| /************************************************************** |
| * |
| * 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. |
| * |
| *************************************************************/ |
| |
| |
| |
| package org.openoffice.xmerge.merger.diff; |
| |
| import org.w3c.dom.Node; |
| import org.w3c.dom.NodeList; |
| import org.w3c.dom.NamedNodeMap; |
| |
| import org.openoffice.xmerge.ConverterCapabilities; |
| import org.openoffice.xmerge.merger.Iterator; |
| import org.openoffice.xmerge.util.Debug; |
| import org.openoffice.xmerge.util.Resources; |
| |
| import java.util.Vector; |
| import java.util.List; |
| |
| |
| /** |
| * <p>This is an implementation of the <code>Iterator</code> interface. |
| * It will traverse the tree and find <code>Node</code> sequences.</p> |
| * |
| * <p>Note: Once the XML Tree is parsed, then the <code>Iterator</code> will |
| * be a snap shot of that tree. That means even the tree is modified later, |
| * than the cached paragraph <code>Node</code> list will not be updated |
| * accordingly. For this reason and for performance reasons this |
| * <code>Iterator</code> does not support any operation methods such as |
| * insert, remove or replace. The main purpose of this |
| * <code>Iterator</code> is to be used with difference, not with merge.</p> |
| * |
| * @author smak |
| */ |
| public abstract class NodeIterator implements Iterator { |
| |
| private List nodeList = null; |
| private int currentPosition = 0; |
| private Node root; |
| private ConverterCapabilities cc_ = null; |
| |
| |
| /** |
| * Standard constructor. |
| * |
| * @param cc The <code>ConverterCapabilities</code>. |
| * @param node The initial root <code>Node</code>. |
| */ |
| public NodeIterator(ConverterCapabilities cc, Node node) { |
| cc_ = cc; |
| nodeList = new Vector(); |
| root = node; |
| markTree(node); |
| } |
| |
| |
| public Object next() { |
| if (currentPosition < nodeList.size() - 1) { |
| currentPosition++; |
| return currentElement(); |
| } else { |
| return null; |
| } |
| } |
| |
| |
| public Object previous() { |
| if (currentPosition > 0) { |
| currentPosition--; |
| return currentElement(); |
| } else { |
| return null; |
| } |
| } |
| |
| |
| public Object start() { |
| currentPosition = 0; |
| return currentElement(); |
| } |
| |
| |
| public Object end() { |
| int size = nodeList.size(); |
| |
| if (size > 0) { |
| currentPosition = size - 1; |
| return currentElement(); |
| } else { |
| return null; |
| } |
| } |
| |
| |
| public Object currentElement() { |
| |
| if (currentPosition < 0 || currentPosition >= nodeList.size()) { |
| return null; |
| } |
| |
| return nodeList.get(currentPosition); |
| } |
| |
| |
| public int elementCount() { |
| return nodeList.size(); |
| } |
| |
| |
| public boolean equivalent(Object obj1, Object obj2) { |
| boolean equal = false; |
| String errMsg = null; |
| if (!(obj1 instanceof Node && obj2 instanceof Node)) { |
| errMsg = Resources.getInstance().getString("NOT_NODE_ERROR"); |
| Debug.log(Debug.ERROR, errMsg); |
| } else { |
| Node node1 = (Node)obj1; |
| Node node2 = (Node)obj2; |
| |
| equal = compareNode(node1, node2); |
| } |
| return equal; |
| } |
| |
| |
| public void refresh() { |
| nodeList = new Vector(); |
| markTree(root); |
| currentPosition = 0; |
| } |
| |
| |
| /** |
| * Used to compare two <code>Node</code> objects (type/name/value) |
| * and all their children <code>Node</code> objects. |
| * |
| * @param node1 The first <code>Node</code> to compare. |
| * @param node2 The second <code>Node</code> to compare. |
| * |
| * @return true if <code>Node</code> is equal, false otherwise. |
| */ |
| protected boolean compareNode(Node node1, Node node2) { |
| boolean equal = false; |
| |
| nodeCheck: { |
| |
| if (node1 == null || node2 == null) { |
| break nodeCheck; |
| } |
| |
| // nodevalue is short |
| if (node1.getNodeType() != node2.getNodeType()) { |
| break nodeCheck; |
| } |
| |
| // nodeName will not be null |
| if (!node1.getNodeName().equals(node2.getNodeName())) { |
| break nodeCheck; |
| } |
| |
| // nodeValue can be null for a lot of type of cells |
| if (node1.getNodeValue() == null && node2.getNodeValue() == null) { |
| // empty |
| } else if (node1.getNodeValue() == null || |
| node2.getNodeValue() == null) { |
| break nodeCheck; |
| } else if (!node1.getNodeValue().equals(node2.getNodeValue())) { |
| break nodeCheck; |
| } |
| |
| // try to compare attributes |
| if (!attributesEqual(node1, node2)) { |
| break nodeCheck; |
| } |
| |
| // don't need to compare if both node do not have children |
| if (!node1.hasChildNodes() && !node2.hasChildNodes()) { |
| equal = true; |
| break nodeCheck; |
| // don't need to compare if one node has children but not the other |
| } else if (!node1.hasChildNodes() || !node2.hasChildNodes()) { |
| equal = false; |
| break nodeCheck; |
| // need to compare if both node has children |
