Values.java

/* ===========================================================
 * Orson Charts : a 3D chart library for the Java(tm) platform
 * ===========================================================
 * 
 * (C)opyright 2013-2016, by Object Refinery Limited.  All rights reserved.
 * 
 * http://www.object-refinery.com/orsoncharts/index.html
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
 * Other names may be trademarks of their respective owners.]
 * 
 * If you do not wish to be bound by the terms of the GPL, an alternative
 * commercial license can be purchased.  For details, please see visit the
 * Orson Charts home page:
 * 
 * http://www.object-refinery.com/orsoncharts/index.html
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 */

package com.orsoncharts.data;

/**
 * A generic representation of a one dimensional list of data values.
 */
public interface Values<T> {
    
    /**
     * Returns the number of items in the dataset.
     *
     * @return The number of items in the dataset.
     */
    int getItemCount();

    /**
     * Returns the value for the specified item.
     *
     * @param item  the item index.
     *
     * @return The value for the specified item (possibly {@code null}).
     */
    T getValue(int item);
  
    /**
     * Returns the value for the specified item as a double primitive, provided
     * that the data type is a subclass of {@code Number}.  Where
     * the {@link #getValue(int)} method returns {@code null}, this method
     * returns {@code Double.NaN}.
     * 
     * @param item  the item index.
     * 
     * @return The value for the specified item. 
     */
    double getDoubleValue(int item);

}