1 package org.eclipse.aether.util.graph.transformer;
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.Collection;
23
24 import org.eclipse.aether.RepositoryException;
25 import org.eclipse.aether.util.graph.transformer.ConflictResolver.ConflictContext;
26 import org.eclipse.aether.util.graph.transformer.ConflictResolver.ConflictItem;
27 import org.eclipse.aether.util.graph.transformer.ConflictResolver.OptionalitySelector;
28
29 /**
30 * An optionality selector for use with {@link ConflictResolver}. In general, this selector only marks a dependency as
31 * optional if all its occurrences are optional. If however a direct dependency is involved, its optional flag is
32 * selected.
33 */
34 public final class SimpleOptionalitySelector
35 extends OptionalitySelector
36 {
37
38 /**
39 * Creates a new instance of this optionality selector.
40 */
41 public SimpleOptionalitySelector()
42 {
43 }
44
45 @Override
46 public void selectOptionality( ConflictContext context )
47 throws RepositoryException
48 {
49 boolean optional = chooseEffectiveOptionality( context.getItems() );
50 context.setOptional( optional );
51 }
52
53 private boolean chooseEffectiveOptionality( Collection<ConflictItem> items )
54 {
55 boolean optional = true;
56 for ( ConflictItem item : items )
57 {
58 if ( item.getDepth() <= 1 )
59 {
60 return item.getDependency().isOptional();
61 }
62 if ( ( item.getOptionalities() & ConflictItem.OPTIONAL_FALSE ) != 0 )
63 {
64 optional = false;
65 }
66 }
67 return optional;
68 }
69
70 }