001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jfreechart/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 * KeyedValues.java
029 * ----------------
030 * (C) Copyright 2002-2008, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes:
036 * --------
037 * 23-Oct-2002 : Version 1 (DG);
038 * 12-Jan-2005 : Updated Javadocs to specify new behaviour when key
039 * is not recognised (DG);
040 * ------------- JFREECHART 1.0.0 ---------------------------------------------
041 * 02-May-2006 : Updated API docs (DG);
042 *
043 */
044
045 package org.jfree.data;
046
047 import java.util.List;
048
049 /**
050 * An ordered list of (key, value) items where the keys are unique and
051 * non-<code>null</code>.
052 *
053 * @see Values
054 * @see DefaultKeyedValues
055 */
056 public interface KeyedValues extends Values {
057
058 /**
059 * Returns the key associated with the item at a given position. Note
060 * that some implementations allow re-ordering of the data items, so the
061 * result may be transient.
062 *
063 * @param index the item index (in the range <code>0</code> to
064 * <code>getItemCount() - 1</code>).
065 *
066 * @return The key (never <code>null</code>).
067 *
068 * @throws IndexOutOfBoundsException if <code>index</code> is not in the
069 * specified range.
070 */
071 public Comparable getKey(int index);
072
073 /**
074 * Returns the index for a given key.
075 *
076 * @param key the key (<code>null</code> not permitted).
077 *
078 * @return The index, or <code>-1</code> if the key is unrecognised.
079 *
080 * @throws IllegalArgumentException if <code>key</code> is
081 * <code>null</code>.
082 */
083 public int getIndex(Comparable key);
084
085 /**
086 * Returns the keys for the values in the collection. Note that you can
087 * access the values in this collection by key or by index. For this
088 * reason, the key order is important - this method should return the keys
089 * in order. The returned list may be unmodifiable.
090 *
091 * @return The keys (never <code>null</code>).
092 */
093 public List getKeys();
094
095 /**
096 * Returns the value for a given key.
097 *
098 * @param key the key.
099 *
100 * @return The value (possibly <code>null</code>).
101 *
102 * @throws UnknownKeyException if the key is not recognised.
103 */
104 public Number getValue(Comparable key);
105
106 }