| 1 | /* |
|---|---|
| 2 | * Copyright (C) 2007-2010 Júlio Vilmar Gesser. |
| 3 | * Copyright (C) 2011, 2013-2020 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 | import java.util.function.Predicate; |
| 29 | |
| 30 | /** |
| 31 | * An object that can have a parent node. |
| 32 | */ |
| 33 | public interface HasParentNode<T> extends Observable { |
| 34 | |
| 35 | /** |
| 36 | * Returns the parent node, or {@code Optional.empty} if no parent is set. |
| 37 | */ |
| 38 | Optional<Node> getParentNode(); |
| 39 | |
| 40 | /** |
| 41 | * Sets the parent node. |
| 42 | * |
| 43 | * @param parentNode the parent node, or {@code null} to set no parent. |
| 44 | * @return return {@code this} |
| 45 | */ |
| 46 | T setParentNode(Node parentNode); |
| 47 | |
| 48 | /** |
| 49 | * Returns the parent node from the perspective of the children of this node. |
| 50 | * <p> |
| 51 | * That is, this method returns {@code this} for everything except {@code NodeList}. A {@code NodeList} returns its |
| 52 | * parent node instead. This is because a {@code NodeList} sets the parent of all its children to its own parent |
| 53 | * node (see {@link com.github.javaparser.ast.NodeList} for details). |
| 54 | */ |
| 55 | Node getParentNodeForChildren(); |
| 56 | |
| 57 | /** |
| 58 | * Walks the parents of this node and returns the first node of type {@code type}, or {@code empty()} if none is |
| 59 | * found. The given type may also be an interface type, such as one of the {@code NodeWith...} interface types. |
| 60 | */ |
| 61 | default <N> Optional<N> findAncestor(Class<N> type) { |
| 62 | return findAncestor(type, x -> true); |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Walks the parents of this node and returns the first node of type {@code type} that matches {@code predicate}, or |
| 67 | * {@code empty()} if none is found. The given type may also be an interface type, such as one of the |
| 68 | * {@code NodeWith...} interface types. |
| 69 | */ |
| 70 | default <N> Optional<N> findAncestor(Class<N> type, Predicate<N> predicate) { |
| 71 | Optional<Node> possibleParent = getParentNode(); |
| 72 | while (possibleParent.isPresent()) { |
| 73 | Node parent = possibleParent.get(); |
| 74 | if (type.isAssignableFrom(parent.getClass()) && predicate.test(type.cast(parent))) { |
| 75 | return Optional.of(type.cast(parent)); |
| 76 | } |
| 77 | possibleParent = parent.getParentNode(); |
| 78 | } |
| 79 | return Optional.empty(); |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Determines whether this {@code HasParentNode} node is a descendant of the given node. A node is <i>not</i> a |
| 84 | * descendant of itself. |
| 85 | * |
| 86 | * @param ancestor the node for which to determine whether it has this node as an ancestor. |
| 87 | * @return {@code true} if this node is a descendant of the given node, and {@code false} otherwise. |
| 88 | * @see Node#isAncestorOf(Node) |
| 89 | */ |
| 90 | default boolean isDescendantOf(Node ancestor) { |
| 91 | return findAncestor(Node.class, n -> n == ancestor).isPresent(); |
| 92 | } |
| 93 | |
| 94 | } |
| 95 |
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