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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.util;
     22 
     23 import proguard.classfile.ClassConstants;
     24 
     25 
     26 /**
     27  * An <code>ExternalTypeEnumeration</code> provides an enumeration of all
     28  * types listed in a given external descriptor string. The method name can
     29  * be retrieved separately.
     30  * <p>
     31  * A <code>ExternalTypeEnumeration</code> object can be reused for processing
     32  * different subsequent descriptors, by means of the <code>setDescriptor</code>
     33  * method.
     34  *
     35  * @author Eric Lafortune
     36  */
     37 public class ExternalTypeEnumeration
     38 {
     39     private String descriptor;
     40     private int    index;
     41 
     42 
     43     public ExternalTypeEnumeration(String descriptor)
     44     {
     45         setDescriptor(descriptor);
     46     }
     47 
     48 
     49     ExternalTypeEnumeration()
     50     {
     51     }
     52 
     53 
     54     void setDescriptor(String descriptor)
     55     {
     56         this.descriptor = descriptor;
     57 
     58         reset();
     59     }
     60 
     61 
     62     public void reset()
     63     {
     64         index = descriptor.indexOf(ClassConstants.EXTERNAL_METHOD_ARGUMENTS_OPEN) + 1;
     65 
     66         if (index < 1)
     67         {
     68             throw new IllegalArgumentException("Missing opening parenthesis in descriptor ["+descriptor+"]");
     69         }
     70     }
     71 
     72 
     73     public boolean hasMoreTypes()
     74     {
     75         return index < descriptor.length() - 1;
     76     }
     77 
     78 
     79     public String nextType()
     80     {
     81         int startIndex = index;
     82 
     83         // Find the next separating comma.
     84         index = descriptor.indexOf(ClassConstants.EXTERNAL_METHOD_ARGUMENTS_SEPARATOR,
     85                                    startIndex);
     86 
     87         // Otherwise find the closing parenthesis.
     88         if (index < 0)
     89         {
     90             index = descriptor.indexOf(ClassConstants.EXTERNAL_METHOD_ARGUMENTS_CLOSE,
     91                                        startIndex);
     92             if (index < 0)
     93             {
     94                 throw new IllegalArgumentException("Missing closing parenthesis in descriptor ["+descriptor+"]");
     95             }
     96         }
     97 
     98         return descriptor.substring(startIndex, index++).trim();
     99     }
    100 
    101 
    102     public String methodName()
    103     {
    104         return descriptor.substring(0, descriptor.indexOf(ClassConstants.EXTERNAL_METHOD_ARGUMENTS_OPEN)).trim();
    105     }
    106 }
    107