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.Operation;
034
035/**
036 * An adaptor that allows an {@link Operation} to be applied to a single element
037 * of the {@link Context}.
038 * 
039 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
040 * 
041 * @param <T>
042 *            Type of element that the operation is applied to
043 */
044public class ContextOperationAdaptor<T> extends ContextAdaptor<Operation<T>, T, T> implements Operation<Context> {
045        /**
046         * Construct with the given operation and extractor
047         * 
048         * @param inner
049         *            the operation
050         * @param extract
051         *            the extractor
052         */
053        public ContextOperationAdaptor(Operation<T> inner, ContextExtractor<T> extract)
054        {
055                super(inner, extract, null);
056        }
057
058        /**
059         * Construct with the given operation. The extractor is a
060         * {@link KeyContextExtractor} created from the given key.
061         * 
062         * @param inner
063         *            the operation
064         * @param extract
065         *            the key
066         */
067        public ContextOperationAdaptor(Operation<T> inner, String extract)
068        {
069                super(inner, extract, extract);
070        }
071
072        @Override
073        public void perform(Context object) {
074                inner.perform(extract.extract(object));
075        }
076
077        /**
078         * Helper to create a new {@link ContextOperationAdaptor}.
079         * 
080         * @param operation
081         *            the operation
082         * @param extract
083         *            the key to extract from
084         * 
085         * @see ContextOperationAdaptor#ContextOperationAdaptor(Operation,
086         *      ContextExtractor)
087         * 
088         * @return the context operation
089         */
090        public static <IN> Operation<Context> create(Operation<IN> operation, String extract) {
091                return new ContextOperationAdaptor<IN>(operation, extract);
092        }
093}