case-study/jdt-before/core refactoring/org/eclipse/jdt/internal/corext/refactoring/code/TempAssignmentFinder.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2011 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/epl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package org.eclipse.jdt.internal.corext.refactoring.code;
  12
  13 import org.eclipse.jdt.core.dom.ASTNode;
  14 import org.eclipse.jdt.core.dom.ASTVisitor;
  15 import org.eclipse.jdt.core.dom.Assignment;
  16 import org.eclipse.jdt.core.dom.IVariableBinding;
  17 import org.eclipse.jdt.core.dom.Name;
  18 import org.eclipse.jdt.core.dom.PostfixExpression;
  19 import org.eclipse.jdt.core.dom.PrefixExpression;
  20 import org.eclipse.jdt.core.dom.SimpleName;
  21 import org.eclipse.jdt.core.dom.VariableDeclaration;
  22 import org.eclipse.jdt.core.dom.PrefixExpression.Operator;
  23
  24 public class TempAssignmentFinder extends ASTVisitor{
  25         private ASTNode fFirstAssignment;
  26         private IVariableBinding fTempBinding;
  27
  28         TempAssignmentFinder(VariableDeclaration tempDeclaration){
  29                 fTempBinding= tempDeclaration.resolveBinding();
  30         }
  31
  32         private boolean isNameReferenceToTemp(Name name){
  33                 return fTempBinding == name.resolveBinding();
  34         }
  35
  36         private boolean isAssignmentToTemp(Assignment assignment){
  37                 if (fTempBinding == null)
  38                         return false;
  39
  40                 if (! (assignment.getLeftHandSide() instanceof Name))
  41                         return false;
  42                 Name ref= (Name)assignment.getLeftHandSide();
  43                 return isNameReferenceToTemp(ref);
  44         }
  45
  46         boolean hasAssignments(){
  47                 return fFirstAssignment != null;
  48         }
  49
  50         ASTNode getFirstAssignment(){
  51                 return fFirstAssignment;
  52         }
  53
  54         //-- visit methods
  55
  56         @Override
  57         public boolean visit(Assignment assignment) {
  58                 if (! isAssignmentToTemp(assignment))
  59                         return true;
  60
  61                 fFirstAssignment= assignment;
  62                 return false;
  63         }
  64
  65         @Override
  66         public boolean visit(PostfixExpression postfixExpression) {
  67                 if (postfixExpression.getOperand() == null)
  68                         return true;
  69                 if (! (postfixExpression.getOperand() instanceof SimpleName))
  70                         return true;
  71                 SimpleName simpleName= (SimpleName)postfixExpression.getOperand();
  72                 if (! isNameReferenceToTemp(simpleName))
  73                         return true;
  74
  75                 fFirstAssignment= postfixExpression;
  76                 return false;
  77         }
  78
  79         @Override
  80         public boolean visit(PrefixExpression prefixExpression) {
  81                 if (prefixExpression.getOperand() == null)
  82                         return true;
  83                 if (! (prefixExpression.getOperand() instanceof SimpleName))
  84                         return true;
  85                 if (! prefixExpression.getOperator().equals(Operator.DECREMENT) &&
  86                         ! prefixExpression.getOperator().equals(Operator.INCREMENT))
  87                         return true;
  88                 SimpleName simpleName= (SimpleName)prefixExpression.getOperand();
  89                 if (! isNameReferenceToTemp(simpleName))
  90                         return true;
  91
  92                 fFirstAssignment= prefixExpression;
  93                 return false;
  94         }
  95 }