content: /*
   * [The "BSD licence"]
   * Copyright (c) 2010 Ben Gruver (JesusFreke)
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. The name of the author may not be used to endorse or promote products
   *    derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package org.jf.dexlib.Code;
  
  import org.jf.dexlib.*;
  import org.jf.dexlib.Util.NumberUtils;
  
  public abstract class InstructionWithReference extends Instruction {
      private Item referencedItem;
  
      protected InstructionWithReference(Opcode opcode, Item referencedItem) {
          super(opcode);
          this.referencedItem = referencedItem;
          checkReferenceType();
      }
  
      protected InstructionWithReference(DexFile dexFile, Opcode opcode, byte[] buffer, int bufferIndex) {
          super(opcode);
  
          int itemIndex = getReferencedItemIndex(buffer, bufferIndex); 
          lookupReferencedItem(dexFile, opcode, itemIndex);
      }
  
      protected int getReferencedItemIndex(byte[] buffer, int bufferIndex) {
          return NumberUtils.decodeUnsignedShort(buffer, bufferIndex + 2);
      }
  
      public Item getReferencedItem() {
          return referencedItem;
      }
  
  
      public void setReferencedItem(Item referencedItem) {
          this.referencedItem=referencedItem;
      }
  
  
      private void lookupReferencedItem(DexFile dexFile, Opcode opcode, int itemIndex) {
          switch (opcode.referenceType) {
              case field:
                  referencedItem = dexFile.FieldIdsSection.getItemByIndex(itemIndex);
                  return;
              case method:
                  referencedItem = dexFile.MethodIdsSection.getItemByIndex(itemIndex);
                  return;
              case type:
                  referencedItem = dexFile.TypeIdsSection.getItemByIndex(itemIndex);
                  return;
              case string:
                  referencedItem = dexFile.StringIdsSection.getItemByIndex(itemIndex);
          }
      }
  
  
      private void checkReferenceType() {
          switch (opcode.referenceType) {
              case field:
                  if (!(referencedItem instanceof FieldIdItem)) {
                      throw new RuntimeException(referencedItem.getClass().getSimpleName() +
                              " is the wrong item type for opcode " + opcode.name + ". Expecting FieldIdItem.");
                  }
                  return;
              case method:
                  if (!(referencedItem instanceof MethodIdItem)) {
                      throw new RuntimeException(referencedItem.getClass().getSimpleName() +
                              " is the wrong item type for opcode " + opcode.name + ". Expecting MethodIdItem.");
                  }
                  return;
              case type:
                  if (!(referencedItem instanceof TypeIdItem)) {
                      throw new RuntimeException(referencedItem.getClass().getSimpleName() +
                              " is the wrong item type for opcode " + opcode.name + ". Expecting TypeIdItem.");
                  }
                  return;
              case string:
                  if (!(referencedItem instanceof StringIdItem)) {
                      throw new RuntimeException(referencedItem.getClass().getSimpleName() +
                              " is the wrong item type for opcode " + opcode.name + ". Expecting StringIdItem.");
                  }
                  return;
              default:
                  if (referencedItem != null) {
                      throw new RuntimeException(referencedItem.getClass().getSimpleName() +
                              " is invalid for opcode " + opcode.name + ". This opcode does not reference an item");
                  }
          }
      }
  }
  