/**
 * <copyright> Copyright 2006 by Know-Center, Graz, Austria </copyright>
 * PDF-AS has been contracted by the E-Government Innovation Center EGIZ, a
 * joint initiative of the Federal Chancellery Austria and Graz University of
 * Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 */
package at.gv.egiz.pdfas.framework.input.correction;

import at.gv.egiz.pdfas.exceptions.framework.CorrectorException;
import at.gv.egiz.pdfas.framework.input.PdfDataSource;

/**
 * Interface for PDF corretors.
 * 
 * <p>
 * Often PDF documents generated by various document to PDF converters have an
 * invalid structure that upsets PDF-AS. The correction mechanism allows these
 * documents to be corrected before being signed.
 * </p>
 * <p>
 * A PDF corrector takes an incorrect PDF document and transforms it into a
 * correct one.
 * </p>
 * <p>
 * Note that correcting a document destroys all signatures in that document, so
 * never correct an already signed document.
 * </p>
 * 
 * @author wprinz
 */
public interface Corrector
{
  /**
   * Corrects the given PDF document to a form that PDF-AS can use.
   * 
   * @param document
   *          The (incorrect) PDF document.
   * @return Returns the corrected PDF document.
   * @throws CorrectorException
   *           Exception thrown if the document couldn't be corrected.
   */
  public PdfDataSource correctDocument(PdfDataSource document) throws CorrectorException;

}