001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * -----------
028 * Values.java
029 * -----------
030 * (C) Copyright 2001-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.data;
038
039/**
040 * An interface through which (single-dimension) data values can be accessed.
041 */
042public interface Values {
043
044    /**
045     * Returns the number of items (values) in the collection.
046     *
047     * @return The item count (possibly zero).
048     */
049    int getItemCount();
050
051    /**
052     * Returns the value with the specified index.
053     *
054     * @param index  the item index (in the range {@code 0} to
055     *     {@code getItemCount() -1}).
056     *
057     * @return The value (possibly {@code null}).
058     *
059     * @throws IndexOutOfBoundsException if {@code index} is not in the
060     *     specified range.
061     */
062    Number getValue(int index);
063
064}