1 /*
2 * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
3 * the spring framework, http://el4j.sf.net
4 * Copyright (C) 2006 by ELCA Informatique SA, Av. de la Harpe 22-24,
5 * 1000 Lausanne, Switzerland, http://www.elca.ch
6 *
7 * EL4J is published under the GNU Lesser General Public License (LGPL)
8 * Version 2.1. See http://www.gnu.org/licenses/
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU Lesser General Public License for more details.
14 *
15 * For alternative licensing, please contact info@elca.ch
16 */
17 package ch.elca.el4j.util.collections.impl;
18
19 import java.util.AbstractList;
20 import java.util.List;
21
22 import ch.elca.el4j.util.codingsupport.CollectionUtils;
23 import ch.elca.el4j.util.collections.FilteredList;
24 import ch.elca.el4j.util.collections.TransformedList;
25 import ch.elca.el4j.util.collections.helpers.Filter;
26 import ch.elca.el4j.util.collections.helpers.Function;
27
28 /**
29 * Default implementation of {@link TransformedList}.
30 *
31 * @param <I> the backing list's element type
32 * @param <O> this list's element type
33 *
34 * @svnLink $Revision: 3874 $;$Date: 2009-08-04 14:25:40 +0200 (Di, 04. Aug 2009) $;$Author: swismer $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/core/src/main/java/ch/elca/el4j/util/collections/impl/DefaultTransformedList.java $
35 *
36 * @author Adrian Moos (AMS)
37 */
38 public class DefaultTransformedList<I, O> extends AbstractList<O>
39 implements TransformedList<I, O> {
40
41 /** The backing List. */
42 private List<? extends I> m_backing;
43
44 /** The backing function. */
45 private Function<? super I, O> m_function;
46
47 /** Constructor.
48 * @param backing the backing list
49 * @param function the transformation function
50 */
51 public DefaultTransformedList(List<? extends I> backing,
52 Function<? super I, O> function) {
53
54 m_backing = backing;
55 m_function = function;
56 }
57
58 /**
59 * Returns an element of this list.
60 * @param index the index of the element to return
61 * @return the element
62 */
63 public O get(int index) {
64 return m_function.apply(m_backing.get(index));
65 }
66
67 /**
68 * {@inheritDoc}
69 */
70 public int size() { return m_backing.size(); }
71
72 /**
73 * {@inheritDoc}
74 */
75 public void swap(int i, int j) {
76 CollectionUtils.swap(m_backing, i, j);
77 }
78
79 /**
80 * {@inheritDoc}
81 */
82 public void orderLike(List<? extends O> example) {
83 CollectionUtils.orderLike(this, example);
84 }
85
86 /**
87 * {@inheritDoc}
88 */
89 @SuppressWarnings("unchecked")
90 public O[] toArray(Class<O> c) {
91 return CollectionUtils.toArray(this, c);
92 }
93
94 /**
95 * {@inheritDoc}
96 */
97 public <T> TransformedList<O, T> mapped(
98 Function<? super O, T> function) {
99 return new DefaultTransformedList<O, T>(this, function);
100 }
101
102 /**
103 * {@inheritDoc}
104 */
105 public List<? extends I> getBacking() {
106 return m_backing;
107 }
108
109 /** {@inheritDoc} */
110 public FilteredList<O> filtered(Filter<? super O> filter) {
111 return new DefaultFilteredList<O>(this, filter);
112 }
113 }