java/java-impl/src/com/intellij/codeInsight/template/ExpressionUtil.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package com.intellij.codeInsight.template;
  17
  18  import com.intellij.openapi.components.ServiceManager;
  19  import com.intellij.openapi.diagnostic.Logger;
  20  import com.intellij.openapi.project.Project;
  21  import com.intellij.openapi.application.ApplicationManager;
  22  import com.intellij.psi.*;
  23  import com.intellij.psi.codeStyle.JavaCodeStyleManager;
  24  import com.intellij.psi.codeStyle.SuggestedNameInfo;
  25  import com.intellij.psi.codeStyle.VariableKind;
  26  import com.intellij.psi.text.BlockSupport;
  27  import com.intellij.util.IncorrectOperationException;
  28  import org.jetbrains.annotations.Nullable;
  29
  30  /**
  31   * @author mike
  32   */
  33  public class ExpressionUtil {
  34    private static final Logger LOG = Logger.getInstance("#com.intellij.codeInsight.template.ExpressionUtil");
  35
  36    private ExpressionUtil() {
  37    }
  38
  39    @Nullable
  40    public static String[] getNames(final ExpressionContext context) {
  41      final Project project = context.getProject();
  42      final int offset = context.getStartOffset();
  43
  44      PsiDocumentManager.getInstance(project).commitAllDocuments();
  45
  46      String[] names = null;
  47      PsiFile file = PsiDocumentManager.getInstance(project).getPsiFile(context.getEditor().getDocument());
  48      PsiElement element = file.findElementAt(offset);
  49      if (element instanceof PsiIdentifier){
  50        names = getNamesForIdentifier(project, (PsiIdentifier)element);
  51      }
  52      else{
  53        final PsiFile fileCopy = (PsiFile)file.copy();
  54        ApplicationManager.getApplication().runWriteAction(new Runnable() {
  55          public void run() {
  56            BlockSupport blockSupport = ServiceManager.getService(project, BlockSupport.class);
  57            try{
  58              blockSupport.reparseRange(fileCopy, offset, offset, "xxx");
  59            }
  60            catch(IncorrectOperationException e){
  61              LOG.error(e);
  62            }
  63          }
  64        });
  65        PsiElement identifierCopy = fileCopy.findElementAt(offset);
  66        if (identifierCopy instanceof PsiIdentifier) {
  67          names = getNamesForIdentifier(project, (PsiIdentifier)identifierCopy);
  68        }
  69      }
  70      return names;
  71    }
  72
  73    @Nullable
  74    private static String[] getNamesForIdentifier(Project project, PsiIdentifier identifier){
  75      if (identifier.getParent() instanceof PsiVariable){
  76        PsiVariable var = (PsiVariable)identifier.getParent();
  77        if (identifier.equals(var.getNameIdentifier())){
  78          JavaCodeStyleManager codeStyleManager = JavaCodeStyleManager.getInstance(project);
  79          VariableKind variableKind = codeStyleManager.getVariableKind(var);
  80          PsiExpression initializer = var.getInitializer();
  81          if (var instanceof PsiParameter && ((PsiParameter)var).getDeclarationScope() instanceof PsiForeachStatement) {
  82            //synthesize initializer
  83            PsiForeachStatement foreachStatement = (PsiForeachStatement)((PsiParameter)var).getDeclarationScope();
  84            final PsiExpression iteratedValue = foreachStatement.getIteratedValue();
  85            if (iteratedValue != null) {
  86              try {
  87                final PsiArrayAccessExpression expr = (PsiArrayAccessExpression)JavaPsiFacade.getInstance(iteratedValue.getProject())
  88                  .getElementFactory().createExpressionFromText("a[0]", var);
  89                expr.getArrayExpression().replace(iteratedValue);
  90                initializer = expr; //note: non physical with no parent
  91              }
  92              catch (IncorrectOperationException e) {
  93                //do nothing
  94              }
  95            }
  96          }
  97          SuggestedNameInfo suggestedInfo = codeStyleManager.suggestVariableName(variableKind, null, initializer, var.getType());
  98          return suggestedInfo.names;
  99        }
 100      }
 101      return null;
 102    }
 103  }