1/*
2 * ProGuard -- shrinking, optimization, obfuscation, and preverification
3 *             of Java bytecode.
4 *
5 * Copyright (c) 2002-2009 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 * extend or implement a given class. This exception includes the class itself.
32 *
33 * @author Eric Lafortune
34 */
35public class ImplementedClassConstantFilter
36extends      SimplifiedVisitor
37implements   ConstantVisitor
38{
39    private final Clazz           implementedClass;
40    private final ConstantVisitor constantVisitor;
41
42
43    /**
44     * Creates a new ImplementedClassConstantFilter.
45     * @param implementedClass the class whose implementations will not be
46     *                         visited.
47     * @param constantVisitor  the <code>ConstantVisitor</code> to which visits
48     *                         will be delegated.
49     */
50    public ImplementedClassConstantFilter(Clazz           implementedClass,
51                                          ConstantVisitor constantVisitor)
52    {
53        this.implementedClass = implementedClass;
54        this.constantVisitor  = constantVisitor;
55    }
56
57
58    // Implementations for ConstantVisitor.
59
60    public void visitClassConstant(Clazz clazz, ClassConstant classConstant)
61    {
62        Clazz referencedClass = classConstant.referencedClass;
63        if (referencedClass == null ||
64            !referencedClass.extendsOrImplements(implementedClass))
65        {
66            constantVisitor.visitClassConstant(clazz, classConstant);
67        }
68    }
69}