001/* ===========================================================
002 * Orson Charts : a 3D chart library for the Java(tm) platform
003 * ===========================================================
004 * 
005 * (C)opyright 2013-2016, by Object Refinery Limited.  All rights reserved.
006 * 
007 * http://www.object-refinery.com/orsoncharts/index.html
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 com.orsoncharts.data;
034
035/**
036 * A generic representation of a one dimensional list of data values.
037 */
038public interface Values<T> {
039    
040    /**
041     * Returns the number of items in the dataset.
042     *
043     * @return The number of items in the dataset.
044     */
045    int getItemCount();
046
047    /**
048     * Returns the value for the specified item.
049     *
050     * @param item  the item index.
051     *
052     * @return The value for the specified item (possibly {@code null}).
053     */
054    T getValue(int item);
055  
056    /**
057     * Returns the value for the specified item as a double primitive, provided
058     * that the data type is a subclass of {@code Number}.  Where
059     * the {@link #getValue(int)} method returns {@code null}, this method
060     * returns {@code Double.NaN}.
061     * 
062     * @param item  the item index.
063     * 
064     * @return The value for the specified item. 
065     */
066    double getDoubleValue(int item);
067
068}