/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   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 .
 */

package org.openoffice.xmerge;

/**
 * A {@code DocumentMerger} can merge changes from a modified "Device"
 * {@code Document} to the assigned original "Office" {@code Document}.
 *
 * <p>Merge is useful when an {@code OfficeDocument} is converted to a
 * &quot;Device&quot; {@code Document} format, and the &quot;Device&quot;
 * {@code Document} version is modified.  Those changes can be merged back into
 * the original {@code OfficeDocument} with the merger.  The merger is capable
 * of doing this even if the &quot;Device&quot; format is lossy in
 * comparison to the {@code OfficeDocument} format.</p>
 *
 * <p>The {@code ConverterCapabilities} object is what the DocumentMerger
 * utilizes to know how the &quot;Office&quot; {@code Document} tags are
 * supported in the &quot;Device&quot; format.</p>
 *
 * <p>The {@code DocumentMerger} object is created by the
 * {@code DocumentMergerFactory} {@link
 * org.openoffice.xmerge.DocumentMergerFactory#createDocumentMerger
 * createDocumenMerger} method.  When it is constructed, the &quot;Original
 * Office&quot; {@code Document} object is passed in to be used as input.</p>
 *
 * @see  org.openoffice.xmerge.PluginFactory
 * @see  org.openoffice.xmerge.DocumentMergerFactory
 * @see  org.openoffice.xmerge.ConverterCapabilities
 */
public interface DocumentMerger {

    /**
     * This method will find the changes that had happened in the
     * {@code modifiedDoc} {@code Document} object given the designated original
     * {@code Document}.
     *
     * <p>Note that this  process may need the knowledge of the conversion
     * process since some conversion process are lossy.  Items/Data that are
     * lost during the conversion process are not classified as changes.  The
     * main target of this method is to apply the changes done in
     * {@code modifiedDoc} into the assigned original {@code Document} object,
     * thus it also will try to preserve items that were originally in the
     * original {@code Document}, but never got transferred during the
     * {@link org.openoffice.xmerge.DocumentSerializer#serialize serialize}
     * process/method call.  After this method call, the original
     * {@code Document} object will contain the changes applied.</p>
     *
     * <p>This method may or may not be thread-safe.  Also, it is expected that
     * the user uses only one instance of a {@code DocumentMerger} object per
     * merge process.  Create another {@code DocumentMerger} object for another
     * merge process.</p>
     *
     * @param   modifiedDoc  device {@code Document} object.
     *
     * @throws  MergeException  If any merge error occurs.
     */
    void merge(Document modifiedDoc) throws MergeException;
}