1/*
2 * ProGuard -- shrinking, optimization, obfuscation, and preverification
3 *             of Java bytecode.
4 *
5 * Copyright (c) 2002-2014 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.*;
24
25
26/**
27 * This <code>ClassVisitor</code>     delegates its visits to another given
28 * <code>ClassVisitor</code>, but only when the visited class
29 * has the proper access flags.
30 *
31 * @see ClassConstants
32 *
33 * @author Eric Lafortune
34 */
35public class ClassAccessFilter implements ClassVisitor
36{
37    private final int          requiredSetAccessFlags;
38    private final int          requiredUnsetAccessFlags;
39    private final ClassVisitor classVisitor;
40
41
42    /**
43     * Creates a new ClassAccessFilter.
44     * @param requiredSetAccessFlags   the class access flags that should be
45     *                                 set.
46     * @param requiredUnsetAccessFlags the class access flags that should be
47     *                                 unset.
48     * @param classVisitor             the <code>ClassVisitor</code> to
49     *                                 which visits will be delegated.
50     */
51    public ClassAccessFilter(int          requiredSetAccessFlags,
52                             int          requiredUnsetAccessFlags,
53                             ClassVisitor classVisitor)
54    {
55        this.requiredSetAccessFlags   = requiredSetAccessFlags;
56        this.requiredUnsetAccessFlags = requiredUnsetAccessFlags;
57        this.classVisitor             = classVisitor;
58    }
59
60
61    // Implementations for ClassVisitor.
62
63    public void visitProgramClass(ProgramClass programClass)
64    {
65        if (accepted(programClass.getAccessFlags()))
66        {
67            classVisitor.visitProgramClass(programClass);
68        }
69    }
70
71
72    public void visitLibraryClass(LibraryClass libraryClass)
73    {
74        if (accepted(libraryClass.getAccessFlags()))
75        {
76            classVisitor.visitLibraryClass(libraryClass);
77        }
78    }
79
80
81    // Small utility methods.
82
83    private boolean accepted(int accessFlags)
84    {
85        return (requiredSetAccessFlags   & ~accessFlags) == 0 &&
86               (requiredUnsetAccessFlags &  accessFlags) == 0;
87    }
88}
89