public static boolean hasAccessibleConstructor(PsiType type) {
    if (type instanceof PsiArrayType) return true;

    final PsiClass psiClass = PsiUtil.resolveClassInType(type);
    if (psiClass == null || psiClass.isEnum() || psiClass.isAnnotationType()) return false;

    if (!(psiClass instanceof PsiCompiledElement)) return true;

    final PsiMethod[] methods = psiClass.getConstructors();
    if (methods.length == 0) return true;

    for (final PsiMethod method : methods) {
      if (!method.hasModifierProperty(PsiModifier.PRIVATE)) return true;
    }
    return false;
  }
  public static boolean isSourceLevelAccessible(
      PsiElement context, PsiClass psiClass, final boolean pkgContext) {
    if (!JavaPsiFacade.getInstance(psiClass.getProject())
        .getResolveHelper()
        .isAccessible(psiClass, context, null)) {
      return false;
    }

    if (pkgContext) {
      PsiClass topLevel = PsiUtil.getTopLevelClass(psiClass);
      if (topLevel != null) {
        String fqName = topLevel.getQualifiedName();
        if (fqName != null && StringUtil.isEmpty(StringUtil.getPackageName(fqName))) {
          return false;
        }
      }
    }

    return true;
  }
 public static Set<String> getAllLookupStrings(@NotNull PsiMember member) {
   Set<String> allLookupStrings = ContainerUtil.newLinkedHashSet();
   String name = member.getName();
   allLookupStrings.add(name);
   PsiClass containingClass = member.getContainingClass();
   while (containingClass != null) {
     final String className = containingClass.getName();
     if (className == null) {
       break;
     }
     name = className + "." + name;
     allLookupStrings.add(name);
     final PsiElement parent = containingClass.getParent();
     if (!(parent instanceof PsiClass)) {
       break;
     }
     containingClass = (PsiClass) parent;
   }
   return allLookupStrings;
 }
 public static boolean containsMember(@Nullable PsiType qualifierType, @NotNull Object object) {
   if (qualifierType instanceof PsiArrayType
       && object instanceof PsiMember) { // length and clone()
     PsiFile file = ((PsiMember) object).getContainingFile();
     if (file == null || file.getVirtualFile() == null) { // yes, they're a bit dummy
       return true;
     }
   } else if (qualifierType instanceof PsiClassType) {
     PsiClass qualifierClass = ((PsiClassType) qualifierType).resolve();
     if (qualifierClass == null) return false;
     if (object instanceof PsiMethod
         && qualifierClass.findMethodBySignature((PsiMethod) object, false) != null) {
       return true;
     }
     if (object instanceof PsiMember) {
       return qualifierClass.equals(((PsiMember) object).getContainingClass());
     }
   }
   return false;
 }
  private static boolean canCallMethodsInConstructors(PsiClass aClass, boolean virtual) {
    for (PsiMethod constructor : aClass.getConstructors()) {
      if (!constructor.getLanguage().isKindOf(JavaLanguage.INSTANCE)) return true;

      PsiCodeBlock body = constructor.getBody();
      if (body == null) continue;

      for (PsiMethodCallExpression call :
          SyntaxTraverser.psiTraverser().withRoot(body).filter(PsiMethodCallExpression.class)) {
        PsiReferenceExpression methodExpression = call.getMethodExpression();
        if (methodExpression instanceof PsiThisExpression
            || methodExpression instanceof PsiSuperExpression) continue;
        if (!virtual) return true;

        PsiMethod target = call.resolveMethod();
        if (target != null && PsiUtil.canBeOverriden(target)) return true;
      }
    }

    return false;
  }
  public static int insertClassReference(
      PsiClass psiClass, PsiFile file, int startOffset, int endOffset) {
    final Project project = file.getProject();
    PsiDocumentManager documentManager = PsiDocumentManager.getInstance(project);
    documentManager.commitAllDocuments();

    final PsiManager manager = file.getManager();

    final Document document =
        FileDocumentManager.getInstance().getDocument(file.getViewProvider().getVirtualFile());

    final PsiReference reference = file.findReferenceAt(startOffset);
    if (reference != null) {
      final PsiElement resolved = reference.resolve();
      if (resolved instanceof PsiClass) {
        if (((PsiClass) resolved).getQualifiedName() == null
            || manager.areElementsEquivalent(psiClass, resolved)) {
          return endOffset;
        }
      }
    }

    String name = psiClass.getName();
    if (name == null) {
      return endOffset;
    }

    assert document != null;
    document.replaceString(startOffset, endOffset, name);

    int newEndOffset = startOffset + name.length();
    final RangeMarker toDelete = insertTemporary(newEndOffset, document, " ");

    documentManager.commitAllDocuments();

