001/*
002 * Units of Measurement Implementation for Java SE
003 * Copyright (c) 2005-2017, Jean-Marie Dautelle, Werner Keil, V2COM.
004 *
005 * All rights reserved.
006 *
007 * Redistribution and use in source and binary forms, with or without modification,
008 * are permitted provided that the following conditions are met:
009 *
010 * 1. Redistributions of source code must retain the above copyright notice,
011 *    this list of conditions and the following disclaimer.
012 *
013 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
014 *    and the following disclaimer in the documentation and/or other materials provided with the distribution.
015 *
016 * 3. Neither the name of JSR-363 nor the names of its contributors may be used to endorse or promote products
017 *    derived from this software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
020 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
021 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
022 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
023 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
026 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
028 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package tec.uom.se.unit;
031
032import java.util.Map;
033import java.util.Objects;
034
035import javax.measure.Dimension;
036import javax.measure.Quantity;
037import javax.measure.Unit;
038import javax.measure.UnitConverter;
039
040import tec.uom.lib.common.function.UnitConverterSupplier;
041import tec.uom.se.AbstractUnit;
042
043/**
044 * <p>
045 * This class represents the units derived from other units using {@linkplain UnitConverter converters}.
046 * </p>
047 *
048 * <p>
049 * Examples of transformed units:<code>
050 *         CELSIUS = KELVIN.shift(273.15);
051 *         FOOT = METRE.multiply(3048).divide(10000);
052 *         MILLISECOND = MILLI(SECOND);
053 *     </code>
054 * </p>
055 *
056 * <p>
057 * Transformed units have no symbol. But like any other units, they may have labels attached to them (see
058 * {@link javax.measure.format.UnitFormat#label(Unit, String) UnitFormat.label}
059 * </p>
060 *
061 * <p>
062 * Instances of this class are created through the {@link AbstractUnit#transform} method.
063 * </p>
064 *
065 * @param <Q>
066 *          The type of the quantity measured by this unit.
067 *
068 * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a>
069 * @author <a href="mailto:units@catmedia.us">Werner Keil</a>
070 * @version 0.7, December 28, 2015
071 */
072public final class TransformedUnit<Q extends Quantity<Q>> extends AbstractUnit<Q> implements UnitConverterSupplier {
073
074  /**
075         *
076         */
077  private static final long serialVersionUID = 1L;
078
079  /**
080   * Holds the parent unit (always a system unit).
081   */
082  private final AbstractUnit<Q> parentUnit;
083
084  /**
085   * Holds the converter to the parent unit.
086   */
087  private final UnitConverter converter;
088
089  /**
090   * Holds the symbol.
091   */
092  private String symbol;
093
094  /**
095   * Creates a transformed unit from the specified system unit. using the parent as symbol
096   * 
097   * @param parentUnit
098   *          the system unit from which this unit is derived.
099   * @param converter
100   *          the converter to the parent units.
101   * @throws IllegalArgumentException
102   *           if the specified parent unit is not an {@link AbstractUnit#isSystemUnit() system unit}
103   */
104  public TransformedUnit(Unit<Q> parentUnit, UnitConverter unitConverter) {
105    this(parentUnit.getSymbol(), parentUnit, unitConverter);
106  }
107
108  public TransformedUnit(String symbol, Unit<Q> parentUnit, UnitConverter unitConverter) {
109    if (parentUnit instanceof AbstractUnit) {
110      final AbstractUnit<Q> abParent = (AbstractUnit<Q>) parentUnit;
111      if (!abParent.isSystemUnit()) {
112        throw new IllegalArgumentException("The parent unit: " + abParent + " is not a system unit");
113      }
114      this.parentUnit = abParent;
115      this.converter = unitConverter;
116      this.symbol = symbol;
117      // this.symbol = symbol; //TODO see
118      // https://github.com/unitsofmeasurement/uom-se/issues/54
119    } else {
120      throw new IllegalArgumentException("The parent unit: " + parentUnit + " is not an abstract unit.");
121    }
122  }
123
124  @Override
125  public Dimension getDimension() {
126    return parentUnit.getDimension();
127  }
128
129  @Override
130  public UnitConverter getSystemConverter() {
131    return parentUnit.getSystemConverter().concatenate(converter);
132  }
133
134  @Override
135  public UnitConverter getConverter() {
136    return converter;
137  }
138
139  @Override
140  public AbstractUnit<Q> toSystemUnit() {
141    return parentUnit.getSystemUnit();
142  }
143
144  @Override
145  public Map<? extends Unit<?>, Integer> getBaseUnits() {
146    return parentUnit.getBaseUnits();
147  }
148
149  @Override
150  public int hashCode() {
151    return Objects.hash(parentUnit, converter);
152  }
153
154  @Override
155  public boolean equals(Object obj) {
156    if (this == obj) {
157      return true;
158    }
159    if (obj instanceof TransformedUnit) {
160      TransformedUnit<?> other = (TransformedUnit<?>) obj;
161      return Objects.equals(parentUnit, other.parentUnit) && Objects.equals(converter, other.converter);
162    }
163    return false;
164  }
165
166  @Override
167  public String getSymbol() {
168    return symbol;
169  }
170
171  public Unit<Q> getParentUnit() {
172    return parentUnit;
173  }
174}