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.Function;
034
035/**
036 * Base class that holds the elements required to adapt something (i.e. a
037 * {@link Function}) to work around around a single element of a {@link Context}
038 * and output to a potentially different key of that {@link Context}.
039 * <p>
040 * This base class just holds the parts required for the adaption (the object
041 * being adapted, and the {@link ContextExtractor} and
042 * {@link ContextInsertor}), but doesn't actually provide any
043 * functionality.
044 * 
045 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
046 * 
047 * @param <ADAPTED>
048 *            The type of object being adapted
049 * @param <IN>
050 *            The input type of the object being adapted
051 * @param <OUT>
052 *            The output type of the object being adapted
053 */
054public abstract class ContextAdaptor<ADAPTED, IN, OUT> {
055        protected ADAPTED inner;
056        protected ContextExtractor<IN> extract;
057        protected ContextInsertor<OUT> insert;
058
059        /**
060         * Construct with the given options.
061         * 
062         * @param inner
063         *            the object being adapted
064         * @param extract
065         *            the extractor
066         * @param insert
067         *            the insertor
068         */
069        public ContextAdaptor(ADAPTED inner, ContextExtractor<IN> extract, ContextInsertor<OUT> insert) {
070                this.inner = inner;
071                this.insert = insert;
072                this.extract = extract;
073        }
074
075        /**
076         * Construct with the given object to adapt. The insertor and extractor are
077         * created from the given keys.
078         * 
079         * @param inner
080         *            the object being adapted
081         * @param keyin
082         *            the key to extract from the context to produce the input for
083         *            the object
084         * @param keyout
085         *            the key to insert with the the output for the object
086         */
087        public ContextAdaptor(ADAPTED inner, String keyin, String keyout) {
088                this.inner = inner;
089                this.extract = new KeyContextExtractor<IN>(keyin);
090                this.insert = new KeyContextInsertor<OUT>(keyout);
091        }
092}