001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.validator.util;
018
019import java.io.Serializable;
020
021/**
022 * Represents a collection of 64 boolean (on/off) flags.  Individual flags
023 * are represented by powers of 2.  For example,<br>
024 * Flag 1 = 1<br>
025 * Flag 2 = 2<br>
026 * Flag 3 = 4<br>
027 * Flag 4 = 8<br><br>
028 * or using shift operator to make numbering easier:<br>
029 * Flag 1 = 1 &lt;&lt; 0<br>
030 * Flag 2 = 1 &lt;&lt; 1<br>
031 * Flag 3 = 1 &lt;&lt; 2<br>
032 * Flag 4 = 1 &lt;&lt; 3<br>
033 *
034 * <p>
035 * There cannot be a flag with a value of 3 because that represents Flag 1
036 * and Flag 2 both being on/true.
037 * </p>
038 */
039public class Flags implements Serializable, Cloneable {
040
041    private static final long serialVersionUID = 8481587558770237995L;
042
043    /**
044     * Represents the current flag state.
045     */
046    private long flags;
047
048    /**
049     * Create a new Flags object.
050     */
051    public Flags() {
052    }
053
054    /**
055     * Initialize a new Flags object with the given flags.
056     *
057     * @param flags collection of boolean flags to represent.
058     */
059    public Flags(final long flags) {
060        this.flags = flags;
061    }
062
063    /**
064     * Turn off all flags.  This is a synonym for {@code turnOffAll()}.
065     *
066     * @since 1.1.1
067     */
068    public void clear() {
069        flags = 0;
070    }
071
072    /**
073     * Clone this Flags object.
074     *
075     * @return a copy of this object.
076     * @see Object#clone()
077     */
078    @Override
079    public Object clone() {
080        try {
081            return super.clone();
082        } catch (final CloneNotSupportedException e) {
083            throw new UnsupportedOperationException("Couldn't clone Flags object.", e);
084        }
085    }
086
087    /**
088     * Tests if two Flags objects are in the same state.
089     *
090     * @param obj object being tested
091     * @see Object#equals(Object)
092     * @return whether the objects are equal.
093     */
094    @Override
095    public boolean equals(final Object obj) {
096        if (this == obj) {
097            return true;
098        }
099        if (!(obj instanceof Flags)) {
100            return false;
101        }
102        final Flags other = (Flags) obj;
103        return flags == other.flags;
104    }
105
106    /**
107     * Returns the current flags.
108     *
109     * @return collection of boolean flags represented.
110     */
111    public long getFlags() {
112        return flags;
113    }
114
115    /**
116     * The hash code is based on the current state of the flags.
117     *
118     * @see Object#hashCode()
119     * @return the hash code for this object.
120     */
121    @Override
122    public int hashCode() {
123        return (int) flags;
124    }
125
126    /**
127     * Tests whether the given flag is off. If the flag is not a power of 2
128     * (for example, 3) this tests whether the combination of flags is off.
129     *
130     * @param flag Flag value to check.
131     * @return whether the specified flag value is off.
132     */
133    public boolean isOff(final long flag) {
134        return (flags & flag) == 0;
135    }
136
137    /**
138     * Tests whether the given flag is on. If the flag is not a power of 2
139     * (for example, 3) this tests whether the combination of flags is on.
140     *
141     * @param flag Flag value to check.
142     * @return whether the specified flag value is on.
143     */
144    public boolean isOn(final long flag) {
145        return (flags & flag) == flag;
146    }
147
148    /**
149     * Returns a 64 length String with the first flag on the right and the
150     * 64th flag on the left. A 1 indicates the flag is on, a 0 means it's
151     * off.
152     *
153     * @return string representation of this object.
154     */
155    @Override
156    public String toString() {
157        final StringBuilder bin = new StringBuilder(Long.toBinaryString(flags));
158        for (int i = 64 - bin.length(); i > 0; i--) { // CHECKSTYLE IGNORE MagicNumber
159            bin.insert(0, "0");
160        }
161        return bin.toString();
162    }
163
164    /**
165     * Turns off the given flag. If the flag is not a power of 2 (for example, 3) this
166     * turns off multiple flags.
167     *
168     * @param flag Flag value to turn off.
169     */
170    public void turnOff(final long flag) {
171        flags &= ~flag;
172    }
173
174    /**
175     * Turn off all flags.
176     */
177    public void turnOffAll() {
178        flags = 0;
179    }
180
181    /**
182     * Turns on the given flag. If the flag is not a power of 2 (for example, 3) this
183     * turns on multiple flags.
184     *
185     * @param flag Flag value to turn on.
186     */
187    public void turnOn(final long flag) {
188        flags |= flag;
189    }
190
191    /**
192     * Turn on all 64 flags.
193     */
194    public void turnOnAll() {
195        flags = 0xFFFFFFFFFFFFFFFFL;
196    }
197
198}