001    /*
002     * Jpkg - Java library and tools for operating system package creation.
003     *
004     * Copyright (c) 2007-2008 Three Rings Design, Inc.
005     * All rights reserved.
006     *
007     * Redistribution and use in source and binary forms, with or without
008     * modification, are permitted provided that the following conditions
009     * are met:
010     * 1. Redistributions of source code must retain the above copyright
011     *    notice, this list of conditions and the following disclaimer.
012     * 2. Redistributions in binary form must reproduce the above copyright
013     *    notice, this list of conditions and the following disclaimer in the
014     *    documentation and/or other materials provided with the distribution.
015     * 3. Neither the name of the copyright owner nor the names of contributors
016     *    may be used to endorse or promote products derived from this software
017     *    without specific prior written permission.
018     *
019     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
020     * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
021     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
022     * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
023     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
024     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
025     * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
026     * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
027     * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
028     * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
029     * POSSIBILITY OF SUCH DAMAGE.
030     */
031    package com.threerings.antidote;
032    
033    
034    /**
035     * A static helper utility for dealing with mutable Ant data.
036     */
037    public class MutabilityHelper
038    {
039        /**
040         * Checks to see if the supplied Object is set, e.g. not null.
041         * It is expected this method would be used as a static import to increase readability as in:
042         * if (objectIsSet(object))
043         */
044        public static boolean objectIsSet (Object object)
045        {
046            if (object != null) {
047                return true;
048            }
049            return false;
050        }
051    
052        /**
053         * Checks to see if the supplied Object is not set, e.g. null.
054         * It is expected this method would be used as a static import to increase readability as in:
055         * if (objectIsNotSet(object))
056         */
057        public static boolean objectIsNotSet (Object object)
058        {
059            return !objectIsSet(object);
060        }
061    
062        /**
063         * Return a {@link SetStatus} enum describing the "set" state, of the list of
064         * supplied {@link Mutable} objects.
065         */
066        public static SetStatus areMutablesSet (Mutable...mutables)
067        {
068            int unset = 0;
069            for (final Mutable mutable : mutables) {
070                if (mutable.isNotSet()) {
071                    unset++;
072                }
073            }
074    
075            if (unset == mutables.length) {
076                return SetStatus.ALL_UNSET;
077    
078            } else if (unset == 0) {
079                return SetStatus.ALL_SET;
080    
081            } else {
082                return SetStatus.SOME_UNSET;
083            }
084        }
085    
086        /**
087         * Alerts the developer via an {@link RequiresValidationException} that an object was accessed before
088         * validate() or validateField() was called, which is the method where the object is being set.
089         * This is a workaround for Ant's mutable state.
090         * It is expected this method would be used as a static import to increase readability as in:
091         * requiresValidation(object);
092         * @throws RequiresValidationException If the supplied object is null
093         */
094        public static void requiresValidation (Object notNull)
095        {
096            if (objectIsNotSet(notNull)) {
097                throw new RequiresValidationException();
098            }
099        }
100    }