01: /*
02: * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
03: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
04: *
05: * This code is free software; you can redistribute it and/or modify it
06: * under the terms of the GNU General Public License version 2 only, as
07: * published by the Free Software Foundation. Sun designates this
08: * particular file as subject to the "Classpath" exception as provided
09: * 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:
30: /**
31: * A TreeVisitor that visits all the child tree nodes, and provides
32: * support for maintaining a path for the parent nodes.
33: * To visit nodes of a particular type, just override the
34: * corresponding visitorXYZ method.
35: * Inside your method, call super.visitXYZ to visit descendant
36: * nodes.
37: *
38: * @author Jonathan Gibbons
39: * @since 1.6
40: */
41: public class TreePathScanner<R, P> extends TreeScanner<R, P> {
42:
43: /**
44: * Scan a tree from a position identified by a TreePath.
45: */
46: public R scan(TreePath path, P p) {
47: this .path = path;
48: try {
49: return path.getLeaf().accept(this , p);
50: } finally {
51: this .path = null;
52: }
53: }
54:
55: /**
56: * Scan a single node.
57: * The current path is updated for the duration of the scan.
58: */
59: @Override
60: public R scan(Tree tree, P p) {
61: if (tree == null)
62: return null;
63:
64: TreePath prev = path;
65: path = new TreePath(path, tree);
66: try {
67: return tree.accept(this , p);
68: } finally {
69: path = prev;
70: }
71: }
72:
73: /**
74: * Get the current path for the node, as built up by the currently
75: * active set of scan calls.
76: */
77: public TreePath getCurrentPath() {
78: return path;
79: }
80:
81: private TreePath path;
82: }
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