1 package org.apache.maven.shared.dependency.graph.filter;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.Collections;
23 import java.util.List;
24
25 import org.apache.maven.shared.dependency.graph.DependencyNode;
26
27 /**
28 * A dependency node filter than only accepts nodes that are ancestors of, or equal to, a given list of nodes.
29 *
30 * @author <a href="mailto:markhobson@gmail.com">Mark Hobson</a>
31 * @version $Id$
32 * @since 1.1
33 */
34 public class AncestorOrSelfDependencyNodeFilter
35 implements DependencyNodeFilter
36 {
37 // fields -----------------------------------------------------------------
38
39 /**
40 * The list of nodes that this filter accepts ancestors-or-self of.
41 */
42 private final List<DependencyNode> descendantNodes;
43
44 // constructors -----------------------------------------------------------
45
46 public AncestorOrSelfDependencyNodeFilter( DependencyNode descendantNode )
47 {
48 this( Collections.singletonList( descendantNode ) );
49 }
50
51 /**
52 * Creates a dependency node filter that only accepts nodes that are ancestors of, or equal to, the specified list
53 * of nodes.
54 *
55 * @param descendantNodes the list of nodes to accept ancestors-or-self of
56 */
57 public AncestorOrSelfDependencyNodeFilter( List<DependencyNode> descendantNodes )
58 {
59 this.descendantNodes = descendantNodes;
60 }
61
62 // DependencyNodeFilter methods -------------------------------------------
63
64 /**
65 * {@inheritDoc}
66 */
67 @Override
68 public boolean accept( DependencyNode node )
69 {
70 for ( DependencyNode descendantNode : descendantNodes )
71 {
72 if ( isAncestorOrSelf( node, descendantNode ) )
73 {
74 return true;
75 }
76 }
77
78 return false;
79 }
80
81 // private methods --------------------------------------------------------
82
83 /**
84 * Gets whether the first dependency node is an ancestor-or-self of the second.
85 *
86 * @param ancestorNode the ancestor-or-self dependency node
87 * @param descendantNode the dependency node to test
88 * @return <code>true</code> if <code>ancestorNode</code> is an ancestor, or equal to, <code>descendantNode</code>
89 */
90 private boolean isAncestorOrSelf( DependencyNode ancestorNode, DependencyNode descendantNode )
91 {
92 boolean ancestor = false;
93
94 while ( !ancestor && descendantNode != null )
95 {
96 ancestor = ancestorNode.equals( descendantNode );
97
98 descendantNode = descendantNode.getParent();
99 }
100
101 return ancestor;
102 }
103 }