duke@1: /*
jjg@1357:  * Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved.
duke@1:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1:  *
duke@1:  * This code is free software; you can redistribute it and/or modify it
duke@1:  * under the terms of the GNU General Public License version 2 only, as
ohair@554:  * published by the Free Software Foundation.  Oracle designates this
duke@1:  * particular file as subject to the "Classpath" exception as provided
ohair@554:  * by Oracle in the LICENSE file that accompanied this code.
duke@1:  *
duke@1:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@1:  * version 2 for more details (a copy is included in the LICENSE file that
duke@1:  * accompanied this code).
duke@1:  *
duke@1:  * You should have received a copy of the GNU General Public License version
duke@1:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@1:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1:  *
ohair@554:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554:  * or visit www.oracle.com if you need additional information or have any
ohair@554:  * questions.
duke@1:  */
duke@1: 
duke@1: package com.sun.source.util;
duke@1: 
jjg@1357: import java.util.Iterator;
jjg@1357: 
duke@1: import com.sun.source.tree.*;
duke@1: 
duke@1: /**
duke@1:  * A path of tree nodes, typically used to represent the sequence of ancestor
duke@1:  * nodes of a tree node up to the top level CompilationUnitTree node.
duke@1:  *
duke@1:  * @author Jonathan Gibbons
duke@1:  * @since 1.6
duke@1:  */
duke@1: public class TreePath implements Iterable<Tree> {
duke@1:     /**
duke@1:      * Gets a tree path for a tree node within a compilation unit.
duke@1:      * @return null if the node is not found
duke@1:      */
duke@1:     public static TreePath getPath(CompilationUnitTree unit, Tree target) {
duke@1:         return getPath(new TreePath(unit), target);
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * Gets a tree path for a tree node within a subtree identified by a TreePath object.
duke@1:      * @return null if the node is not found
duke@1:      */
duke@1:     public static TreePath getPath(TreePath path, Tree target) {
duke@1:         path.getClass();
duke@1:         target.getClass();
duke@1: 
duke@1:         class Result extends Error {
duke@1:             static final long serialVersionUID = -5942088234594905625L;
duke@1:             TreePath path;
duke@1:             Result(TreePath path) {
duke@1:                 this.path = path;
duke@1:             }
duke@1:         }
jjg@1455: 
duke@1:         class PathFinder extends TreePathScanner<TreePath,Tree> {
duke@1:             public TreePath scan(Tree tree, Tree target) {
jjg@1455:                 if (tree == target) {
duke@1:                     throw new Result(new TreePath(getCurrentPath(), target));
jjg@1455:                 }
duke@1:                 return super.scan(tree, target);
duke@1:             }
duke@1:         }
duke@1: 
jjg@1455:         if (path.getLeaf() == target) {
jjg@1455:             return path;
jjg@1455:         }
jjg@1455: 
duke@1:         try {
duke@1:             new PathFinder().scan(path, target);
duke@1:         } catch (Result result) {
duke@1:             return result.path;
duke@1:         }
duke@1:         return null;
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * Creates a TreePath for a root node.
duke@1:      */
duke@1:     public TreePath(CompilationUnitTree t) {
duke@1:         this(null, t);
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * Creates a TreePath for a child node.
duke@1:      */
duke@1:     public TreePath(TreePath p, Tree t) {
duke@1:         if (t.getKind() == Tree.Kind.COMPILATION_UNIT) {
duke@1:             compilationUnit = (CompilationUnitTree) t;
duke@1:             parent = null;
duke@1:         }
duke@1:         else {
duke@1:             compilationUnit = p.compilationUnit;
duke@1:             parent = p;
duke@1:         }
duke@1:         leaf = t;
duke@1:     }
duke@1:     /**
duke@1:      * Get the compilation unit associated with this path.
duke@1:      */
duke@1:     public CompilationUnitTree getCompilationUnit() {
duke@1:         return compilationUnit;
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * Get the leaf node for this path.
duke@1:      */
duke@1:     public Tree getLeaf() {
duke@1:         return leaf;
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * Get the path for the enclosing node, or null if there is no enclosing node.
duke@1:      */
duke@1:     public TreePath getParentPath() {
duke@1:         return parent;
duke@1:     }
duke@1: 
duke@1:     public Iterator<Tree> iterator() {
duke@1:         return new Iterator<Tree>() {
duke@1:             public boolean hasNext() {
jjg@308:                 return next != null;
duke@1:             }
duke@1: 
duke@1:             public Tree next() {
jjg@308:                 Tree t = next.leaf;
jjg@308:                 next = next.parent;
jjg@308:                 return t;
duke@1:             }
duke@1: 
duke@1:             public void remove() {
duke@1:                 throw new UnsupportedOperationException();
duke@1:             }
duke@1: 
jjg@308:             private TreePath next = TreePath.this;
duke@1:         };
duke@1:     }
duke@1: 
duke@1:     private CompilationUnitTree compilationUnit;
duke@1:     private Tree leaf;
duke@1:     private TreePath parent;
duke@1: }