001    /**
002     * Copyright (c) 2000-2013 Liferay, Inc. All rights reserved.
003     *
004     * This library is free software; you can redistribute it and/or modify it under
005     * the terms of the GNU Lesser General Public License as published by the Free
006     * Software Foundation; either version 2.1 of the License, or (at your option)
007     * any later version.
008     *
009     * This library is distributed in the hope that it will be useful, but WITHOUT
010     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
011     * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
012     * details.
013     */
014    
015    package com.liferay.portal.kernel.increment;
016    
017    /**
018     * @author Zsolt Berentey
019     */
020    public class NumberIncrement implements Increment<Number> {
021    
022            public NumberIncrement(Number value) {
023                    _value = value;
024            }
025    
026            @Override
027            public void decrease(Number delta) {
028                    _value = subtract(delta);
029            }
030    
031            @Override
032            public Increment<Number> decreaseForNew(Number delta) {
033                    return new NumberIncrement(subtract(delta));
034            }
035    
036            @Override
037            public Number getValue() {
038                    return _value;
039            }
040    
041            @Override
042            public void increase(Number delta) {
043                    _value = add(delta);
044            }
045    
046            @Override
047            public Increment<Number> increaseForNew(Number delta) {
048                    return new NumberIncrement(add(delta));
049            }
050    
051            @Override
052            public void setValue(Number value) {
053                    _value = value;
054            }
055    
056            protected Number add(Number delta) {
057                    if (delta instanceof Double) {
058                            return addAsDouble(delta);
059                    }
060                    else if (delta instanceof Integer) {
061                            return addAsInteger(delta);
062                    }
063                    else if (delta instanceof Long) {
064                            return addAsLong(delta);
065                    }
066    
067                    return _value;
068            }
069    
070            protected Number addAsDouble(Number delta) {
071                    if (delta == null) {
072                            return _value;
073                    }
074    
075                    return _value.doubleValue() + delta.doubleValue();
076            }
077    
078            protected Number addAsInteger(Number delta) {
079                    if (delta == null) {
080                            return _value;
081                    }
082    
083                    return _value.intValue() + delta.intValue();
084            }
085    
086            protected Number addAsLong(Number delta) {
087                    if (delta == null) {
088                            return _value;
089                    }
090    
091                    return _value.longValue() + delta.longValue();
092            }
093    
094            protected Number subtract(Number delta) {
095                    if (delta instanceof Double) {
096                            return subtractAsDouble(delta);
097                    }
098                    else if (delta instanceof Integer) {
099                            return subtractAsInteger(delta);
100                    }
101                    else if (delta instanceof Long) {
102                            return subtractAsLong(delta);
103                    }
104    
105                    return _value;
106            }
107    
108            protected Number subtractAsDouble(Number delta) {
109                    if (delta == null) {
110                            return _value;
111                    }
112    
113                    return _value.doubleValue() - delta.doubleValue();
114            }
115    
116            protected Number subtractAsInteger(Number delta) {
117                    if (delta == null) {
118                            return _value;
119                    }
120    
121                    return _value.intValue() - delta.intValue();
122            }
123    
124            protected Number subtractAsLong(Number delta) {
125                    if (delta == null) {
126                            return _value;
127                    }
128    
129                    return _value.longValue() - delta.longValue();
130            }
131    
132            private Number _value = 0;
133    
134    }