001/* ========================================================================
002 * JCommon : a free general purpose class library for the Java(tm) platform
003 * ========================================================================
004 *
005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006 * 
007 * Project Info:  http://www.jfree.org/jcommon/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it 
010 * under the terms of the GNU Lesser General Public License as published by 
011 * the Free Software Foundation; either version 2.1 of the License, or 
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but 
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
022 * USA.  
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025 * in the United States and other countries.]
026 * 
027 * --------------------
028 * ListReadHandler.java
029 * --------------------
030 * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
031 *
032 * Original Author:  Thomas Morgner;
033 * Contributor(s):   David Gilbert (for Object Refinery Limited);
034 *
035 * $Id: ListReadHandler.java,v 1.3 2005/10/18 13:33:32 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 12-Nov-2003 : Initial version (TM);
040 *  
041 */
042
043package org.jfree.xml.parser.coretypes;
044
045import java.util.ArrayList;
046import java.util.LinkedList;
047import java.util.List;
048import java.util.Stack;
049import java.util.Vector;
050
051import org.jfree.xml.parser.AbstractXmlReadHandler;
052import org.jfree.xml.parser.XmlReadHandler;
053import org.jfree.xml.parser.XmlReaderException;
054import org.xml.sax.Attributes;
055import org.xml.sax.SAXException;
056
057/**
058 * A SAX handler for reading a list from an XML element.
059 */
060public class ListReadHandler extends AbstractXmlReadHandler {
061
062    /** The list under construction. */
063    private List retval;
064    
065    /** The handlers. */
066    private ArrayList handlers;
067    
068    /** The type of list ('array-list', 'linked-list', 'stack', 'vector'). */
069    private String listType;
070
071    /**
072     * Default constructor.
073     */
074    public ListReadHandler() {
075        super();
076    }
077
078    /**
079     * Start parsing.
080     * 
081     * @param attrs  the attributes.
082     * 
083     * @throws SAXException if there is a parsing error.
084     */
085    protected void startParsing(final Attributes attrs) throws SAXException {
086        this.listType = attrs.getValue("type");
087        if (this.listType == null) {
088            this.listType = "array-list";
089        }
090        this.handlers = new ArrayList();
091    }
092
093    /**
094     * Gets a handler for a child.
095     * 
096     * @param tagName  the tag name.
097     * @param atts  the attributes.
098     * 
099     * @return A handler.
100     * 
101     * @throws XmlReaderException if there is a problem with the reader.
102     * @throws SAXException if there is a parsing error.
103     */
104    protected XmlReadHandler getHandlerForChild(final String tagName, final Attributes atts)
105        throws XmlReaderException, SAXException {
106        final XmlReadHandler handler = getRootHandler().createHandler(Object.class, tagName, atts);
107        this.handlers.add(handler);
108        return handler;
109    }
110
111    /**
112     * Parsing is finished.
113     * 
114     * @throws SAXException if there is a parsing error.
115     * @throws XmlReaderException if there is a problem with the reader.
116     * 
117     */
118    protected void doneParsing() throws SAXException, XmlReaderException {
119        final XmlReadHandler[] handler = (XmlReadHandler[])
120        this.handlers.toArray(new XmlReadHandler[this.handlers.size()]);
121        this.retval = createList(handler.length);
122        for (int i = 0; i < handler.length; i++) {
123            this.retval.add(handler[i].getObject());
124        }
125        this.handlers.clear();
126    }
127
128    /**
129     * Creates a list.
130     * 
131     * @param initialSize  the initial size.
132     * 
133     * @return A new list.
134     */
135    private List createList(final int initialSize) {
136        if (this.listType.equals("stack")) {
137            return new Stack();
138        }
139        if (this.listType.equals("linked-list")) {
140            return new LinkedList();
141        }
142        if (this.listType.equals("vector")) {
143            return new Vector(initialSize);
144        }
145        return new ArrayList(initialSize);
146    }
147
148    /**
149     * Returns the object under construction.
150     * 
151     * @return The list.
152     */
153    public Object getObject() {
154        return this.retval;
155    }
156    
157}