    PsiElement element = file.findElementAt(startOffset);
    if (element instanceof PsiIdentifier) {
      PsiElement parent = element.getParent();
      if (parent instanceof PsiJavaCodeReferenceElement
          && !((PsiJavaCodeReferenceElement) parent).isQualified()
          && !(parent.getParent() instanceof PsiPackageStatement)) {
        PsiJavaCodeReferenceElement ref = (PsiJavaCodeReferenceElement) parent;

        if (psiClass.isValid()
            && !psiClass.getManager().areElementsEquivalent(psiClass, resolveReference(ref))) {
          final boolean staticImport = ref instanceof PsiImportStaticReferenceElement;
          PsiElement newElement;
          try {
            newElement =
                staticImport
                    ? ((PsiImportStaticReferenceElement) ref).bindToTargetClass(psiClass)
                    : ref.bindToElement(psiClass);
          } catch (IncorrectOperationException e) {
            return endOffset; // can happen if fqn contains reserved words, for example
          }

          final RangeMarker rangeMarker = document.createRangeMarker(newElement.getTextRange());
          documentManager.doPostponedOperationsAndUnblockDocument(document);
          documentManager.commitDocument(document);

          newElement =
              CodeInsightUtilCore.findElementInRange(
                  file,
                  rangeMarker.getStartOffset(),
                  rangeMarker.getEndOffset(),
                  PsiJavaCodeReferenceElement.class,
                  JavaLanguage.INSTANCE);
          rangeMarker.dispose();
          if (newElement != null) {
            newEndOffset = newElement.getTextRange().getEndOffset();
            if (!(newElement instanceof PsiReferenceExpression)) {
              PsiReferenceParameterList parameterList =
                  ((PsiJavaCodeReferenceElement) newElement).getParameterList();
              if (parameterList != null) {
                newEndOffset = parameterList.getTextRange().getStartOffset();
              }
            }

            if (!staticImport
                && !psiClass
                    .getManager()
                    .areElementsEquivalent(psiClass, resolveReference((PsiReference) newElement))
                && !PsiUtil.isInnerClass(psiClass)) {
              final String qName = psiClass.getQualifiedName();
              if (qName != null) {
                document.replaceString(
                    newElement.getTextRange().getStartOffset(), newEndOffset, qName);
                newEndOffset = newElement.getTextRange().getStartOffset() + qName.length();
              }
            }
          }
        }
      }
    }

    if (toDelete.isValid()) {
      document.deleteString(toDelete.getStartOffset(), toDelete.getEndOffset());
    }

    return newEndOffset;
  }
  @NotNull
  private static LookupElement castQualifier(
      @NotNull LookupElement item,
      @Nullable final PsiTypeLookupItem castTypeItem,
      @Nullable PsiType plainQualifier,
      JavaCompletionProcessor processor) {
    if (castTypeItem == null) {
      return item;
    }
    if (plainQualifier != null) {
      Object o = item.getObject();
      if (o instanceof PsiMethod) {
        PsiType castType = castTypeItem.getType();
        if (plainQualifier instanceof PsiClassType && castType instanceof PsiClassType) {
          PsiMethod method = (PsiMethod) o;
          PsiClassType.ClassResolveResult plainResult =
              ((PsiClassType) plainQualifier).resolveGenerics();
          PsiClass plainClass = plainResult.getElement();
          if (plainClass != null && plainClass.findMethodBySignature(method, true) != null) {
            PsiClass castClass = ((PsiClassType) castType).resolveGenerics().getElement();

            if (castClass == null || !castClass.isInheritor(plainClass, true)) {
              return item;
            }

            PsiSubstitutor plainSub = plainResult.getSubstitutor();
            PsiSubstitutor castSub =
                TypeConversionUtil.getSuperClassSubstitutor(plainClass, (PsiClassType) castType);
            PsiType returnType = method.getReturnType();
            if (method.getSignature(plainSub).equals(method.getSignature(castSub))) {
              PsiType typeAfterCast = toRaw(castSub.substitute(returnType));
              PsiType typeDeclared = toRaw(plainSub.substitute(returnType));
              if (typeAfterCast != null
                  && typeDeclared != null
                  && typeAfterCast.isAssignableFrom(typeDeclared)
                  && processor.isAccessible(plainClass.findMethodBySignature(method, true))) {
                return item;
              }
            }
          }
        }
      } else if (containsMember(plainQualifier, o)) {
        return item;
      }
    }

    return LookupElementDecorator.withInsertHandler(
        item,
        new InsertHandlerDecorator<LookupElement>() {
          @Override
          public void handleInsert(
              InsertionContext context, LookupElementDecorator<LookupElement> item) {
            final Document document = context.getEditor().getDocument();
            context.commitDocument();
            final PsiFile file = context.getFile();
            final PsiJavaCodeReferenceElement ref =
                PsiTreeUtil.findElementOfClassAtOffset(
                    file, context.getStartOffset(), PsiJavaCodeReferenceElement.class, false);
            if (ref != null) {
              final PsiElement qualifier = ref.getQualifier();
              if (qualifier != null) {
                final CommonCodeStyleSettings settings = context.getCodeStyleSettings();

                final String parenSpace = settings.SPACE_WITHIN_PARENTHESES ? " " : "";
                document.insertString(qualifier.getTextRange().getEndOffset(), parenSpace + ")");

                final String spaceWithin = settings.SPACE_WITHIN_CAST_PARENTHESES ? " " : "";
                final String prefix = "(" + parenSpace + "(" + spaceWithin;
                final String spaceAfter = settings.SPACE_AFTER_TYPE_CAST ? " " : "";
                final int exprStart = qualifier.getTextRange().getStartOffset();
                document.insertString(exprStart, prefix + spaceWithin + ")" + spaceAfter);

                CompletionUtil.emulateInsertion(context, exprStart + prefix.length(), castTypeItem);
                PsiDocumentManager.getInstance(file.getProject())
                    .doPostponedOperationsAndUnblockDocument(document);
                context.getEditor().getCaretModel().moveToOffset(context.getTailOffset());
              }
            }

            item.getDelegate().handleInsert(context);
          }
        });
  }