java/java-impl/src/com/intellij/codeInsight/completion/NullSmartCompletionContributor.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.completion;
  17
  18 import com.intellij.codeInsight.ExpectedTypeInfo;
  19 import com.intellij.codeInsight.lookup.LookupElement;
  20 import com.intellij.codeInsight.lookup.LookupItem;
  21 import com.intellij.openapi.util.Ref;
  22 import static com.intellij.patterns.PsiJavaPatterns.psiElement;
  23 import static com.intellij.patterns.StandardPatterns.and;
  24 import static com.intellij.patterns.StandardPatterns.not;
  25 import com.intellij.psi.PsiKeyword;
  26 import com.intellij.psi.PsiPrimitiveType;
  27 import com.intellij.psi.PsiType;
  28 import com.intellij.util.Consumer;
  29 import org.jetbrains.annotations.NonNls;
  30
  31 import java.util.Collection;
  32
  33 /**
  34  * @author peter
  35  */
  36 public class NullSmartCompletionContributor extends CompletionContributor{
  37   public NullSmartCompletionContributor() {
  38     extend(CompletionType.SMART, and(JavaSmartCompletionContributor.INSIDE_EXPRESSION,
  39                                                       not(psiElement().afterLeaf("."))), new ExpectedTypeBasedCompletionProvider() {
  40       protected void addCompletions(final CompletionParameters parameters,
  41                                     final CompletionResultSet result, final Collection<ExpectedTypeInfo> infos) {
  42         final Ref<Boolean> empty = Ref.create(true);
  43         result.runRemainingContributors(parameters, new Consumer<LookupElement>() {
  44           public void consume(final LookupElement lookupElement) {
  45             empty.set(false);
  46             result.addElement(lookupElement);
  47           }
  48         });
  49
  50         @NonNls final String prefix = result.getPrefixMatcher().getPrefix();
  51         if (empty.get().booleanValue() && prefix.startsWith("n")) {
  52           for (final ExpectedTypeInfo info : infos) {
  53             if (!(info.getType() instanceof PsiPrimitiveType)) {
  54               final LookupItem item = (LookupItem)BasicExpressionCompletionContributor.createKeywordLookupItem(parameters.getPosition(), PsiKeyword.NULL);
  55               item.setAttribute(LookupItem.TYPE, PsiType.NULL);
  56               result.addElement(JavaSmartCompletionContributor.decorate(item, infos));
  57               return;
  58             }
  59           }
  60         }
  61       }
  62     });
  63   }
  64
  65 }