if (fontSetupPlaceholder == null) { throw new DSCException("Didn't find %FOPFontSetup comment in stream"); } PSFontUtils.writeFontDict(gen, fontInfo, fontInfo.getUsedFonts(), eventProducer); generateForms(globalFormResources, gen); //Skip the prolog and to the first page DSCComment pageOrTrailer = parser.nextDSCComment(DSCConstants.PAGE, gen); if (pageOrTrailer == null) { throw new DSCException("Page expected, but none found"); } //Process individual pages (and skip as necessary) while (true) { DSCCommentPage page = (DSCCommentPage) pageOrTrailer; page.generate(gen); pageOrTrailer = DSCTools.nextPageOrTrailer(parser, gen); if (pageOrTrailer == null) { reportInvalidDSC(); } else if (!DSCConstants.PAGE.equals(pageOrTrailer.getName())) { pageOrTrailer.generate(gen); break; } } //Write the rest while (parser.hasNext()) { DSCEvent event = parser.nextEvent(); event.generate(gen); } gen.flush(); } private static void reportInvalidDSC() throws DSCException { throw new DSCException("File is not DSC-compliant: Unexpected end of file"); } private static void registerSuppliedForms(ResourceTracker resTracker, Map formResources) throws IOException { if (formResources == null) { return; } Iterator iter = formResources.values().iterator(); while (iter.hasNext()) { PSImageFormResource form = (PSImageFormResource) iter.next(); resTracker.registerSuppliedResource(form); } } private void generateForms(Map formResources, PSGenerator gen) throws IOException { if (formResources == null) { return; } Iterator iter = formResources.values().iterator(); while (iter.hasNext()) { PSImageFormResource form = (PSImageFormResource) iter.next(); generateFormForImage(gen, form); } } private void generateFormForImage(PSGenerator gen, PSImageFormResource form) throws IOException { final String uri = form.getImageURI(); ImageManager manager = userAgent.getFactory().getImageManager(); ImageInfo info = null; try { ImageSessionContext sessionContext = userAgent.getImageSessionContext(); info = manager.getImageInfo(uri, sessionContext); //Create a rendering context for form creation PSRenderingContext formContext = new PSRenderingContext(userAgent, gen, fontInfo, true); ImageFlavor[] flavors; ImageHandlerRegistry imageHandlerRegistry = userAgent.getFactory().getImageHandlerRegistry(); flavors = imageHandlerRegistry.getSupportedFlavors(formContext); Map hints = ImageUtil.getDefaultHints(sessionContext); org.apache.xmlgraphics.image.loader.Image img = manager.getImage(info, flavors, hints, sessionContext); ImageHandler basicHandler = imageHandlerRegistry.getHandler(formContext, img); if (basicHandler == null) { throw new UnsupportedOperationException("No ImageHandler available for image: " + img.getInfo() + " (" + img.getClass().getName() + ")"); } if (!(basicHandler instanceof PSImageHandler)) { throw new IllegalStateException("ImageHandler implementation doesn't behave properly." + " It should have returned false in isCompatible(). Class: " + basicHandler.getClass().getName()); } PSImageHandler handler = (PSImageHandler) basicHandler; if (log.isTraceEnabled()) { log.trace("Using ImageHandler: " + handler.getClass().getName()); } handler.generateForm(formContext, img, form); } catch (ImageException ie) { ResourceEventProducer eventProducer = ResourceEventProducer.Provider .get(userAgent.getEventBroadcaster()); eventProducer.imageError(resTracker, (info != null ? info.toString() : uri), ie, null); } } private static FormGenerator createMissingForm(String formName, final Dimension2D dimensions) { FormGenerator formGen = new FormGenerator(formName, null, dimensions) { protected void generatePaintProc(PSGenerator gen) throws IOException { gen.writeln("0 setgray"); gen.writeln("0 setlinewidth"); String w = gen.formatDouble(dimensions.getWidth()); String h = gen.formatDouble(dimensions.getHeight()); gen.writeln(w + " " + h + " scale"); gen.writeln("0 0 1 1 rectstroke"); gen.writeln("newpath"); gen.writeln("0 0 moveto"); gen.writeln("1 1 lineto"); gen.writeln("stroke"); gen.writeln("newpath"); gen.writeln("0 1 moveto"); gen.writeln("1 0 lineto"); gen.writeln("stroke"); } }; return formGen; } private class IncludeResourceListener implements DSCListener { private PSGenerator gen; public IncludeResourceListener(PSGenerator gen) { this.gen = gen; } /** {@inheritDoc} */ public void processEvent(DSCEvent event, DSCParser parser) throws IOException, DSCException { if (event.isDSCComment() && event instanceof DSCCommentIncludeResource) { DSCCommentIncludeResource include = (DSCCommentIncludeResource) event; PSResource res = include.getResource(); if (res.getType().equals(PSResource.TYPE_FORM)) { if (inlineFormResources.containsValue(res)) { PSImageFormResource form = (PSImageFormResource) inlineFormResources.get(res); //Create an inline form //Wrap in save/restore pair to release memory gen.writeln("save"); generateFormForImage(gen, form); boolean execformFound = false; DSCEvent next = parser.nextEvent(); if (next.isLine()) { PostScriptLine line = next.asLine(); if (line.getLine().endsWith(" execform")) { line.generate(gen); execformFound = true; } } if (!execformFound) { throw new IOException("Expected a PostScript line in the form: <form> execform"); } gen.writeln("restore"); } else { //Do nothing } parser.next(); } } } } }