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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.maven.plugins.dependency.tree;
20  
21  import java.io.Writer;
22  import java.util.List;
23  
24  import org.apache.maven.shared.dependency.graph.DependencyNode;
25  import org.apache.maven.shared.dependency.graph.traversal.DependencyNodeVisitor;
26  
27  /**
28   * A dependency node visitor that serializes visited nodes to <a href="https://en.wikipedia.org/wiki/DOT_language">DOT
29   * format</a>
30   *
31   * @author <a href="mailto:pi.songs@gmail.com">Pi Song</a>
32   * @since 2.1
33   */
34  public class DOTDependencyNodeVisitor extends AbstractSerializingVisitor implements DependencyNodeVisitor {
35  
36      /**
37       * Constructor.
38       *
39       * @param writer the writer to write to.
40       */
41      public DOTDependencyNodeVisitor(Writer writer) {
42          super(writer);
43      }
44  
45      /**
46       * {@inheritDoc}
47       */
48      @Override
49      public boolean visit(DependencyNode node) {
50          if (node.getParent() == null || node.getParent() == node) {
51              writer.write("digraph \"" + node.toNodeString() + "\" { " + System.lineSeparator());
52          }
53  
54          // Generate "currentNode -> Child" lines
55  
56          List<DependencyNode> children = node.getChildren();
57  
58          for (DependencyNode child : children) {
59              writer.println("\t\"" + node.toNodeString() + "\" -> \"" + child.toNodeString() + "\" ; ");
60          }
61  
62          return true;
63      }
64  
65      /**
66       * {@inheritDoc}
67       */
68      @Override
69      public boolean endVisit(DependencyNode node) {
70          if (node.getParent() == null || node.getParent() == node) {
71              writer.write(" } ");
72          }
73          return true;
74      }
75  }