1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2026 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library 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 GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.xpath.iterators;
21
22 import net.sf.saxon.om.AxisInfo;
23 import net.sf.saxon.om.NodeInfo;
24 import net.sf.saxon.tree.iter.AxisIterator;
25
26 /**
27 * Recursive-free implementation of the following axis iterator.
28 */
29 public class FollowingIterator implements AxisIterator {
30
31 /**
32 * Ancestor axis iterator.
33 */
34 private final AxisIterator ancestorEnum;
35 /**
36 * Following-sibling axis iterator.
37 */
38 private AxisIterator siblingEnum;
39 /**
40 * Descendant axis iterator.
41 */
42 private AxisIterator descendantEnum;
43
44 /**
45 * Create an iterator over the "following" axis.
46 *
47 * @param start the initial context node.
48 */
49 public FollowingIterator(NodeInfo start) {
50 ancestorEnum = start.iterateAxis(AxisInfo.ANCESTOR);
51 siblingEnum = start.iterateAxis(AxisInfo.FOLLOWING_SIBLING);
52 }
53
54 /**
55 * Get the next item in the sequence.
56 *
57 * @return the next Item. If there are no more nodes, return null.
58 */
59 @Override
60 public NodeInfo next() {
61 NodeInfo result = null;
62
63 do {
64 if (descendantEnum != null) {
65 result = descendantEnum.next();
66 }
67
68 if (result == null) {
69 result = siblingEnum.next();
70 if (result != null) {
71 descendantEnum = result.iterateAxis(AxisInfo.DESCENDANT);
72 }
73 }
74
75 if (result == null) {
76 final NodeInfo parent = ancestorEnum.next();
77 if (parent == null) {
78 break;
79 }
80 siblingEnum = parent.iterateAxis(AxisInfo.FOLLOWING_SIBLING);
81 }
82 } while (result == null);
83 return result;
84 }
85
86 }