de.intarsys.pdf.cos.COSTools Maven / Gradle / Ivy

Go to download
/*
 * Copyright (c) 2007, intarsys consulting GmbH
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * - Neither the name of intarsys nor the names of its contributors may be used
 *   to endorse or promote products derived from this software without specific
 *   prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package de.intarsys.pdf.cos;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import de.intarsys.pdf.parser.COSLoadException;
import de.intarsys.pdf.parser.PDFParser;
import de.intarsys.pdf.st.STDocument;
import de.intarsys.pdf.st.STXRefSection;
import de.intarsys.tools.locator.ILocator;
import de.intarsys.tools.locator.LocatorViewport;
import de.intarsys.tools.randomaccess.IRandomAccess;

/**
 * Some tools to ease life with COS.
 */
public class COSTools {

	public static class Revision {
		private STXRefSection xRefSection;
		private long length;

		public ILocator createLocator() {
			LocatorViewport locator = new LocatorViewport(getXRefSection()
					.getDoc().getLocator());
			locator.setName(getXRefSection().getDoc().getLocator()
					.getLocalName()
					+ "_v" + getXRefSection().getIncrementalCount() + ".pdf"); //$NON-NLS-1$ //$NON-NLS-2$
			locator.setStart(0);
			locator.setEnd(getLength());
			locator.setReadOnly();
			return locator;
		}

		public long getLength() {
			return length;
		}

		public STXRefSection getXRefSection() {
			return xRefSection;
		}

		public void setLength(long length) {
			this.length = length;
		}

		public void setXRefSection(STXRefSection refSection) {
			xRefSection = refSection;
		}
	}

	/**
	 * Try the best in marshalling java objects directly to {@link COSObject}.
	 * Collections will be marshalled recursively.
	 * 
	 * @param javaObject
	 *            the java object to be marshalled
	 * @deprecated use {@link COSConverter}
	 * @return The resulting {@link COSObject}
	 */
	@Deprecated
	static public COSObject createObject(Object javaObject) {
		return COSConverter.toCos(javaObject);
	}

	public static List getRevisions(COSDocument doc)
			throws IOException, COSLoadException {
		List result = new ArrayList();
		STDocument stDoc = doc.stGetDoc();
		STXRefSection xRef = stDoc.getXRefSection();
		if (stDoc.getRandomAccess() == null) {
			return result;
		}
		List offsetSortedXRefs = new ArrayList();
		while (xRef != null) {
			offsetSortedXRefs.add(xRef);
			xRef = xRef.getPrevious();
		}
		Collections.sort(offsetSortedXRefs, new Comparator() {
			public int compare(STXRefSection o1, STXRefSection o2) {
				if (o1.getOffset() < o2.getOffset()) {
					return 1;
				} else if (o1.getOffset() > o2.getOffset()) {
					return -1;
				}
				return 0;
			}
		});

		long lastEnd = -1;
		for (STXRefSection section : offsetSortedXRefs) {
			COSDictionary cosDict = section.cosGetDict();
			if (!cosDict.get(COSTrailer.DK_Root).isNull()) {
				// the dummy trailer in a linearized pdf does not need /Root
				long limit = lastEnd;
				if (limit == -1) {
					limit = stDoc.getRandomAccess().getLength();
				}
				long end = searchNextEOF(stDoc.getRandomAccess(), section
						.getOffset(), limit);
				// if (end != -1 && lastEnd != end) {
				if (end != -1) {
					Revision revision = new Revision();
					revision.setXRefSection(section);
					revision.setLength(end);
					result.add(revision);
					lastEnd = end;
				}
			}
		}
		Collections.reverse(result);
		return result;
	}

	public static List getSubsequentRevisions(COSDocument doc,
			STXRefSection base) throws IOException, COSLoadException {
		List revisions = getRevisions(doc);
		List result = new ArrayList();
		boolean include = false;
		for (Revision revision : revisions) {
			if (include) {
				result.add(revision);
			} else {
				if (revision.getXRefSection() == base) {
					include = true;
				}
			}
		}
		return result;
	}

	/**
	 * A collection of {@link ILocator} instances, representing the versions
	 * created when writing incrementally.
	 * 
	 * @param doc
	 *            The original document.
	 * @return A collection of {@link ILocator} instances, representing the
	 *         versions created when writing incrementally.
	 * @throws IOException
	 * @throws COSLoadException
	 */
	static public List getVersions(COSDocument doc)
			throws IOException, COSLoadException {
		List revisions = getRevisions(doc);
		List result = new ArrayList();
		for (Revision revision : revisions) {
			result.add(revision.createLocator());
		}
		return result;
	}

	static protected boolean readUptoNewLine(IRandomAccess input)
			throws IOException {
		int i;
		while (true) {
			i = input.read();
			if (i == -1) {
				return false;
			}
			if (PDFParser.isEOL(i)) {
				if (i == PDFParser.CHAR_CR) {
					i = input.read();
					if (i != PDFParser.CHAR_LF) {
						input.seekBy(-1);
					}
				}
				return true;
			}
		}
	}

	static protected long searchNextEOF(IRandomAccess input, long start,
			long end) throws IOException, COSLoadException {
		input.seek(start);
		int comparisonIndex = 0;
		for (int i = input.read(); (i != -1) && (input.getOffset() < end); i = input
				.read()) {
			if (i == PDFParser.TOKEN_EOF[comparisonIndex]) {
				comparisonIndex++;
				if (comparisonIndex == PDFParser.TOKEN_EOF.length) {
					readUptoNewLine(input);
					return input.getOffset();
				}
			} else {
				comparisonIndex = 0;
			}
		}
		return -1;
	}

	/**
	 * Tries to force a dictionary out of the COSObject.
	 * 
	 * @param object
	 *            The object to be cast to a {@link COSDictionary}
	 * @return {@link COSDictionary} or null
	 */
	public static COSDictionary toDictionary(COSObject object) {
		COSDictionary dict = null;
		if (object instanceof COSDictionary) {
			dict = (COSDictionary) object;
		} else if (object instanceof COSStream) {
			dict = ((COSStream) object).getDict();
		}
		return dict;
	}

	private COSTools() {
		super();
	}
}