1 package org.djunits.unit;
2
3 import org.djunits.unit.scale.LinearScale;
4 import org.djunits.unit.scale.Scale;
5 import org.djunits.unit.scale.StandardScale;
6 import org.djunits.unit.unitsystem.UnitSystem;
7
8 /**
9 * A linear unit with easy-access constructor with a linear factor, and access to the linear factor. <br>
10 * A linear unit is a unit that is linearly related to the SI standard unit. E.g. Mile is linearly related to meter (the SI unit
11 * for length). Unlike temperature in degrees Celsius which is <strong>not</strong> linearly related to the Kelvin (the SI unit
12 * for temperature).
13 * <p>
14 * Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
15 * BSD-style license. See <a href="http://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
16 * </p>
17 * $LastChangedDate: 2015-07-24 02:58:59 +0200 (Fri, 24 Jul 2015) $, @version $Revision: 1147 $, by $Author: averbraeck $,
18 * initial version Oct 11, 2015 <br>
19 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
20 * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
21 * @param <U> the linear Unit.
22 */
23 public abstract class LinearUnit<U extends LinearUnit<U>> extends Unit<U>
24 {
25 /** */
26 private static final long serialVersionUID = 20151011L;
27
28 /**
29 * Build a standard unit with a linear scale and create the fields for that unit. For a standard unit, a UnitException is
30 * silently ignored.
31 * @param abbreviationKey String; the key to the locale file for the abbreviation of the unit
32 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
33 */
34 public LinearUnit(final String abbreviationKey, final UnitSystem unitSystem)
35 {
36 super(abbreviationKey, unitSystem);
37 }
38
39 /**
40 * Build a standard unit with a linear conversion factor to another unit.
41 * @param abbreviationKey String; the key to the locale file for the abbreviation of the unit
42 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
43 * @param referenceUnit U; the unit to convert to
44 * @param scaleFactorToReferenceUnit double; multiply a value in this unit by the factor to convert to the given reference
45 * unit
46 */
47 protected LinearUnit(final String abbreviationKey, final UnitSystem unitSystem, final U referenceUnit,
48 final double scaleFactorToReferenceUnit)
49 {
50 super(abbreviationKey, unitSystem, referenceUnit == null ? StandardScale.SCALE
51 : new LinearScale(referenceUnit.getScale().getConversionFactorToStandardUnit() * scaleFactorToReferenceUnit));
52 }
53
54 /**
55 * Build a standard unit with a specific conversion scale to/from the standard unit.
56 * @param abbreviationKey String; the key to the locale file for the abbreviation of the unit
57 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
58 * @param scale Scale; the conversion scale to use for this unit
59 */
60 protected LinearUnit(final String abbreviationKey, final UnitSystem unitSystem, final Scale scale)
61 {
62 super(abbreviationKey, unitSystem, scale);
63 }
64
65 /**
66 * Build a user-defined unit with a linear scale and create the fields for that unit.
67 * @param name String; the name of the unit
68 * @param abbreviation String; the abbreviation of the unit
69 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
70 */
71 public LinearUnit(final String name, final String abbreviation, final UnitSystem unitSystem)
72 {
73 super(name, abbreviation, unitSystem);
74 }
75
76 /**
77 * Build a user-defined unit with a linear conversion factor to another unit.
78 * @param name String; the name of the unit
79 * @param abbreviation String; the abbreviation of the unit
80 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
81 * @param referenceUnit U; the unit to convert to
82 * @param scaleFactorToReferenceUnit double; multiply a value in this unit by the factor to convert to the given reference
83 * unit
84 */
85 protected LinearUnit(final String name, final String abbreviation, final UnitSystem unitSystem, final U referenceUnit,
86 final double scaleFactorToReferenceUnit)
87 {
88 super(name, abbreviation, unitSystem, referenceUnit == null ? StandardScale.SCALE
89 : new LinearScale(referenceUnit.getScale().getConversionFactorToStandardUnit() * scaleFactorToReferenceUnit));
90 }
91
92 /**
93 * Build a user-defined unit with a specific conversion scale to/from the standard unit.
94 * @param name String; the name of the unit
95 * @param abbreviation String; the abbreviation of the unit
96 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
97 * @param scale Scale; the conversion scale to use for this unit
98 */
99 protected LinearUnit(final String name, final String abbreviation, final UnitSystem unitSystem, final Scale scale)
100 {
101 super(name, abbreviation, unitSystem, scale);
102 }
103
104 /** {@inheritDoc} */
105 @Override
106 @SuppressWarnings("checkstyle:designforextension")
107 public LinearScale getScale()
108 {
109 return (LinearScale) super.getScale();
110 }
111
112 /**
113 * @return the conversion factor to the standard unit (e.g., the SI unit)
114 */
115 public final double getScaleFactor()
116 {
117 return getScale().getConversionFactorToStandardUnit();
118 }
119
120 /** {@inheritDoc} */
121 @Override
122 public int hashCode()
123 {
124 final int prime = 31;
125 int result = super.hashCode();
126 long temp;
127 temp = Double.doubleToLongBits(this.getScaleFactor());
128 result = prime * result + (int) (temp ^ (temp >>> 32));
129 return result;
130 }
131
132 /** {@inheritDoc} */
133 @SuppressWarnings("checkstyle:needbraces")
134 @Override
135 public boolean equals(final Object obj)
136 {
137 if (this == obj)
138 return true;
139 if (!super.equals(obj))
140 return false;
141 if (getClass() != obj.getClass())
142 return false;
143 LinearUnit<?> other = (LinearUnit<?>) obj;
144 if (Double.doubleToLongBits(this.getScaleFactor()) != Double.doubleToLongBits(other.getScaleFactor()))
145 return false;
146 return true;
147 }
148
149 /** {@inheritDoc} */
150 @SuppressWarnings("checkstyle:needbraces")
151 @Override
152 public boolean equalsIgnoreNaming(final Object obj)
153 {
154 if (this == obj)
155 return true;
156 if (getClass() != obj.getClass())
157 return false;
158 LinearUnit<?> other = (LinearUnit<?>) obj;
159 if (Double.doubleToLongBits(getScaleFactor()) != Double.doubleToLongBits(other.getScaleFactor()))
160 return false;
161 return true;
162 }
163
164 }