001 /* AttributeSet.java --
002 Copyright (C) 2002, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
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007 it under the terms of the GNU General Public License as published by
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019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
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034 this exception to your version of the library, but you are not
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036 exception statement from your version. */
037
038 package javax.print.attribute;
039
040 /**
041 * <code>AttributeSet</code> is the top-level interface for sets of printing
042 * attributes in the Java Print Service API.
043 * <p>
044 * There are no duplicate values allowed in an attribute set and there is
045 * at most one attribute object contained per category type. Based on the
046 * {@link java.util.Map} interface the values of attribute sets are objects
047 * of type {@link javax.print.attribute.Attribute} and the entries are the
048 * categories as {@link java.lang.Class} instances.
049 * </p>
050 * <p>
051 * The following specialized types of <code>AttributeSet</code> are available:
052 * <ul>
053 * <li>{@link javax.print.attribute.DocAttributeSet}</li>
054 * <li>{@link javax.print.attribute.PrintRequestAttributeSet}</li>
055 * <li>{@link javax.print.attribute.PrintJobAttributeSet}</li>
056 * <li>{@link javax.print.attribute.PrintServiceAttributeSet}</li>
057 * </ul>
058 * </p>
059 * <p>
060 * Attribute sets may be unmodifiable depending on the context of usage. If
061 * used as read-only attribute set modifying operations throw an
062 * {@link javax.print.attribute.UnmodifiableSetException}.
063 * </p>
064 * <p>
065 * The Java Print Service API provides implementation classes for the existing
066 * attribute set interfaces but applications may use their own implementations.
067 * </p>
068 *
069 * @author Michael Koch (konqueror@gmx.de)
070 */
071 public interface AttributeSet
072 {
073 /**
074 * Adds the specified attribute value to this attribute set
075 * if it is not already present.
076 *
077 * This operation removes any existing attribute of the same category
078 * before adding the given attribute to the set.
079 *
080 * @param attribute the attribute to add.
081 * @return <code>true</code> if the set is changed, false otherwise.
082 * @throws NullPointerException if the attribute is <code>null</code>.
083 * @throws UnmodifiableSetException if the set does not support modification.
084 */
085 boolean add (Attribute attribute);
086
087 /**
088 * Adds all of the elements in the specified set to this attribute set.
089 *
090 * @param attributes the set of attributes to add.
091 * @return <code>true</code> if the set is changed, false otherwise.
092 * @throws UnmodifiableSetException if the set does not support modification.
093 *
094 * @see #add(Attribute)
095 */
096 boolean addAll (AttributeSet attributes);
097
098 /**
099 * Removes all attributes from this attribute set.
100 *
101 * @throws UnmodifiableSetException if the set does not support modification.
102 */
103 void clear ();
104
105 /**
106 * Checks if this attributes set contains an attribute with the given
107 * category.
108 *
109 * @param category the category to test for.
110 * @return <code>true</code> if an attribute of the category is contained
111 * in the set, <code>false</code> otherwise.
112 */
113 boolean containsKey (Class<?> category);
114
115 /**
116 * Checks if this attribute set contains the given attribute.
117 *
118 * @param attribute the attribute to test for.
119 * @return <code>true</code> if the attribute is contained in the set,
120 * <code>false</code> otherwise.
121 */
122 boolean containsValue (Attribute attribute);
123
124 /**
125 * Tests this set for equality with the given object. <code>true</code> is
126 * returned, if the given object is also of type <code>AttributeSet</code>
127 * and the contained attributes are the same as in this set.
128 *
129 * @param obj the Object to test.
130 * @return <code>true</code> if equal, false otherwise.
131 */
132 boolean equals (Object obj);
133
134 /**
135 * Returns the attribute object contained in this set for the given attribute
136 * category.
137 *
138 * @param category the category of the attribute. A <code>Class</code>
139 * instance of a class implementing the <code>Attribute</code> interface.
140 * @return The attribute for this category or <code>null</code> if no
141 * attribute is contained for the given category.
142 * @throws NullPointerException if category is null.
143 * @throws ClassCastException if category is not implementing
144 * <code>Attribute</code>.
145 */
146 Attribute get (Class<?> category);
147
148 /**
149 * Returns the hashcode value. The hashcode value is the sum of all hashcodes
150 * of the attributes contained in this set.
151 *
152 * @return The hashcode for this attribute set.
153 */
154 int hashCode ();
155
156 /**
157 * Checks if the attribute set is empty.
158 *
159 * @return <code>true</code> if the attribute set is empty, false otherwise.
160 */
161 boolean isEmpty ();
162
163 /**
164 * Removes the given attribute from the set. If the given attribute is <code>null</code>
165 * nothing is done and <code>false</code> is returned.
166 *
167 * @param attribute the attribute to remove.
168 * @return <code>true</code> if removed, false in all other cases.
169 * @throws UnmodifiableSetException if the set does not support modification.
170 */
171 boolean remove (Attribute attribute);
172
173 /**
174 * Removes the attribute entry of the given category from the set. If the given
175 * category is <code>null</code> nothing is done and <code>false</code> is returned.
176 *
177 * @param category the category of the entry to be removed.
178 * @return <code>true</code> if an attribute is removed, false in all other cases.
179 * @throws UnmodifiableSetException if the set does not support modification.
180 */
181 boolean remove (Class<?> category);
182
183 /**
184 * Returns the number of elements in this attribute set.
185 *
186 * @return The number of elements.
187 */
188 int size ();
189
190 /**
191 * Returns the content of the attribute set as an array
192 *
193 * @return An array of attributes.
194 */
195 Attribute[] toArray ();
196 }