001 /*
002 * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package com.sun.source.util;
027
028 import com.sun.source.tree.*;
029 import java.util.Iterator;
030
031 /**
032 * A path of tree nodes, typically used to represent the sequence of ancestor
033 * nodes of a tree node up to the top level CompilationUnitTree node.
034 *
035 * @author Jonathan Gibbons
036 * @since 1.6
037 */
038 public class TreePath implements Iterable<Tree> {
039 /**
040 * Gets a tree path for a tree node within a compilation unit.
041 * @return null if the node is not found
042 */
043 public static TreePath getPath(CompilationUnitTree unit, Tree target) {
044 return getPath(new TreePath(unit), target);
045 }
046
047 /**
048 * Gets a tree path for a tree node within a subtree identified by a TreePath object.
049 * @return null if the node is not found
050 */
051 public static TreePath getPath(TreePath path, Tree target) {
052 path.getClass();
053 target.getClass();
054
055 class Result extends Error {
056 static final long serialVersionUID = -5942088234594905625L;
057 TreePath path;
058 Result(TreePath path) {
059 this.path = path;
060 }
061 }
062 class PathFinder extends TreePathScanner<TreePath,Tree> {
063 public TreePath scan(Tree tree, Tree target) {
064 if (tree == target)
065 throw new Result(new TreePath(getCurrentPath(), target));
066 return super.scan(tree, target);
067 }
068 }
069
070 try {
071 new PathFinder().scan(path, target);
072 } catch (Result result) {
073 return result.path;
074 }
075 return null;
076 }
077
078 /**
079 * Creates a TreePath for a root node.
080 */
081 public TreePath(CompilationUnitTree t) {
082 this(null, t);
083 }
084
085 /**
086 * Creates a TreePath for a child node.
087 */
088 public TreePath(TreePath p, Tree t) {
089 if (t.getKind() == Tree.Kind.COMPILATION_UNIT) {
090 compilationUnit = (CompilationUnitTree) t;
091 parent = null;
092 }
093 else {
094 compilationUnit = p.compilationUnit;
095 parent = p;
096 }
097 leaf = t;
098 }
099 /**
100 * Get the compilation unit associated with this path.
101 */
102 public CompilationUnitTree getCompilationUnit() {
103 return compilationUnit;
104 }
105
106 /**
107 * Get the leaf node for this path.
108 */
109 public Tree getLeaf() {
110 return leaf;
111 }
112
113 /**
114 * Get the path for the enclosing node, or null if there is no enclosing node.
115 */
116 public TreePath getParentPath() {
117 return parent;
118 }
119
120 public Iterator<Tree> iterator() {
121 return new Iterator<Tree>() {
122 public boolean hasNext() {
123 return curr.parent != null;
124 }
125
126 public Tree next() {
127 curr = curr.parent;
128 return curr.leaf;
129 }
130
131 public void remove() {
132 throw new UnsupportedOperationException();
133 }
134
135 private TreePath curr;
136 };
137 }
138
139 private CompilationUnitTree compilationUnit;
140 private Tree leaf;
141 private TreePath parent;
142 }