001/* AttributeSet.java -- 002 Copyright (C) 2002, 2005 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package 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 */ 071public 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}