001    /* AttributeSet.java --
002       Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package javax.swing.text;
039    
040    import java.util.Enumeration;
041    
042    /**
043     * A set of attributes. An attribute has a key and a value. They typically
044     * describe features of a piece of text that make up its graphical
045     * representation.
046     *
047     * An <code>AttributeSet</code> may have a resolving parent,
048     * that is another <code>AttributeSet</code> that is searched for attribute
049     * keys that are not stored locally in this <code>AttributeSet</code>.
050     *
051     * @author original author unknown
052     * @author Roman Kennke (roman@kennke.org)
053     */
054    public interface AttributeSet
055    {
056      /**
057       * Used as keys to identify character-run attributes.
058       */
059      static interface CharacterAttribute
060      {
061        // This interface is a marker interface and has no methods.
062      }
063    
064      /**
065       * Used as keys to identify color attributes.
066       */
067      static interface ColorAttribute
068      {
069        // This interface is a marker interface and has no methods.
070      }
071    
072      /**
073       * Used as keys to identify font attributes.
074       */
075      static interface FontAttribute
076      {
077        // This interface is a marker interface and has no methods.
078      }
079    
080      /**
081       * Used as keys to identify paragraph level attributes.
082       */
083      static interface ParagraphAttribute
084      {
085        // This interface is a marker interface and has no methods.
086      }
087    
088      /**
089       * Key of the attribute that is used to describe the name of an
090       * <code>AttributeSet</code>.
091       */
092      Object NameAttribute = StyleConstants.NameAttribute;
093    
094      /**
095       * Key of the attribute that is used to identify the resolving parent of
096       * an <code>AttributeSet</code>.
097       */
098      Object ResolveAttribute = StyleConstants.ResolveAttribute;
099    
100      /**
101       * Returns <code>true</code> if this <code>AttributeSet</code> contains
102       * an attribute with the specified <code>name</code> and <code>value</code>,
103       * <code>false</code> otherwise.
104       *
105       * @param name the name of the requested attribute
106       * @param value the value of the requested attribute
107       *
108       * @return <code>true</code> if this <code>AttributeSet</code> contains
109       *         an attribute with the specified <code>name</code> and
110       *         <code>value</code>, <code>false</code> otherwise
111       */
112      boolean containsAttribute(Object name, Object value);
113    
114      /**
115       * Returns <code>true</code> of this <code>AttributeSet</code> contains all
116       * of the specified <code>attributes</code>.
117       *
118       * @param attributes the requested attributes
119       *
120       * @return <code>true</code> of this <code>AttributeSet</code> contains all
121       *         of the specified <code>attributes</code>
122       */
123      boolean containsAttributes(AttributeSet attributes);
124    
125      /**
126       * Creates and returns a copy of this <code>AttributeSet</code>.
127       *
128       * @return a copy of this <code>AttributeSet</code>
129       */
130      AttributeSet copyAttributes();
131    
132      /**
133       * Returns the attribute with the specified <code>key</code> or
134       * <code>null</code> if no such attribute is defined in this
135       * <code>AttributeSet</code> and its resolving parents.
136       *
137       * @param key the key of the attribute that is looked up
138       *
139       * @return the attribute with the specified <code>key</code> or
140       *         <code>null</code> if no such attribute is defined in this
141       *         <code>AttributeSet</code> and its resolving parents
142       */
143      Object getAttribute(Object key);
144    
145      /**
146       * Returns the number of attributes that are stored locally in this
147       * <code>AttributeSet</code>.
148       *
149       * @return the number of attributes that are stored locally in this
150       * <code>AttributeSet</code>
151       */
152      int getAttributeCount();
153    
154      /**
155       * Returns the names of the attributes that are stored in this
156       * <code>AttributeSet</code>.
157       *
158       * @return the names of the attributes that are stored in this
159       *         <code>AttributeSet</code>
160       */
161      Enumeration<?> getAttributeNames();
162    
163      /**
164       * Returns the resolving parent of this <code>AttributeSet</code>.
165       * If a key is not stored locally, then a {@link #getAttribute(Object)}
166       * request is resolved up in the resolving parent of this
167       * <code>AttributeSet</code>.
168       *
169       * @return the resolving parent of this <code>AttributeSet</code>
170       */
171      AttributeSet getResolveParent();
172    
173      /**
174       * Returns <code>true</code> if an attribute with the specified name is
175       * defined locally in this <code>AttributeSet</code>, without resolving
176       * through the resolving parents.
177       *
178       * @return <code>true</code> if an attribute with the specified name is
179       *          defined locally in this <code>AttributeSet</code>
180       */
181      boolean isDefined(Object attrName);
182    
183      /**
184       * Returns <code>true</code> if all of the attributes in <code>attr</code>
185       * are equal to the attributes in this <code>AttributeSet</code>,
186       * <code>false</code> otherwise.
187       *
188       * @param attr the attributes to be compared to <code>this</code>
189       *
190       * @return <code>true</code> if all of the attributes in <code>attr</code>
191       *         are equal to the attributes in this <code>AttributeSet</code>,
192       *         <code>false</code> otherwise
193       */
194      boolean isEqual(AttributeSet attr);
195    }