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     * ClassFactoryImpl.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: ClassFactoryImpl.java,v 1.5 2005/11/14 11:00:48 mungady Exp $
036     *
037     * Changes (from 19-Feb-2003)
038     * -------------------------
039     * 19-Feb-2003 : Added standard header and Javadocs (DG);
040     * 29-Apr-2003 : Distilled from the JFreeReport project and moved into JCommon
041     * 29-Jul-2004 : Replaced 'enum' variable name (reserved word in JDK 1.5) (DG);
042     *
043     */
044    
045    package org.jfree.xml.factory.objects;
046    
047    import java.util.HashMap;
048    import java.util.Iterator;
049    
050    import org.jfree.util.Configuration;
051    import org.jfree.util.ClassComparator;
052    /**
053     * An abstract class that implements the {@link ClassFactory} interface.
054     *
055     * @author Thomas Morgner.
056     */
057    public abstract class ClassFactoryImpl implements ClassFactory {
058    
059        /** Storage for the classes. */
060        private HashMap classes;
061        /** A class comparator for searching the super class */
062        private ClassComparator comparator;
063        /** The parser/report configuration */
064        private Configuration config;
065    
066        /**
067         * Creates a new class factory.
068         */
069        public ClassFactoryImpl() {
070            this.classes = new HashMap();
071            this.comparator = new ClassComparator();
072        }
073    
074        /**
075         * Returns the class comparator used to sort the super classes of an object.
076         *
077         * @return the class comparator.
078         */
079        public ClassComparator getComparator() {
080            return this.comparator;
081        }
082    
083        /**
084         * Returns an object-description for a class.
085         *
086         * @param c  the class.
087         *
088         * @return An object description.
089         */
090        public ObjectDescription getDescriptionForClass(final Class c) {
091            final ObjectDescription od = (ObjectDescription) this.classes.get(c);
092            if (od == null) {
093                return null;
094            }
095            return od.getInstance();
096        }
097    
098        /**
099         * Returns the most concrete object-description for the super class of a class.
100         *
101         * @param d  the class.
102         * @param knownSuperClass a known supported superclass or null, if no superclass
103         * is known yet.
104         *
105         * @return The object description.
106         */
107        public ObjectDescription getSuperClassObjectDescription
108            (final Class d, ObjectDescription knownSuperClass) {
109            final Iterator iterator = this.classes.keySet().iterator();
110            while (iterator.hasNext()) {
111                final Class keyClass = (Class) iterator.next();
112                if (keyClass.isAssignableFrom(d)) {
113                    final ObjectDescription od = (ObjectDescription) this.classes.get(keyClass);
114                    if (knownSuperClass == null) {
115                        knownSuperClass = od;
116                    }
117                    else {
118                        if (this.comparator.isComparable
119                            (knownSuperClass.getObjectClass(), od.getObjectClass())) {
120                            if (this.comparator.compare
121                                (knownSuperClass.getObjectClass(), od.getObjectClass()) < 0) {
122                                knownSuperClass = od;
123                            }
124                        }
125                    }
126                }
127            }
128            if (knownSuperClass == null) {
129                return null;
130            }
131            return knownSuperClass.getInstance();
132        }
133    
134        /**
135         * Registers an object description with the factory.
136         *
137         * @param key  the key.
138         * @param od  the object description.
139         */
140        protected void registerClass(final Class key, final ObjectDescription od) {
141            this.classes.put(key, od);
142            if (this.config != null) {
143                od.configure(this.config);
144            }
145        }
146    
147        /**
148         * Returns an iterator that provides access to the registered object definitions.
149         *
150         * @return The iterator.
151         */
152        public Iterator getRegisteredClasses() {
153            return this.classes.keySet().iterator();
154        }
155    
156    
157        /**
158         * Configures this factory. The configuration contains several keys and
159         * their defined values. The given reference to the configuration object
160         * will remain valid until the report parsing or writing ends.
161         * <p>
162         * The configuration contents may change during the reporting.
163         *
164         * @param config the configuration, never null
165         */
166        public void configure(final Configuration config) {
167            if (config == null) {
168                throw new NullPointerException("The given configuration is null");
169            }
170            if (this.config != null) {
171                // already configured ... ignored
172                return;
173            }
174    
175            this.config = config;
176            final Iterator it = this.classes.values().iterator();
177            while (it.hasNext()) {
178                final ObjectDescription od = (ObjectDescription) it.next();
179                od.configure(config);
180            }
181        }
182    
183        /**
184         * Returns the currently set configuration or null, if none was set.
185         *
186         * @return the configuration.
187         */
188        public Configuration getConfig() {
189            return this.config;
190        }
191    
192        /**
193         * Tests for equality.
194         * 
195         * @param o  the object to test.
196         * 
197         * @return A boolean.
198         */
199        public boolean equals(final Object o) {
200            if (this == o) {
201                return true;
202            }
203            if (!(o instanceof ClassFactoryImpl)) {
204                return false;
205            }
206    
207            final ClassFactoryImpl classFactory = (ClassFactoryImpl) o;
208    
209            if (!this.classes.equals(classFactory.classes)) {
210                return false;
211            }
212    
213            return true;
214        }
215    
216        /**
217         * Returns a hash code.
218         * 
219         * @return A hash code.
220         */
221        public int hashCode() {
222            return this.classes.hashCode();
223        }
224    }