1 /*
2  * Copyright (C) 2007-2010 Júlio Vilmar Gesser.
3  * Copyright (C) 2011, 2013-2016 The JavaParser Team.
4  *
5  * This file is part of JavaParser.
6  *
7  * JavaParser can be used either under the terms of
8  * a) the GNU Lesser General Public License as published by
9  *     the Free Software Foundation, either version 3 of the License, or
10  *     (at your option) any later version.
11  * b) the terms of the Apache License
12  *
13  * You should have received a copy of both licenses in LICENCE.LGPL and
14  * LICENCE.APACHE. Please refer to those files for details.
15  *
16  * JavaParser is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU Lesser General Public License for more details.
20  */
21 
22 package com.github.javaparser;
23 
24 import com.github.javaparser.ast.Node;
25 import com.github.javaparser.ast.observer.Observable;
26 
27 import java.util.Optional;
28 
29 /**
30  * An object that has a parent node.
31  */
32 public interface HasParentNode<T> extends Observable {
33 
34     /**
35      * Return the parent node or null, if no parent is set.
36      */
getParentNode()37     Optional<Node> getParentNode();
38 
39     /**
40      * Set the parent node.
41      *
42      * @param parentNode the parent node or null, to set no parent
43      * @return return <i>this</i>
44      */
setParentNode(Node parentNode)45     T setParentNode(Node parentNode);
46 
47     /**
48      * <i>this</i> for everything except NodeLists. NodeLists use their parent as their children parent.
49      */
getParentNodeForChildren()50     Node getParentNodeForChildren();
51 
52     /**
53      * Get the ancestor of the node having the given type, or null if no ancestor of the given type is found.
54      */
getAncestorOfType(Class<N> classType)55     default <N> Optional<N> getAncestorOfType(Class<N> classType) {
56         Node parent = getParentNode().orElse(null);
57         while (parent != null) {
58             if (classType.isAssignableFrom(parent.getClass())) {
59                 return Optional.of(classType.cast(parent));
60             }
61             parent = parent.getParentNode().orElse(null);
62         }
63         return Optional.empty();
64     }
65 }
66