Home | History | Annotate | Download | only in annotation 
      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.attribute.annotation;
     22 
     23 import proguard.classfile.*;
     24 import proguard.classfile.attribute.annotation.visitor.ElementValueVisitor;
     25 import proguard.classfile.visitor.MemberVisitor;
     26 
     27 /**
     28  * This abstract class represents an element value that is attached to an
     29  * annotation or an annotation default. Specific types of element values are
     30  * subclassed from it.
     31  *
     32  * @author Eric Lafortune
     33  */
     34 public abstract class ElementValue implements VisitorAccepter
     35 {
     36     /**
     37      * An extra field for the optional element name. It is used in element value
     38      * pairs of annotations. Otherwise, it is 0.
     39      */
     40     public int u2elementNameIndex;
     41 
     42     /**
     43      * An extra field pointing to the referenced <code>Clazz</code>
     44      * object, if applicable. This field is typically filled out by the
     45      * <code>{@link proguard.classfile.util.ClassReferenceInitializer}</code>.
     46      */
     47     public Clazz referencedClass;
     48 
     49     /**
     50      * An extra field pointing to the referenced <code>Method</code>
     51      * object, if applicable. This field is typically filled out by the
     52      * <code>{@link proguard.classfile.util.ClassReferenceInitializer}</code>.
     53      */
     54     public Method referencedMethod;
     55 
     56     /**
     57      * An extra field in which visitors can store information.
     58      */
     59     public Object visitorInfo;
     60 
     61 
     62     /**
     63      * Creates an uninitialized ElementValue.
     64      */
     65     protected ElementValue()
     66     {
     67     }
     68 
     69 
     70     /**
     71      * Creates an initialized ElementValue.
     72      */
     73     protected ElementValue(int u2elementNameIndex)
     74     {
     75         this.u2elementNameIndex = u2elementNameIndex;
     76     }
     77 
     78 
     79     /**
     80      * Returns the element name.
     81      */
     82     public String getMethodName(Clazz clazz)
     83     {
     84         return clazz.getString(u2elementNameIndex);
     85     }
     86 
     87 
     88     // Abstract methods to be implemented by extensions.
     89 
     90     /**
     91      * Returns the tag of this element value.
     92      */
     93     public abstract int getTag();
     94 
     95 
     96     /**
     97      * Accepts the given visitor.
     98      */
     99     public abstract void accept(Clazz clazz, Annotation annotation, ElementValueVisitor elementValueVisitor);
    100 
    101 
    102 
    103     /**
    104      * Applies the given visitor to the referenced method.
    105      */
    106     public void referencedMethodAccept(MemberVisitor memberVisitor)
    107     {
    108         if (referencedMethod != null)
    109         {
    110             referencedMethod.accept(referencedClass, memberVisitor);
    111         }
    112     }
    113 
    114 
    115     // Implementations for VisitorAccepter.
    116 
    117     public Object getVisitorInfo()
    118     {
    119         return visitorInfo;
    120     }
    121 
    122     public void setVisitorInfo(Object visitorInfo)
    123     {
    124         this.visitorInfo = visitorInfo;
    125     }
    126 }
    127