001    package edu.nrao.sss.model.resource.vla;
002    
003    import java.util.ArrayList;
004    import java.util.List;
005    
006    /**
007     * VLA intermediate frequencies that are typically associated together.
008     * The names of the IFs are "A", "B", "C", and "D".
009     * These are often paired into "AC" and "BD".
010     * <p>
011     * <b>Version Info:</b>
012     * <table style="margin-left:2em">
013     *   <tr><td>$Revision: 1222 $</td></tr>
014     *   <tr><td>$Date: 2008-04-15 11:16:50 -0600 (Tue, 15 Apr 2008) $</td></tr>
015     *   <tr><td>$Author: dharland $ (last person to modify)</td></tr>
016     * </table></p>
017     * 
018     * @author David M. Harland
019     * @since 2008-03-19
020     */
021    public enum IFPair
022    {
023      AC
024      {
025        List<IFCode> getIfCodes()
026        {
027          List<IFCode> codes = new ArrayList<IFCode>();
028          codes.add(IFCode.A); codes.add(IFCode.C);
029          return codes;
030        }
031      },
032      BD
033      {
034        List<IFCode> getIfCodes()
035        {
036          List<IFCode> codes = new ArrayList<IFCode>();
037          codes.add(IFCode.B); codes.add(IFCode.D);
038          return codes;
039        }
040      };
041      
042      abstract List<IFCode> getIfCodes();
043    }