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 * ObjectDescription.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: ObjectDescription.java,v 1.3 2005/11/14 11:03:12 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 *
042 */
043
044 package org.jfree.xml.factory.objects;
045
046 import java.io.Serializable;
047 import java.util.Iterator;
048
049 import org.jfree.util.Configuration;
050
051 /**
052 * An interface for object descriptions.
053 *
054 * @author Thomas Morgner
055 */
056 public interface ObjectDescription extends Serializable {
057
058 /**
059 * Returns a parameter definition. If the parameter is invalid, this
060 * function returns null.
061 *
062 * @param name the definition name.
063 *
064 * @return The parameter class or null, if the parameter is not defined.
065 */
066 public Class getParameterDefinition(String name);
067
068 /**
069 * Sets the value of a parameter.
070 *
071 * @param name the parameter name.
072 * @param value the parameter value.
073 */
074 public void setParameter(String name, Object value);
075
076 /**
077 * Returns the value of a parameter.
078 *
079 * @param name the parameter name.
080 *
081 * @return The value.
082 */
083 public Object getParameter(String name);
084
085 /**
086 * Returns an iterator the provides access to the parameter names. This
087 * returns all _known_ parameter names, the object description may accept
088 * additional parameters.
089 *
090 * @return The iterator.
091 */
092 public Iterator getParameterNames();
093
094 /**
095 * Returns the object class.
096 *
097 * @return The Class.
098 */
099 public Class getObjectClass();
100
101 /**
102 * Creates an object based on the description.
103 *
104 * @return The object.
105 */
106 public Object createObject();
107
108 /**
109 * Returns a cloned instance of the object description. The contents
110 * of the parameter objects collection are cloned too, so that any
111 * already defined parameter value is copied to the new instance.
112 * <p>
113 * Parameter definitions are not cloned, as they are considered read-only.
114 * <p>
115 * The newly instantiated object description is not configured. If it
116 * need to be configured, then you have to call configure on it.
117 *
118 * @return A cloned instance.
119 */
120 public ObjectDescription getUnconfiguredInstance();
121
122 /**
123 * Returns a cloned instance of the object description. The contents
124 * of the parameter objects collection are cloned too, so that any
125 * already defined parameter value is copied to the new instance.
126 * <p>
127 * Parameter definitions are not cloned, as they are considered read-only.
128 *
129 * @return A cloned instance.
130 */
131 public ObjectDescription getInstance();
132
133 /**
134 * Sets the parameters of this description object to match the supplied object.
135 *
136 * @param o the object.
137 *
138 * @throws ObjectFactoryException if there is a problem while reading the
139 * properties of the given object.
140 */
141 public void setParameterFromObject(Object o) throws ObjectFactoryException;
142
143
144 /**
145 * Configures this factory. The configuration contains several keys and
146 * their defined values. The given reference to the configuration object
147 * will remain valid until the report parsing or writing ends.
148 * <p>
149 * The configuration contents may change during the reporting.
150 *
151 * @param config the configuration, never null
152 */
153 public void configure(Configuration config);
154
155 /**
156 * Compares whether two object descriptions are equal.
157 *
158 * @param o the other object.
159 * @return true, if both object desciptions describe the same object, false otherwise.
160 */
161 public boolean equals (Object o);
162
163
164 /**
165 * Computes the hashCode for this ClassFactory. As equals() must be implemented,
166 * a corresponding hashCode() should be implemented as well.
167 *
168 * @return the hashcode.
169 */
170 public int hashCode();
171
172 }