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      1 /*
      2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
      3  *             of Java bytecode.
      4  *
      5  * Copyright (c) 2002-2009 Eric Lafortune (eric (at) 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  * optionally travel to the visited class, its superclass, its interfaces, and
     29  * its subclasses.
     30  *
     31  * @author Eric Lafortune
     32  */
     33 public class ClassHierarchyTraveler implements ClassVisitor
     34 {
     35     private final boolean visitThisClass;
     36     private final boolean visitSuperClass;
     37     private final boolean visitInterfaces;
     38     private final boolean visitSubclasses;
     39 
     40     private final ClassVisitor classVisitor;
     41 
     42 
     43     /**
     44      * Creates a new ClassHierarchyTraveler.
     45      * @param visitThisClass  specifies whether to visit the originally visited
     46      *                        classes.
     47      * @param visitSuperClass specifies whether to visit the super classes of
     48      *                        the visited classes.
     49      * @param visitInterfaces specifies whether to visit the interfaces of
     50      *                        the visited classes.
     51      * @param visitSubclasses specifies whether to visit the subclasses of
     52      *                        the visited classes.
     53      * @param classVisitor    the <code>ClassVisitor</code> to
     54      *                        which visits will be delegated.
     55      */
     56     public ClassHierarchyTraveler(boolean      visitThisClass,
     57                                   boolean      visitSuperClass,
     58                                   boolean      visitInterfaces,
     59                                   boolean      visitSubclasses,
     60                                   ClassVisitor classVisitor)
     61     {
     62         this.visitThisClass  = visitThisClass;
     63         this.visitSuperClass = visitSuperClass;
     64         this.visitInterfaces = visitInterfaces;
     65         this.visitSubclasses = visitSubclasses;
     66 
     67         this.classVisitor = classVisitor;
     68     }
     69 
     70 
     71     // Implementations for ClassVisitor.
     72 
     73     public void visitProgramClass(ProgramClass programClass)
     74     {
     75         programClass.hierarchyAccept(visitThisClass,
     76                                      visitSuperClass,
     77                                      visitInterfaces,
     78                                      visitSubclasses,
     79                                      classVisitor);
     80     }
     81 
     82 
     83     public void visitLibraryClass(LibraryClass libraryClass)
     84     {
     85         libraryClass.hierarchyAccept(visitThisClass,
     86                                      visitSuperClass,
     87                                      visitInterfaces,
     88                                      visitSubclasses,
     89                                      classVisitor);
     90     }
     91 }
     92