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      1 /*
      2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
      3  *             of Java bytecode.
      4  *
      5  * Copyright (c) 2002-2014 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 import proguard.util.*;
     25 
     26 
     27 /**
     28  * This <code>MemberVisitor</code> delegates its visits to another given
     29  * <code>MemberVisitor</code>, but only when the visited member
     30  * has a descriptor that matches a given regular expression.
     31  *
     32  * @author Eric Lafortune
     33  */
     34 public class MemberDescriptorFilter implements MemberVisitor
     35 {
     36     private final StringMatcher regularExpressionMatcher;
     37     private final MemberVisitor memberVisitor;
     38 
     39 
     40     /**
     41      * Creates a new MemberDescriptorFilter.
     42      * @param regularExpression the regular expression against which member
     43      *                          descriptors will be matched.
     44      * @param memberVisitor     the <code>MemberVisitor</code> to which visits
     45      *                          will be delegated.
     46      */
     47     public MemberDescriptorFilter(String        regularExpression,
     48                                   MemberVisitor memberVisitor)
     49     {
     50         this(new ClassNameParser().parse(regularExpression), memberVisitor);
     51     }
     52 
     53 
     54     /**
     55      * Creates a new MemberDescriptorFilter.
     56      * @param regularExpressionMatcher the regular expression against which
     57      *                                 member descriptors will be matched.
     58      * @param memberVisitor            the <code>MemberVisitor</code> to which
     59      *                                 visits will be delegated.
     60      */
     61     public MemberDescriptorFilter(StringMatcher regularExpressionMatcher,
     62                                   MemberVisitor memberVisitor)
     63     {
     64         this.regularExpressionMatcher = regularExpressionMatcher;
     65         this.memberVisitor            = memberVisitor;
     66     }
     67 
     68 
     69     // Implementations for MemberVisitor.
     70 
     71     public void visitProgramField(ProgramClass programClass, ProgramField programField)
     72     {
     73         if (accepted(programField.getDescriptor(programClass)))
     74         {
     75             memberVisitor.visitProgramField(programClass, programField);
     76         }
     77     }
     78 
     79 
     80     public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)
     81     {
     82         if (accepted(programMethod.getDescriptor(programClass)))
     83         {
     84             memberVisitor.visitProgramMethod(programClass, programMethod);
     85         }
     86     }
     87 
     88 
     89     public void visitLibraryField(LibraryClass libraryClass, LibraryField libraryField)
     90     {
     91         if (accepted(libraryField.getDescriptor(libraryClass)))
     92         {
     93             memberVisitor.visitLibraryField(libraryClass, libraryField);
     94         }
     95     }
     96 
     97 
     98     public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod)
     99     {
    100         if (accepted(libraryMethod.getDescriptor(libraryClass)))
    101         {
    102             memberVisitor.visitLibraryMethod(libraryClass, libraryMethod);
    103         }
    104     }
    105 
    106 
    107     // Small utility methods.
    108 
    109     private boolean accepted(String name)
    110     {
    111         return regularExpressionMatcher.matches(name);
    112     }
    113 }
    114