001/*
002 * Units of Measurement Reference Implementation
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.units.ri.function;
031
032import javax.measure.UnitConverter;
033
034import tec.units.ri.AbstractConverter;
035import tec.uom.lib.common.function.ValueSupplier;
036
037/**
038 * <p>
039 * This class represents a converter multiplying numeric values by a constant scaling factor (<code>double</code> based).
040 * </p>
041 * 
042 * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a>
043 * @author <a href="mailto:units@catmedia.us">Werner Keil</a>
044 * @version 1.0, October 6, 2016
045 * @since 1.0
046 */
047public final class MultiplyConverter extends AbstractConverter implements ValueSupplier<Double> {
048
049  /**
050         * 
051         */
052  // private static final long serialVersionUID = 6588759878444545649L;
053
054  /**
055   * Holds the scale factor.
056   */
057  private double factor;
058
059  /**
060   * Creates a multiply converter with the specified scale factor.
061   * 
062   * @param factor
063   *          the scaling factor.
064   * @throws IllegalArgumentException
065   *           if coefficient is <code>1.0</code> (would result in identity converter)
066   */
067  public MultiplyConverter(double factor) {
068    if (factor == 1.0)
069      throw new IllegalArgumentException("Would result in identity converter");
070    this.factor = factor;
071  }
072
073  /**
074   * Returns the scale factor of this converter.
075   * 
076   * @return the scale factor.
077   */
078  public double getFactor() {
079    return factor;
080  }
081
082  @Override
083  public UnitConverter concatenate(UnitConverter converter) {
084    if (!(converter instanceof MultiplyConverter))
085      return super.concatenate(converter);
086    double newfactor = factor * ((MultiplyConverter) converter).factor;
087    return newfactor == 1.0 ? IDENTITY : new MultiplyConverter(newfactor);
088  }
089
090  @Override
091  public MultiplyConverter inverse() {
092    return new MultiplyConverter(1.0 / factor);
093  }
094
095  @Override
096  public double convert(double value) {
097    return value * factor;
098  }
099
100  @Override
101  public final String toString() {
102    return "MultiplyConverter(" + factor + ")";
103  }
104
105  @Override
106  public boolean equals(Object obj) {
107    if (!(obj instanceof MultiplyConverter))
108      return false;
109    MultiplyConverter that = (MultiplyConverter) obj;
110    return this.factor == that.factor;
111  }
112
113  @Override
114  public int hashCode() {
115    long bits = Double.doubleToLongBits(factor);
116    return (int) (bits ^ (bits >>> 32));
117  }
118
119  public boolean isLinear() {
120    return true;
121  }
122
123  public Double getValue() {
124    return factor;
125  }
126}