001    package edu.nrao.sss.sort;
002    
003    /**
004     * Gives direction to {@link SortKey sort keys}.
005     * <p>
006     * <b>Version Info:</b>
007     * <table style="margin-left:2em">
008     *   <tr><td>$Revision: 593 $</td></tr>
009     *   <tr><td>$Date: 2007-05-07 15:54:14 -0600 (Mon, 07 May 2007) $</td></tr>
010     *   <tr><td>$Author: dharland $</td></tr>
011     * </table></p>
012     * 
013     * @author David M. Harland
014     * @since 2007-05-03
015     */
016    public enum SortOrder
017    {
018      /**
019       * An ordering deemed to be natural, usually by the object being sorted.
020       */
021      NATURAL,
022      
023      /** An ordering from lowest to highest. */
024      ASCENDING,
025      
026      /** An ordering from highest to lowest. */
027      DESCENDING,
028      
029      /** An ordering from undisturbed from its current order. */
030      AS_IS,
031      
032      /**
033       * An ordering of custom design.
034       * Note that some objects that have a sort order do not accept
035       * this element.
036       */
037      CUSTOM;
038    }