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.data;
031
032import java.util.ArrayList;
033import java.util.Arrays;
034import java.util.List;
035import java.util.Map;
036
037/**
038 * An abstract {@link DataSource} backed by multiple lists of data.
039 * 
040 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
041 * @param <DATATYPE>
042 *            the data type which can be returned
043 * @param <ELEMENTTYPE>
044 *            the datatype of the underlying lists
045 * 
046 */
047public abstract class AbstractMultiListDataSource<DATATYPE, ELEMENTTYPE> extends AbstractDataSource<DATATYPE> {
048        protected List<? extends List<ELEMENTTYPE>> data;
049
050        /**
051         * Construct with the given lists of data
052         * 
053         * @param data
054         *            the data
055         */
056        public AbstractMultiListDataSource(List<? extends List<ELEMENTTYPE>> data) {
057                this.data = data;
058        }
059
060        /**
061         * Construct with the given lists of data
062         * 
063         * @param data
064         *            the data
065         */
066        public AbstractMultiListDataSource(List<ELEMENTTYPE>... data) {
067                this.data = Arrays.asList(data);
068        }
069
070        /**
071         * Construct with the given map of data. The keys are ignored, and only the
072         * values are used.
073         * 
074         * @param data
075         *            the data
076         */
077        public AbstractMultiListDataSource(Map<?, ? extends List<ELEMENTTYPE>> data) {
078                this.data = new ArrayList<List<ELEMENTTYPE>>(data.values());
079        }
080
081        @Override
082        public void getData(int startRow, int stopRow, DATATYPE[] data) {
083                for (int i = 0, row = startRow; row < stopRow; row++, i++) {
084                        data[i] = getData(row);
085                }
086        }
087
088        @Override
089        public DATATYPE getData(int row) {
090                int cumsum = 0;
091
092                for (int i = 0; i < data.size(); i++) {
093                        final int sz = data.get(i).size();
094
095                        if (row < cumsum + sz) {
096                                return convert(data.get(i).get(row - cumsum));
097                        }
098
099                        cumsum += sz;
100                }
101
102                throw new IndexOutOfBoundsException();
103        }
104
105        /**
106         * Convert an item's type
107         * 
108         * @param ele
109         *            the input item
110         * @return the converted item
111         */
112        protected abstract DATATYPE convert(ELEMENTTYPE ele);
113
114        @Override
115        public int numRows() {
116                int sum = 0;
117
118                for (final List<ELEMENTTYPE> d : data)
119                        sum += d.size();
120
121                return sum;
122        }
123}