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     * @since 1.1.1
066     */
067    public void clear() {
068        flags = 0;
069    }
070
071    /**
072     * Clone this Flags object.
073     *
074     * @return a copy of this object.
075     * @see Object#clone()
076     */
077    @Override
078    public Object clone() {
079        try {
080            return super.clone();
081        } catch (final CloneNotSupportedException e) {
082            throw new UnsupportedOperationException("Couldn't clone Flags object.", e);
083        }
084    }
085
086    /**
087     * Tests if two Flags objects are in the same state.
088     * @param obj object being tested
089     * @see Object#equals(Object)
090     * @return whether the objects are equal.
091     */
092    @Override
093    public boolean equals(final Object obj) {
094        if (this == obj) {
095            return true;
096        }
097        if (!(obj instanceof Flags)) {
098            return false;
099        }
100        final Flags other = (Flags) obj;
101        return flags == other.flags;
102    }
103
104    /**
105     * Returns the current flags.
106     *
107     * @return collection of boolean flags represented.
108     */
109    public long getFlags() {
110        return flags;
111    }
112
113    /**
114     * The hash code is based on the current state of the flags.
115     * @see Object#hashCode()
116     * @return the hash code for this object.
117     */
118    @Override
119    public int hashCode() {
120        return (int) flags;
121    }
122
123    /**
124     * Tests whether the given flag is off. If the flag is not a power of 2
125     * (for example, 3) this tests whether the combination of flags is off.
126     *
127     * @param flag Flag value to check.
128     * @return whether the specified flag value is off.
129     */
130    public boolean isOff(final long flag) {
131        return (flags & flag) == 0;
132    }
133
134    /**
135     * Tests whether the given flag is on. If the flag is not a power of 2
136     * (for example, 3) this tests whether the combination of flags is on.
137     *
138     * @param flag Flag value to check.
139     * @return whether the specified flag value is on.
140     */
141    public boolean isOn(final long flag) {
142        return (flags & flag) == flag;
143    }
144
145    /**
146     * Returns a 64 length String with the first flag on the right and the
147     * 64th flag on the left. A 1 indicates the flag is on, a 0 means it's
148     * off.
149     *
150     * @return string representation of this object.
151     */
152    @Override
153    public String toString() {
154        final StringBuilder bin = new StringBuilder(Long.toBinaryString(flags));
155        for (int i = 64 - bin.length(); i > 0; i--) { // CHECKSTYLE IGNORE MagicNumber
156            bin.insert(0, "0");
157        }
158        return bin.toString();
159    }
160
161    /**
162     * Turns off the given flag. If the flag is not a power of 2 (for example, 3) this
163     * turns off multiple flags.
164     *
165     * @param flag Flag value to turn off.
166     */
167    public void turnOff(final long flag) {
168        flags &= ~flag;
169    }
170
171    /**
172     * Turn off all flags.
173     */
174    public void turnOffAll() {
175        flags = 0;
176    }
177
178    /**
179     * Turns on the given flag. If the flag is not a power of 2 (for example, 3) this
180     * turns on multiple flags.
181     *
182     * @param flag Flag value to turn on.
183     */
184    public void turnOn(final long flag) {
185        flags |= flag;
186    }
187
188    /**
189     * Turn on all 64 flags.
190     */
191    public void turnOnAll() {
192        flags = 0xFFFFFFFFFFFFFFFFL;
193    }
194
195}