001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.util.function.context;
031
032import org.openimaj.util.data.Context;
033import org.openimaj.util.function.Predicate;
034
035/**
036 * An adaptor that allows a {@link Predicate} to be applied to a {@link Context}
037 * , based on a single element of the {@link Context}.
038 * 
039 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
040 * 
041 * @param <T>
042 *            Type processed by the predicate
043 */
044public class ContextPredicateAdaptor<T> extends ContextAdaptor<Predicate<T>, T, T> implements Predicate<Context> {
045        /**
046         * Construct with the given options.
047         * 
048         * @param inner
049         *            the predicate
050         * @param extract
051         *            the extractor
052         * @param insert
053         *            the insertor
054         */
055        public ContextPredicateAdaptor(Predicate<T> inner, ContextExtractor<T> extract, ContextInsertor<T> insert)
056        {
057                super(inner, extract, insert);
058        }
059
060        /**
061         * Construct with the given predicate. The insertor and extractor are
062         * created from the given keys.
063         * 
064         * @param inner
065         *            the predicate
066         * @param extract
067         *            the key to extract from the context to produce the input for
068         *            the object
069         * @param insert
070         *            the key to insert with the the output for the object
071         */
072        public ContextPredicateAdaptor(Predicate<T> inner, String extract, String insert)
073        {
074                super(inner, extract, insert);
075        }
076
077        /**
078         * Construct with the given predicate. The insertor and extractor are
079         * created from the same key, so the output will overwrite the input.
080         * 
081         * @param inner
082         *            the object being adapted
083         * @param both
084         *            the key to extract/insert
085         */
086        public ContextPredicateAdaptor(Predicate<T> inner, String both)
087        {
088                super(inner, both, both);
089        }
090
091        @Override
092        public boolean test(Context in) {
093                return inner.test(this.extract.extract(in));
094        }
095}