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/*
* 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.merger.merge;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.openoffice.xmerge.ConverterCapabilities;
import org.openoffice.xmerge.MergeException;
import org.openoffice.xmerge.merger.MergeAlgorithm;
import org.openoffice.xmerge.merger.NodeMergeAlgorithm;
import org.openoffice.xmerge.merger.Iterator;
import org.openoffice.xmerge.merger.Difference;
import org.openoffice.xmerge.util.XmlUtil;
/**
* This is an implementation of the {@code MergeAlgorithm} interface.
*
* <p>This class will merge two {@code Document} classes. It utilizes the
* appropriate class which implements {@link
* org.openoffice.xmerge.merger.NodeMergeAlgorithm NodeMergeAlgorithm} to
* perform the merge.</p>
*/
public class DocumentMerge implements MergeAlgorithm {
private final NodeMergeAlgorithm subDocumentMerge;
/** The capabilities of this converter. */
protected ConverterCapabilities cc_;
/**
* Constructor.
*
* @param cc The {@code ConverterCapabilities}.
* @param merge The {@code NodeMergeAlgorithm}.
*/
public DocumentMerge(ConverterCapabilities cc, NodeMergeAlgorithm merge) {
cc_ = cc;
subDocumentMerge = merge;
}
public void applyDifference(Iterator orgSeq, Iterator modSeq,
Difference[] differences) throws MergeException {
// a quick test whether the differences array is in ascending order
int currentPosition = -1;
boolean haveDeleteOperation = false;
for (Difference difference : differences) {
if (difference.getOrgPosition() > currentPosition) {
currentPosition = difference.getOrgPosition();
haveDeleteOperation = difference.getOperation() == Difference.DELETE;
} else if (difference.getOrgPosition() == currentPosition) {
if (difference.getOperation() == Difference.DELETE) {
haveDeleteOperation = true;
} else if (difference.getOperation() == Difference.ADD &&
haveDeleteOperation) {
throw new MergeException(
"Differences array is not sorted. Delete before Add");
}
} else {
throw new MergeException("Differences array need to be sorted.");
}
}
// reset sequence counters
orgSeq.start();
int orgSeqCounter = 0;
modSeq.start();
int modSeqCounter = 0;
// check for each diff unit in the diff array to apply the diff
for (Difference currentDiff : differences) {
int operation = currentDiff.getOperation();
switch (operation) {
case Difference.DELETE:
// loop through the original sequence up to the expected
// position. note that we use delta (see above comment)
// also. we will just continue the counter without reset it.
for (;
orgSeqCounter < currentDiff.getOrgPosition();
orgSeqCounter++, orgSeq.next()) {
// empty
}
// remove the Node. note that it will NOT affect the
// iterator sequence as ParaNodeIterator is a static one.
removeNode((Node)(orgSeq.currentElement()));
break;
// if it's an add operation, then get content from original seq
case Difference.ADD:
// loop through the modified sequence up to the expected
// position to get the content. As we don't need to modify
// the sequence. we don't need to use delta to do adjustment.
for (;
modSeqCounter < currentDiff.getModPosition();
modSeqCounter++, modSeq.next()) {
// empty
}
for (;
orgSeqCounter < currentDiff.getOrgPosition();
orgSeqCounter++, orgSeq.next()) {
// empty
}
if (orgSeqCounter > orgSeq.elementCount() - 1) {
// append the element to the end of the original sequence
appendNode((Node)(orgSeq.currentElement()),
(Node)(modSeq.currentElement()));
} else {
// insert the element BEFORE the current element
insertNode((Node)(orgSeq.currentElement()),
(Node)(modSeq.currentElement()));
}
break;
case Difference.CHANGE:
for (;
modSeqCounter < currentDiff.getModPosition();
modSeqCounter++, modSeq.next()) {
// empty
}
for (;
orgSeqCounter < currentDiff.getOrgPosition();
orgSeqCounter++, orgSeq.next()) {
// empty
}
if (subDocumentMerge == null) {
// use a simple replace if no row merge algorithm supply
replaceElement((Element)orgSeq.currentElement(),
(Element)modSeq.currentElement());
} else {
subDocumentMerge.merge((Element)orgSeq.currentElement(),
(Element)modSeq.currentElement());
}
break;
default:
break;
}
}
}
/**
* Removes the specified {@code Node}.
*
* @param node {@code Node} to remove.
*/
protected void removeNode(Node node) {
Node parent = node.getParentNode();
parent.removeChild(node);
}
/**
* Appends {@code Node} after the specified {@code Node}.
*
* @param oldNode {@code Node} to append after.
* @param newNode {@code Node} to append.
*/
private void appendNode(Node oldNode, Node newNode) {
Node clonedNode = XmlUtil.deepClone(oldNode, newNode);
Node parent = oldNode.getParentNode();
parent.appendChild(clonedNode);
}
/**
* Insert {@code Node} before the specified {@code Node}.
*
* @param oldNode {@code Node} to insert before.
* @param newNode {@code Node} to insert.
*/
private void insertNode(Node oldNode, Node newNode) {
Node clonedNode = XmlUtil.deepClone(oldNode, newNode);
Node parent = oldNode.getParentNode();
parent.insertBefore(clonedNode, oldNode);
}
/**
* Replace <code>Element</code>.
*
* @param currElem {@code Element} to be replaced.
* @param newElem {@code Element} to replace.
*/
private void replaceElement(Element currElem, Element newElem) {
Node clonedNode = XmlUtil.deepClone(currElem, newElem);
Node parent = currElem.getParentNode();
parent.replaceChild(clonedNode, currElem);
}
}
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