Optimized the loading of ODF files (the old xmerge code is completely rewritten)

git-svn-id: svn://svn.code.sf.net/p/writer2latex/code/trunk@144 f0f2a975-2e09-46c8-9428-3b39399b9f3c

source/java/writer2latex/util/SimpleDOMBuilder.java

@@ -0,0 +1,123 @@
+/************************************************************************
+ *
+ *  SimpleDOMBuilder.java
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License version 2.1, as published by the Free Software Foundation.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ *  MA  02111-1307  USA
+ *
+ *  Copyright: 2002-2012 by Henrik Just
+ *
+ *  All Rights Reserved.
+ * 
+ *  Version 1.4 (2012-03-22)
+ *
+ */
+
+package writer2latex.util;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+
+import org.w3c.dom.DOMImplementation;
+import org.w3c.dom.Document;
+import org.w3c.dom.DocumentType;
+import org.w3c.dom.Element;
+
+/** This class provides a simple way to create and populate a DOM tree in logical order
+ */
+public class SimpleDOMBuilder {
+	private Document dom=null;
+	private Element currentElement=null;
+	
+	/**
+	 * Append an element to the current element and set this new element to be the current element.
+	 * If there is no current element, a new DOM tree will be created (discarding the current DOM tree if any)
+	 * with the new element as the document element.
+	 * 
+	 * @param sTagName
+	 * @return true on success
+	 */
+	public boolean startElement(String sTagName) {
+		if (currentElement!=null) {
+			currentElement = (Element) currentElement.appendChild(dom.createElement(sTagName));
+		}
+		else {
+	        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+			try {
+		        DocumentBuilder builder = factory.newDocumentBuilder();
+		        DOMImplementation domImpl = builder.getDOMImplementation();
+		        DocumentType doctype = domImpl.createDocumentType(sTagName, "", ""); 
+		        dom = domImpl.createDocument("",sTagName,doctype);
+		        currentElement = dom.getDocumentElement();
+			} catch (ParserConfigurationException e) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * Set the current element to the parent of the current element
+	 * @return true on success, false if there is no current element to end
+	 */
+	public boolean endElement() {
+		if (currentElement!=null) {
+			if (currentElement!=dom.getDocumentElement()) {
+				currentElement=(Element) currentElement.getParentNode();
+			}
+			else { // Back at document element: Finished populating the DOM tree
+				currentElement=null;
+			}
+			return true;
+		}
+		return false;		
+	}
+	
+	/**
+	 * Set an attribute of the current element
+	 * @param sName
+	 * @param sValue
+	 * @return true on success, false if there is no current element
+	 */
+	public boolean setAttribute(String sName,String sValue) {
+		if (currentElement!=null) {
+			currentElement.setAttribute(sName, sValue);
+			return true;
+		}
+		return false;
+	}
+	
+	/**
+	 * Add characters to the currentElement
+	 * @param sText
+	 * @return true on success, false if there is no current element
+	 */
+	public boolean characters(String sText) {
+		if (currentElement!=null) {
+			currentElement.appendChild(dom.createTextNode(sText));
+			return true;
+		}
+		return false;
+	}
+	
+	/**
+	 * Get the DOM tree
+	 * 
+	 * @return the DOM tree, or null if none has been created
+	 */
+	public Document getDOM() {
+		return dom;
+	}
+}