package org.djunits.unit;
   
   import static org.djunits.unit.unitsystem.UnitSystem.IMPERIAL;
   import static org.djunits.unit.unitsystem.UnitSystem.MTS;
   import static org.djunits.unit.unitsystem.UnitSystem.SI_ACCEPTED;
   import static org.djunits.unit.unitsystem.UnitSystem.SI_BASE;
   import static org.djunits.unit.unitsystem.UnitSystem.US_CUSTOMARY;
   
   import org.djunits.unit.unitsystem.UnitSystem;
  
  /**
   * Standard mass units. Several conversion factors have been taken from <a
   * href="http://en.wikipedia.org/wiki/Conversion_of_units">http://en.wikipedia.org/wiki/Conversion_of_units</a>.
   * <p>
   * Copyright (c) 2015 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="http://djunits.org/docs/license.html">DJUNITS License</a>.
   * <p>
   * $LastChangedDate: 2015-10-04 20:48:33 +0200 (Sun, 04 Oct 2015) $, @version $Revision: 87 $, by $Author: averbraeck $, initial
   * version May 15, 2014 <br>
   * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   */
  public class MassUnit extends Unit<MassUnit>
  {
      /** */
      private static final long serialVersionUID = 20140607L;
  
      /** The SI unit for mass is kilogram. */
      public static final MassUnit SI;
  
      /** kilogram. */
      public static final MassUnit KILOGRAM;
  
      /** gram. */
      public static final MassUnit GRAM;
  
      /** pound. */
      public static final MassUnit POUND;
  
      /** pound. */
      public static final MassUnit OUNCE;
  
      /** long ton = 2240 lb. */
      public static final MassUnit TON_LONG;
  
      /** short ton = 2000 lb. */
      public static final MassUnit TON_SHORT;
  
      /** metric ton = 1000 kg. */
      public static final MassUnit TON_METRIC;
  
      /** metric ton = 1000 kg. */
      public static final MassUnit TONNE;
  
      /** dalton. */
      public static final MassUnit DALTON;
  
      static
      {
          SI = new MassUnit("MassUnit.kilogram", "MassUnit.kg", SI_BASE);
          KILOGRAM = SI;
          GRAM = new MassUnit("MassUnit.gram", "MassUnit.g", SI_BASE, KILOGRAM, 0.001, true);
          POUND = new MassUnit("MassUnit.pound", "MassUnit.lb", IMPERIAL, KILOGRAM, 0.45359237, true);
          OUNCE = new MassUnit("MassUnit.ounce", "MassUnit.oz", IMPERIAL, POUND, 1.0 / 16.0, true);
          TON_LONG = new MassUnit("MassUnit.long_ton", "MassUnit.long_tn", IMPERIAL, POUND, 2240.0, true);
          TON_SHORT = new MassUnit("MassUnit.short_ton", "MassUnit.sh_tn", US_CUSTOMARY, POUND, 2000.0, true);
          TON_METRIC = new MassUnit("MassUnit.metric_ton", "MassUnit.t", SI_ACCEPTED, KILOGRAM, 1000.0, true);
          TONNE = new MassUnit("MassUnit.tonne_(mts)", "MassUnit.t_(mts)", MTS, KILOGRAM, 1000.0, true);
          DALTON = new MassUnit("MassUnit.dalton", "MassUnit.Da", SI_ACCEPTED, KILOGRAM, 1.6605388628E-27, true);
      }
  
      /**
       * Build a standard MassUnit.
       * @param nameKey the key to the locale file for the long name of the unit
       * @param abbreviationKey the key to the locale file for the abbreviation of the unit
       * @param unitSystem the unit system, e.g. SI or Imperial
       */
      private MassUnit(final String nameKey, final String abbreviationKey, final UnitSystem unitSystem)
      {
          super(nameKey, abbreviationKey, unitSystem, true);
      }
  
      /**
       * Build a MassUnit with a conversion factor to another MassUnit.
       * @param nameOrNameKey if standardUnit: the key to the locale file for the long name of the unit, otherwise the name itself
       * @param abbreviationOrAbbreviationKey if standardUnit: the key to the locale file for the abbreviation of the unit,
       *            otherwise the abbreviation itself
       * @param unitSystem the unit system, e.g. SI or Imperial
       * @param referenceUnit the unit to convert to
       * @param conversionFactorToReferenceUnit multiply a value in this unit by the factor to convert to the given reference unit
       * @param standardUnit indicates whether it is a standard unit with a definition in the locale, or a user-defined unit
       */
      private MassUnit(final String nameOrNameKey, final String abbreviationOrAbbreviationKey,
          final UnitSystem unitSystem, final MassUnit referenceUnit, final double conversionFactorToReferenceUnit,
          final boolean standardUnit)
      {
          super(nameOrNameKey, abbreviationOrAbbreviationKey, unitSystem, referenceUnit, conversionFactorToReferenceUnit,
              standardUnit);
      }
  
     /**
      * Build a user-defined MassUnit with a conversion factor to another MassUnit.
      * @param name the long name of the unit
      * @param abbreviation the abbreviation of the unit
      * @param unitSystem the unit system, e.g. SI or Imperial
      * @param referenceUnit the unit to convert to
      * @param conversionFactorToReferenceUnit multiply a value in this unit by the factor to convert to the given reference unit
      */
     public MassUnit(final String name, final String abbreviation, final UnitSystem unitSystem,
         final MassUnit referenceUnit, final double conversionFactorToReferenceUnit)
     {
         this(name, abbreviation, unitSystem, referenceUnit, conversionFactorToReferenceUnit, false);
     }
 
     /** {@inheritDoc} */
     @Override
     public final MassUnit getStandardUnit()
     {
         return KILOGRAM;
     }
 
     /** {@inheritDoc} */
     @Override
     public final String getSICoefficientsString()
     {
         return "kg";
     }
 
 }