001/* ===========================================================
002 * Orson Charts : a 3D chart library for the Java(tm) platform
003 * ===========================================================
004 * 
005 * (C)opyright 2013-2022, by David Gilbert.  All rights reserved.
006 * 
007 * https://github.com/jfree/orson-charts
008 * 
009 * This program is free software: you can redistribute it and/or modify
010 * it under the terms of the GNU General Public License as published by
011 * the Free Software Foundation, either version 3 of the License, or
012 * (at your option) any later version.
013 *
014 * This program is distributed in the hope that it will be useful,
015 * but WITHOUT ANY WARRANTY; without even the implied warranty of
016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
017 * GNU General Public License for more details.
018 *
019 * You should have received a copy of the GNU General Public License
020 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
021 * 
022 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
023 * Other names may be trademarks of their respective owners.]
024 * 
025 * If you do not wish to be bound by the terms of the GPL, an alternative
026 * commercial license can be purchased.  For details, please see visit the
027 * Orson Charts home page:
028 * 
029 * http://www.object-refinery.com/orsoncharts/index.html
030 * 
031 */
032
033package org.jfree.chart3d.data;
034
035import java.util.List;
036
037/**
038 * A list of values that are associated with unique keys.
039 * 
040 * @param <K>  the key type (must implement Comparable).
041 * @param <T>  the value type.
042 */
043public interface KeyedValues<K extends Comparable<K>, T> extends Values<T> { 
044
045    /**
046     * Returns the key for the specified item in the list.
047     * 
048     * @param index  the item index.
049     * 
050     * @return The key. 
051     */
052    K getKey(int index);
053  
054    /**
055     * Returns the index for the specified key, or {@code -1} if the key
056     * is not present in the list.
057     * 
058     * @param key  the key ({@code null} not permitted).
059     * 
060     * @return The item index, or {@code -1}. 
061     */
062    int getIndex(K key);
063  
064    /**
065     * Returns a list of all the keys.  Note that the list will be a copy, so
066     * modifying it will not impact this data structure.
067     * 
068     * @return A list of keys (possibly empty, but never {@code null}).
069     */
070    List<K> getKeys();
071
072    /**
073     * Returns the value associated with the specified key, or 
074     * {@code null}.
075     * 
076     * @param key  the key ({@code null} not permitted).
077     * 
078     * @return The value (possibly {@code null}). 
079     */
080    T getValue(K key);
081
082}