001/*
002 * Units of Measurement Reference Implementation
003 * Copyright (c) 2005-2016, 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 0.4, December 28, 2015
045 */
046public final class MultiplyConverter extends AbstractConverter implements ValueSupplier<Double> {
047
048  /**
049         * 
050         */
051  // private static final long serialVersionUID = 6588759878444545649L;
052
053  /**
054   * Holds the scale factor.
055   */
056  private double factor;
057
058  /**
059   * Creates a multiply converter with the specified scale factor.
060   * 
061   * @param factor
062   *          the scaling factor.
063   * @throws IllegalArgumentException
064   *           if coefficient is <code>1.0</code> (would result in identity converter)
065   */
066  public MultiplyConverter(double factor) {
067    if (factor == 1.0)
068      throw new IllegalArgumentException("Would result in identity converter");
069    this.factor = factor;
070  }
071
072  /**
073   * Returns the scale factor of this converter.
074   * 
075   * @return the scale factor.
076   */
077  public double getFactor() {
078    return factor;
079  }
080
081  @Override
082  public UnitConverter concatenate(UnitConverter converter) {
083    if (!(converter instanceof MultiplyConverter))
084      return super.concatenate(converter);
085    double newfactor = factor * ((MultiplyConverter) converter).factor;
086    return newfactor == 1.0 ? IDENTITY : new MultiplyConverter(newfactor);
087  }
088
089  @Override
090  public MultiplyConverter inverse() {
091    return new MultiplyConverter(1.0 / factor);
092  }
093
094  @Override
095  public double convert(double value) {
096    return value * factor;
097  }
098
099  @Override
100  public final String toString() {
101    return "MultiplyConverter(" + factor + ")";
102  }
103
104  @Override
105  public boolean equals(Object obj) {
106    if (!(obj instanceof MultiplyConverter))
107      return false;
108    MultiplyConverter that = (MultiplyConverter) obj;
109    return this.factor == that.factor;
110  }
111
112  @Override
113  public int hashCode() {
114    long bits = Double.doubleToLongBits(factor);
115    return (int) (bits ^ (bits >>> 32));
116  }
117
118  public boolean isLinear() {
119    return true;
120  }
121
122  public Double getValue() {
123    return factor;
124  }
125}