| } else if (!childrenEqual(node1, node2)) { |
| break nodeCheck; |
| } |
| |
| equal = true; |
| } |
| |
| return equal; |
| } |
| |
| |
| /** |
| * Compare the children of two <code>Node</code> objects. This |
| * method can be intentionally overridden by any class that |
| * extend from <code>NodeIterator</code> so that it can have |
| * its own children comparison if necessary. |
| * |
| * @param node1 The first <code>Node</code> to compare. |
| * @param node2 The second <code>Node</code> to compare. |
| * |
| * @return true if children are equal, false otherwise. |
| */ |
| protected boolean childrenEqual(Node node1, Node node2) { |
| |
| boolean equal = false; |
| |
| childrenCheck: { |
| NodeList node1Children = node1.getChildNodes(); |
| NodeList node2Children = node2.getChildNodes(); |
| |
| if (node1Children == null || node2Children == null) { |
| break childrenCheck; |
| } |
| |
| if (node1Children.getLength() != node2Children.getLength()) { |
| break childrenCheck; |
| } |
| |
| // compare all the childrens |
| equal = true; |
| |
| for (int i = 0; i < node1Children.getLength(); i++) { |
| if (!compareNode(node1Children.item(i), |
| node2Children.item(i))) { |
| equal = false; |
| break childrenCheck; |
| } |
| } |
| } |
| |
| return equal; |
| } |
| |
| |
| /** |
| * Compare attributes of two <code>Node</code> objects. This |
| * method can be intentionally overridden by any class that |
| * extends from <code>NodeIterator</code> so that it can have |
| * its own attribute comparison. |
| * |
| * @param node1 The first <code>Node</code> to compare. |
| * @param node2 The second <code>Node</code> to compare. |
| * |
| * @return true if attributes are equal, false otherwise. |
| */ |
| protected boolean attributesEqual(Node node1, Node node2) { |
| |
| boolean equal = false; |
| String nodeName = node1.getNodeName(); |
| NamedNodeMap attrNode[] = new NamedNodeMap[2]; |
| attrNode[0] = node1.getAttributes(); |
| attrNode[1] = node2.getAttributes(); |
| |
| // attribute node will be null if node is not an element node |
| // and attribute nodes are equal if both are not element node |
| if (attrNode[0] == null || attrNode[1] == null) { |
| if (attrNode[0] == null && attrNode[1] == null) { |
| equal = true; |
| } |
| return equal; |
| } |
| |
| // compare the attributes from node1 vs node2 and node2 vs node1 |
| // though it's a little inefficient for the duplication of comparison |
| // as the number of attributes is not so many, it should not be |
| // a big problem. |
| int len [] = new int[2]; |
| int src, dst; |
| |
| attrCheck: { |
| for (int i = 0; i < 2; i++) { |
| |
| if (i == 0) { |
| src = 0; |
| dst = 1; |
| } else { |
| src = 1; |
| dst = 0; |
| } |
| |
| len[src] = attrNode[src].getLength(); |
| |
| for (int j = 0; j < len[src]; j++) { |
| Node srcAttr = attrNode[src].item(j); |
| String srcAttrName = srcAttr.getNodeName(); |
| |
| // copy the supported attrs |
| if (cc_ == null || |
| cc_.canConvertAttribute(nodeName, srcAttrName)) { |
| |
| // check whether the attribute exist in dst node |
| Node dstAttr = attrNode[dst].getNamedItem(srcAttrName); |
| |
| if (dstAttr == null) { |
| Debug.log(Debug.INFO, |
| "[NodeIterator] Attr not exist in dst - " |
| + srcAttrName); |
| break attrCheck; |
| } |
| |
| // then compare the attribute values |
| if (!srcAttr.getNodeValue().equals( |
| dstAttr.getNodeValue())) { |
| Debug.log(Debug.INFO, |
| "[NodeIterator] Attr diff src: " + |
| srcAttr.getNodeValue() + " dst: "+ |
| dstAttr.getNodeValue()); |
| break attrCheck; |
| } |
| } // end if cc_ loop |
| } // end for j loop |
| } // end for i loop |
| |
| // the whole checking is done smoothly and all attributes are equal |
| equal = true; |
| } |
| |
| return equal; |
| } |
| |
| |
| /** |
| * Check whether a <code>Node</code> is supported. This method |
| * can be intentionally overridden by any class that extends from |
| * <code>NodeIterator</code> so that it can specify which |
| * <code>Node</code> to support. |
| * |
| * @param node <code>Node</code> to check. |
| * |
| * @return true if <code>Node</code> is supported, false otherwise. |
| */ |
| protected abstract boolean nodeSupported(Node node); |
| |
| // doing a depth first search for the tree and mark all supported nodes |
| private void markTree(Node node) { |
| |
| // if this is a supported node, then we add it to our cache table |
| if (nodeSupported(node)) { |
| nodeList.add(node); |
| } else { |
| // or we go through all children nodes recursively |
| // (can be optimized in future) |
| String nodeName = node.getNodeName(); |
| if ( cc_ == null || cc_.canConvertTag(nodeName)) { |
| NodeList nodeList = node.getChildNodes(); |
| int nodeListLength = nodeList.getLength(); |
| for (int i = 0; i < nodeListLength; i++) { |
| markTree(nodeList.item(i)); |
| } |
| } |
| else { |
| Debug.log(Debug.INFO, " [NodeIterator::markTree] Skipping node " |
| + nodeName); |
| } |
| } |
| } |
| } |
| |