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Java > Open Source Codes > proguard > classfile > visitor > ConcreteClassDownTraveler


1 /*
2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
3  * of Java bytecode.
4  *
5  * Copyright (c) 2002-2007 Eric Lafortune (eric@graphics.cornell.edu)
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the Free
9  * Software Foundation; either version 2 of the License, or (at your option)
10  * any later version.
11  *
12  * This program is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15  * more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with this program; if not, write to the Free Software Foundation, Inc.,
19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20  */
21 package proguard.classfile.visitor;
22
23 import proguard.classfile.*;
24
25
26 /**
27  * This <code>ClassVisitor</code> lets a given <code>ClassVisitor</code>
28  * travel to the first concrete subclasses down in its hierarchy of abstract
29  * classes and concrete classes.
30  *
31  * @author Eric Lafortune
32  */
33 public class ConcreteClassDownTraveler
34 implements ClassVisitor
35 {
36     private ClassVisitor classVisitor;
37
38
39     /**
40      * Creates a new ConcreteClassDownTraveler.
41      * @param classVisitor the <code>ClassVisitor</code> to
42      * which visits will be delegated.
43      */
44     public ConcreteClassDownTraveler(ClassVisitor classVisitor)
45     {
46         this.classVisitor = classVisitor;
47     }
48
49
50     // Implementations for ClassVisitor.
51
52     public void visitProgramClass(ProgramClass programClass)
53     {
54         // Is this an abstract class or an interface?
55 if ((programClass.getAccessFlags() &
56              (ClassConstants.INTERNAL_ACC_INTERFACE |
57               ClassConstants.INTERNAL_ACC_ABSTRACT)) != 0)
58         {
59             // Travel down the hierarchy.
60 Clazz[] subClasses = programClass.subClasses;
61             if (subClasses != null)
62             {
63                 for (int index = 0; index < subClasses.length; index++)
64                 {
65                     subClasses[index].accept(this);
66                 }
67             }
68         }
69         else
70         {
71             // Visit the class. Don't descend any further.
72 programClass.accept(classVisitor);
73         }
74     }
75
76
77     public void visitLibraryClass(LibraryClass libraryClass)
78     {
79         // Is this an abstract class or interface?
80 if ((libraryClass.getAccessFlags() &
81              (ClassConstants.INTERNAL_ACC_INTERFACE |
82               ClassConstants.INTERNAL_ACC_ABSTRACT)) != 0)
83         {
84             // Travel down the hierarchy.
85 Clazz[] subClasses = libraryClass.subClasses;
86             if (subClasses != null)
87             {
88                 for (int index = 0; index < subClasses.length; index++)
89                 {
90                     subClasses[index].accept(this);
91                 }
92             }
93         }
94         else
95         {
96             // Visit the class. Don't descend any further.
97 libraryClass.accept(classVisitor);
98         }
99     }
100 }
101
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