ImplementingClassConstantFilter.java revision b9cc48a43ed984587c939d02fba5316bf5c0df6e 
1/*
2 * ProGuard -- shrinking, optimization, obfuscation, and preverification
3 *             of Java bytecode.
4 *
5 * Copyright (c) 2002-2013 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 */
21package proguard.classfile.visitor;
22
23import proguard.classfile.*;
24import proguard.classfile.constant.visitor.ConstantVisitor;
25import proguard.classfile.constant.ClassConstant;
26import proguard.classfile.util.SimplifiedVisitor;
27
28/**
29 * This <code>ConstantVisitor</code> delegates its visits to class constants
30 * to another given <code>ConstantVisitor</code>, except for classes that
31 * are extended or implemented by a given class. This exception includes the
32 * class itself.
33 *
34 * @author Eric Lafortune
35 */
36public class ImplementingClassConstantFilter
37extends      SimplifiedVisitor
38implements   ConstantVisitor
39{
40    private final Clazz           implementingClass;
41    private final ConstantVisitor constantVisitor;
42
43
44    /**
45     * Creates a new ImplementingClassConstantFilter.
46     * @param implementingClass the class whose superclasses and interfaces will
47     *                          not be visited.
48     * @param constantVisitor   the <code>ConstantVisitor</code> to which visits
49     *                          will be delegated.
50     */
51    public ImplementingClassConstantFilter(Clazz           implementingClass,
52                                           ConstantVisitor constantVisitor)
53    {
54        this.implementingClass = implementingClass;
55        this.constantVisitor   = constantVisitor;
56    }
57
58
59    // Implementations for ConstantVisitor.
60
61    public void visitClassConstant(Clazz clazz, ClassConstant classConstant)
62    {
63        Clazz referencedClass = classConstant.referencedClass;
64        if (referencedClass == null ||
65            !implementingClass.extendsOrImplements(referencedClass))
66        {
67            constantVisitor.visitClassConstant(clazz, classConstant);
68        }
69    }
70}