1 /**********************************************
2 * Copyright (C) 2011 Lukas laag
3 * This file is part of lib-gwt-file.
4 *
5 * lib-gwt-file is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
9 *
10 * lib-gwt-file 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 * You should have received a copy of the GNU Lesser General Public License
16 * along with lib-gwt-file. If not, see http://www.gnu.org/licenses/
17 **********************************************/
18 /**
19 * Documentation is adapted from W3C spec and content available from
20 * http://developer.mozilla.org under http://creativecommons.org/licenses/by-sa/2.5/
21 */
22 package org.vectomatic.file;
23
24 import java.util.Iterator;
25
26 import org.vectomatic.file.impl.FileListImpl;
27
28 /**
29 * An object of this type is returned by the files property of the HTML input element;
30 * this lets you access the list of files selected with the <input type="file"> element.
31 * It's also used for a list of files dropped into web content when using the drag and drop API;
32 * see the {@link org.vectomatic.dnd.DataTransferExt} object for details on this usage.
33 */
34 public class FileList implements Iterable<File> {
35 private FileListImpl impl;
36
37 /**
38 * Constructor. Do not call this constructor directly
39 * new FileList are generated automatically where needed in the API.
40 * @param impl the underlying implementation object.
41 */
42 public FileList(FileListImpl impl) {
43 this.impl = impl;
44 }
45
46 /**
47 * Returns an iterator over the {@link org.vectomatic.file.File}
48 * elements in this list in proper sequence.
49 *
50 * <p>This implementation returns a straightforward implementation of the
51 * iterator interface, relying on the backing list's {@code getLength()},
52 * and {@code getItem(int)} methods.
53 *
54 * <p>Note that the iterator returned by this method will throw an
55 * {@code UnsupportedOperationException} in response to its
56 * {@code remove} method.
57 *
58 * @return an iterator over the {@link org.vectomatic.file.File}
59 * elements in this list in proper sequence
60 */
61 @Override
62 public Iterator<File> iterator() {
63 return new Iterator<File>() {
64 private int index;
65
66 @Override
67 public boolean hasNext() {
68 return index < getLength();
69 }
70
71 @Override
72 public File next() {
73 return getItem(index++);
74 }
75
76 @Override
77 public void remove() {
78 throw new UnsupportedOperationException();
79 }
80 };
81 }
82 /**
83 * Returns the <code>index</code>th item in the collection. If
84 * <code>index</code> is greater than or equal to the number of nodes in
85 * the list, this returns <code>null</code>.
86 * @param index Index into the collection.
87 * @return The node at the <code>index</code>th position in the
88 * <code>FileList</code>, or <code>null</code> if that is not a valid
89 * index.
90 */
91 public final File getItem(int index) {
92 return impl.getItem(index);
93 }
94 /**
95 * The number of nodes in the list. The range of valid child node indices
96 * is 0 to <code>length-1</code> inclusive.
97 */
98 public final int getLength() {
99 return impl.getLength();
100 }
101 }