gomp-20050608-branch/libjava/classpath/gnu/java/beans/decoder/IndexContext.java

   1 /* gnu.java.beans.decoder.IndexContext
   2    Copyright (C) 2004 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package gnu.java.beans.decoder;
  39
  40 /** IndexContext is Context implementation that senses whether it is an indexed get or set
  41  * operation and invokes this operation.
  42  *
  43  * <p>An IndexContent is a get operation when no argument is provided and a set operation if one
  44  * argument is provided.</p>
  45  *
  46  * @author Robert Schuster
  47  */
  48 class IndexContext extends AbstractContext
  49 {
  50   private Object result;
  51   private Object argument;
  52   private int index;
  53   private boolean isSetter;
  54
  55   IndexContext(String id, int newIndex)
  56   {
  57     setId(id);
  58     index = newIndex;
  59   }
  60
  61   /* (non-Javadoc)
  62    * @see gnu.java.beans.decoder.Context#addObject(java.lang.Object)
  63    */
  64   public void addParameterObject(Object o) throws AssemblyException
  65   {
  66     if (! isSetter)
  67       {
  68         argument = o;
  69         isSetter = true;
  70       }
  71     else
  72       throw new AssemblyException(new IllegalStateException("More than one argument for indiced access is not possible."));
  73   }
  74
  75   /* (non-Javadoc)
  76    * @see gnu.java.beans.decoder.Context#reportStatement()
  77    */
  78   public void notifyStatement(Context outerContext) throws AssemblyException
  79   {
  80     throw new AssemblyException(new IllegalStateException("Statements inside indiced access are not allowed."));
  81   }
  82
  83   /* (non-Javadoc)
  84    * @see gnu.java.beans.decoder.Context#endContext(gnu.java.beans.decoder.Context)
  85    */
  86   public Object endContext(Context outerContext) throws AssemblyException
  87   {
  88     if (isSetter)
  89       {
  90         // setter
  91         outerContext.set(index, argument);
  92
  93         return null;
  94       }
  95     else
  96       // getter
  97       return result = outerContext.get(index);
  98   }
  99
 100   /* (non-Javadoc)
 101    * @see gnu.java.beans.decoder.Context#subContextFailed()
 102    */
 103   public boolean subContextFailed()
 104   {
 105     // returns true to indicate that indiced access assembly fails when one of its
 106     // argument could not be assembled
 107     return true;
 108   }
 109
 110   /* (non-Javadoc)
 111    * @see gnu.java.beans.decoder.Context#set(int, java.lang.Object)
 112    */
 113   public void set(int index, Object o) throws AssemblyException
 114   {
 115     throw new AssemblyException(new IllegalStateException("Setter is not allowed inside indiced access."));
 116   }
 117
 118   /* (non-Javadoc)
 119    * @see gnu.java.beans.decoder.Context#get(int)
 120    */
 121   public Object get(int index) throws AssemblyException
 122   {
 123     throw new AssemblyException(new IllegalStateException("getter is not allowed insided indiced access."));
 124   }
 125
 126   public Object getResult()
 127   {
 128     return result;
 129   }
 130 }