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 * ArrayObjectDescription.java
029 * ---------------------------
030 * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
031 *
032 * Original Author:  Thomas Morgner (taquera@sherito.org);
033 * Contributor(s):   David Gilbert (for Object Refinery Limited);
034 *
035 * $Id: ArrayObjectDescription.java,v 1.4 2006/01/27 18:53:15 taqua Exp $
036 *
037 * Changes
038 * -------
039 * 14-Apr-2003 : Initial version
040 * 29-Apr-2003 : Distilled from the JFreeReport project and moved into JCommon
041 */
042package org.jfree.xml.factory.objects;
043
044import java.lang.reflect.Array;
045import java.util.ArrayList;
046import java.util.Iterator;
047
048import org.jfree.util.Log;
049
050/**
051 * Describes an Object- or primitive value array. This object description is
052 * not intended to be created outside the ArrayClassFactory.
053 *
054 * @author Thomas Morgner
055 */
056public class ArrayObjectDescription extends AbstractObjectDescription {
057
058    /**
059     * Constructs a new array objet description for the given array class.
060     * <P>
061     * Note:  throws <code>IllegalArgumentException</code> if the given class is no array.
062     * 
063     * @param c the array class object.
064     */
065    public ArrayObjectDescription(final Class c) {
066        super(c);
067        if (!c.isArray()) {
068            throw new IllegalArgumentException("Need an array class");
069        }
070    }
071
072    /**
073     * Creates an object based on the description.
074     *
075     * @return The object.
076     */
077    public Object createObject() {
078        try {
079            final Integer size = (Integer) getParameter("size");
080            if (size == null) {
081                final ArrayList l = new ArrayList();
082                int counter = 0;
083                while (getParameterDefinition(String.valueOf(counter)) != null) {
084                    final Object value = getParameter(String.valueOf(counter));
085                    if (value == null) {
086                        break;
087                    }
088
089                    l.add(value);
090                    counter += 1;
091                }
092
093                final Object o = Array.newInstance
094                    (getObjectClass().getComponentType(), l.size());
095                for (int i = 0; i < l.size(); i++) {
096                    Array.set(o, i, l.get(i));
097                }
098                return o;
099            }
100            else {
101                // a size is given, so we can assume that all values are defined.
102                final Object o = Array.newInstance
103                    (getObjectClass().getComponentType(), size.intValue());
104                for (int i = 0; i < size.intValue(); i++) {
105                    Array.set(o, i, getParameter(String.valueOf(i)));
106                }
107                return o;
108            }
109        }
110        catch (Exception ie) {
111            Log.warn("Unable to instantiate Object", ie);
112            return null;
113        }
114    }
115
116    /**
117     * Sets the parameters of this description object to match the supplied object.
118     *
119     * @param o  the object.
120     *
121     * @throws ObjectFactoryException if there is a
122     * problem while reading the properties of the given object.
123     */
124    public void setParameterFromObject(final Object o) throws ObjectFactoryException {
125        if (o == null) {
126            throw new ObjectFactoryException("Given object is null.");
127        }
128
129        if (!o.getClass().isArray()) {
130            throw new ObjectFactoryException("Given object is no array");
131        }
132
133        if (!getObjectClass().isAssignableFrom(o.getClass())) {
134            throw new ObjectFactoryException("Given object is incompatible with base class");
135        }
136
137        final int size = Array.getLength(o);
138        setParameter("size", new Integer(size));
139        for (int i = 0; i < size; i++) {
140            setParameter(String.valueOf(i), Array.get(o, i));
141        }
142    }
143
144    /**
145     * Tries to parse the given parameter string into a positive integer.
146     * Returns -1 if the parsing failed for some reason.
147     *
148     * @param name the name of the parameter.
149     * @return the parsed int value or -1 on errors.
150     */
151    private int parseParameterName(final String name) {
152        try {
153            return Integer.parseInt(name);
154        }
155        catch (Exception e) {
156            return -1;
157        }
158    }
159
160    /**
161     * Returns a parameter definition. If the parameter is invalid, this
162     * function returns null.
163     *
164     * @param name  the definition name.
165     *
166     * @return The parameter class or null, if the parameter is not defined.
167     */
168    public Class getParameterDefinition(final String name) {
169        if (name.equals("size")) {
170            return Integer.TYPE;
171        }
172        final int par = parseParameterName(name);
173        if (par < 0) {
174            return null;
175        }
176        return getObjectClass().getComponentType();
177    }
178
179    /**
180     * Returns an iterator for the parameter names.
181     *
182     * @return The iterator.
183     */
184    public Iterator getParameterNames() {
185        final Integer size = (Integer) getParameter("size");
186        if (size == null) {
187            return getDefinedParameterNames();
188        }
189        else {
190            final ArrayList l = new ArrayList();
191            l.add("size");
192            for (int i = 0; i < size.intValue(); i++) {
193                l.add(String.valueOf(i));
194            }
195            return l.iterator();
196        }
197    }
198
199    /**
200     * Returns a new instance of the object description.
201     *
202     * @return The object description.
203     */
204    public ObjectDescription getInstance() {
205        return new ArrayObjectDescription(getObjectClass());
206    }
207}