java/java-impl/src/com/intellij/codeInsight/completion/CollectionsUtilityMethodsProvider.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 org.jetbrains.annotations.NotNull;
  19 import org.jetbrains.annotations.NonNls;
  20 import com.intellij.util.ProcessingContext;
  21 import com.intellij.psi.*;
  22 import static com.intellij.psi.CommonClassNames.*;
  23 import com.intellij.codeInsight.lookup.AutoCompletionPolicy;
  24
  25 /**
  26 * @author peter
  27 */
  28 class CollectionsUtilityMethodsProvider extends CompletionProvider<JavaSmartCompletionParameters> {
  29   public void addCompletions(@NotNull final JavaSmartCompletionParameters parameters, final ProcessingContext context, @NotNull final CompletionResultSet result) {
  30     final PsiElement element = parameters.getPosition();
  31
  32     final PsiElement parent = element.getParent();
  33     if (parent instanceof PsiReferenceExpression && ((PsiReferenceExpression)parent).getQualifierExpression() != null) return;
  34
  35     final PsiClass collectionsClass =
  36         JavaPsiFacade.getInstance(element.getProject()).findClass(JAVA_UTIL_COLLECTIONS, element.getResolveScope());
  37     if (collectionsClass == null) return;
  38
  39     final PsiType type = parameters.getExpectedType();
  40     final PsiType defaultType = parameters.getDefaultType();
  41     final PsiElement pparent = parent.getParent();
  42     if (parameters.getInvocationCount() > 1 ||
  43         pparent instanceof PsiReturnStatement ||
  44         pparent instanceof PsiConditionalExpression && pparent.getParent() instanceof PsiReturnStatement) {
  45       addCollectionMethod(result, type, defaultType, JAVA_UTIL_LIST, "emptyList", collectionsClass);
  46       addCollectionMethod(result, type, defaultType, JAVA_UTIL_SET, "emptySet", collectionsClass);
  47       addCollectionMethod(result, type, defaultType, JAVA_UTIL_MAP, "emptyMap", collectionsClass);
  48     }
  49
  50     if (parameters.getInvocationCount() > 1) {
  51       addCollectionMethod(result, type, defaultType, JAVA_UTIL_LIST, "singletonList", collectionsClass);
  52       addCollectionMethod(result, type, defaultType, JAVA_UTIL_SET, "singleton", collectionsClass);
  53       addCollectionMethod(result, type, defaultType, JAVA_UTIL_MAP, "singletonMap", collectionsClass);
  54
  55       addCollectionMethod(result, type, defaultType, JAVA_UTIL_COLLECTION, "unmodifiableCollection", collectionsClass);
  56       addCollectionMethod(result, type, defaultType, JAVA_UTIL_LIST, "unmodifiableList", collectionsClass);
  57       addCollectionMethod(result, type, defaultType, JAVA_UTIL_SET, "unmodifiableSet", collectionsClass);
  58       addCollectionMethod(result, type, defaultType, JAVA_UTIL_MAP, "unmodifiableMap", collectionsClass);
  59       addCollectionMethod(result, type, defaultType, "java.util.SortedSet", "unmodifiableSortedSet", collectionsClass);
  60       addCollectionMethod(result, type, defaultType, "java.util.SortedMap", "unmodifiableSortedMap", collectionsClass);
  61     }
  62
  63   }
  64
  65   private static void addCollectionMethod(final CompletionResultSet result, final PsiType expectedType,
  66                                    final PsiType defaultType, final String baseClassName,
  67                                    @NonNls final String method, @NotNull final PsiClass collectionsClass) {
  68     if (isClassType(expectedType, baseClassName) || isClassType(expectedType, JAVA_UTIL_COLLECTION) ||
  69         isClassType(defaultType, baseClassName) || isClassType(defaultType, JAVA_UTIL_COLLECTION)) {
  70       final PsiMethod[] methods = collectionsClass.findMethodsByName(method, false);
  71       if (methods.length != 0) {
  72         result.addElement(JavaCompletionUtil.qualify(new JavaMethodCallElement(methods[0]).setAutoCompletionPolicy(AutoCompletionPolicy.NEVER_AUTOCOMPLETE)));
  73       }
  74     }
  75   }
  76
  77   private static boolean isClassType(final PsiType type, final String className) {
  78     if (type instanceof PsiClassType) {
  79       final PsiClass psiClass = ((PsiClassType)type).resolve();
  80       return psiClass != null && className.equals(psiClass.getQualifiedName());
  81     }
  82     return false;
  83   }
  84
  85 }