1 /*

     2  * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any questions.

    24  */

    25 

    26 package com.sun.source.util;

    27 

    28 import com.sun.source.tree.*;

    29 import java.util.Iterator;

    30 

    31 /**

    32  * A path of tree nodes, typically used to represent the sequence of ancestor

    33  * nodes of a tree node up to the top level CompilationUnitTree node.

    34  *

    35  * @author Jonathan Gibbons

    36  * @since 1.6

    37  */

    38 public class TreePath implements Iterable<Tree> {

    39     /**

    40      * Gets a tree path for a tree node within a compilation unit.

    41      * @return null if the node is not found

    42      */

    43     public static TreePath getPath(CompilationUnitTree unit, Tree target) {

    44         return getPath(new TreePath(unit), target);

    45     }

    46 

    47     /**

    48      * Gets a tree path for a tree node within a subtree identified by a TreePath object.

    49      * @return null if the node is not found

    50      */

    51     public static TreePath getPath(TreePath path, Tree target) {

    52         path.getClass();

    53         target.getClass();

    54 

    55         class Result extends Error {

    56             static final long serialVersionUID = -5942088234594905625L;

    57             TreePath path;

    58             Result(TreePath path) {

    59                 this.path = path;

    60             }

    61         }

    62         class PathFinder extends TreePathScanner<TreePath,Tree> {

    63             public TreePath scan(Tree tree, Tree target) {

    64                 if (tree == target)

    65                     throw new Result(new TreePath(getCurrentPath(), target));

    66                 return super.scan(tree, target);

    67             }

    68         }

    69 

    70         try {

    71             new PathFinder().scan(path, target);

    72         } catch (Result result) {

    73             return result.path;

    74         }

    75         return null;

    76     }

    77 

    78     /**

    79      * Creates a TreePath for a root node.

    80      */

    81     public TreePath(CompilationUnitTree t) {

    82         this(null, t);

    83     }

    84 

    85     /**

    86      * Creates a TreePath for a child node.

    87      */

    88     public TreePath(TreePath p, Tree t) {

    89         if (t.getKind() == Tree.Kind.COMPILATION_UNIT) {

    90             compilationUnit = (CompilationUnitTree) t;

    91             parent = null;

    92         }

    93         else {

    94             compilationUnit = p.compilationUnit;

    95             parent = p;

    96         }

    97         leaf = t;

    98     }

    99     /**

   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 }