001    /**
002     * Copyright (c) 2010, SIB. All rights reserved.
003     * 
004     * SIB (Swiss Institute of Bioinformatics) - http://www.isb-sib.ch Host -
005     * https://sourceforge.net/projects/javaprotlib/
006     * 
007     * Redistribution and use in source and binary forms, with or without
008     * modification, are permitted provided that the following conditions are met:
009     * Redistributions of source code must retain the above copyright notice, this
010     * list of conditions and the following disclaimer. Redistributions in binary
011     * form must reproduce the above copyright notice, this list of conditions and
012     * the following disclaimer in the documentation and/or other materials provided
013     * with the distribution. Neither the name of the SIB/GENEBIO nor the names of
014     * its contributors may be used to endorse or promote products derived from this
015     * software without specific prior written permission.
016     * 
017     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
018     * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
019     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
020     * ARE DISCLAIMED. IN NO EVENT SHALL SIB/GENEBIO BE LIABLE FOR ANY DIRECT,
021     * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
022     * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
023     * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
024     * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
025     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
026     * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
027     */
028    package org.expasy.jpl.commons.base;
029    
030    
031    import java.io.Serializable;
032    
033    
034    /**
035     * {@code CounterImpl} is a simple counter and a better alternative than {@code
036     * Integer} as a new instance is created each time you want to set the value.
037     * 
038     * @author nikitin
039     * 
040     * @version 1.0
041     * 
042     */
043    public final class CounterImpl implements Counter, Resetable, ExplicitlyCloneable,
044        Serializable {
045            
046            private static final long serialVersionUID = 7831797543622859629L;
047            
048            private int count;
049            
050            private CounterImpl(int start) {
051                    count = start;
052            }
053            
054            /**
055             * A basic static factory method.
056             * 
057             * @return a new instance of {@code CounterImpl} initialized to 0.
058             */
059            public static CounterImpl newInstance() {
060                    return new CounterImpl(0);
061            }
062            
063            /**
064             * A type-conversion static factory method.
065             * 
066             * @return a new instance of {@code CounterImpl} with the given value.
067             */
068            public static CounterImpl valueOf(int start) {
069                    return new CounterImpl(start);
070            }
071            
072            /** @see Resetable#reset() */
073            public void reset() {
074                    count = 0;
075            }
076            
077            /**
078             * Creates and returns a copy of this {@code CounterImpl}.
079             * 
080             * @see Object#clone()
081             */
082            public CounterImpl clone() {
083                    CounterImpl clone = null;
084                    try {
085                            clone = (CounterImpl) super.clone();
086                            clone.count = count;
087                    } catch (CloneNotSupportedException e) {
088                            throw new AssertionError(); // cannot happen
089                    }
090                    return clone;
091            }
092            
093            public boolean equals(Object o) {
094                    if (o instanceof CounterImpl) {
095                            if (((CounterImpl) o).count == count) {
096                                    return true;
097                            }
098                    }
099                    return false;
100            }
101            
102            public int hashCode() {
103                    return count;
104            }
105            
106            /**
107             * Increment counter by 1.
108             */
109            public void increment() {
110                    count++;
111            }
112            
113            /**
114             * Increment counter by {@code inc}.
115             */
116            public void increment(int inc) {
117                    count += inc;
118            }
119            
120            /**
121             * Decrement counter by 1.
122             */
123            public void decrement() {
124                    count--;
125            }
126            
127            /**
128             * Decrement counter by {@code dec}.
129             */
130            public void decrement(int dec) {
131                    count -= dec;
132            }
133            
134            /**
135             * @return counter value.
136             */
137            public int getCount() {
138                    return count;
139            }
140            
141            public String toString() {
142                    return "x" + count;
143            }
144    }