Java 类com.intellij.psi.JavaRecursiveElementWalkingVisitor 实例源码

public static PsiExpression[] findVariableOccurrences(final PsiElement[] scopeElements, final PsiVariable variable) {
  final ArrayList<PsiExpression> result = new ArrayList<PsiExpression>();
  for (final PsiElement element : scopeElements) {
    element.accept(new JavaRecursiveElementWalkingVisitor() {
      @Override public void visitReferenceExpression(final PsiReferenceExpression expression) {
        super.visitReferenceExpression(expression);
        if (!expression.isQualified() && expression.isReferenceTo(variable)) {
          result.add(expression);
        }
      }
    });
  }
  return result.toArray(new PsiExpression[result.size()]);
}

private static List<PsiClass> getInnerClasses(PsiElement psiElement, final CharSequence fileBuffer)
{
    final Ref<ArrayList<PsiClass>> ourList = new Ref<ArrayList<PsiClass>>();
    ourList.set(null);

    if(psiElement != null && mayContainClassesInside(psiElement, fileBuffer))
    {
        psiElement.accept(new JavaRecursiveElementWalkingVisitor()
        {
            @Override
            public void visitClass(PsiClass aClass)
            {
                if(ourList.isNull())
                {
                    ourList.set(new ArrayList<PsiClass>());
                }
                ourList.get().add(aClass);
            }

            @Override
            public void visitTypeParameter(PsiTypeParameter classParameter)
            {
                // just skip (because type parameter is class - bad!)
            }
        });
    }

    return ourList.get();
}

@Override
protected Response handle(Request request) {
  Project project = findProject(request.file);
  if (project == null) {
    throw new RuntimeException("Cannot find the target project");
  }
  Application application = ApplicationManager.getApplication();
  Response response = new Response();
  application.runReadAction(
      () -> {
        PsiFile psiFile =
            PsiFileFactory.getInstance(project)
                .createFileFromText(JavaLanguage.INSTANCE, request.text);
        if (!(psiFile instanceof PsiJavaFile)) {
          throw new RuntimeException("Cannot parse as Java file");
        }
        PsiJavaFile psiJavaFile = (PsiJavaFile) psiFile;

        Set<String> processed = new HashSet<>();
        for (PsiClass psiClass : psiJavaFile.getClasses()) {
          psiClass.accept(
              new JavaRecursiveElementWalkingVisitor() {
                @Override
                public void visitReferenceElement(PsiJavaCodeReferenceElement reference) {
                  try {
                    if (reference.getQualifier() != null) {
                      return;
                    }
                    String name = reference.getReferenceName();
                    if (processed.contains(name)) {
                      return;
                    }
                    processed.add(name);

                    Set<String> candidates = new HashSet<>();
                    for (PsiClass t : new ImportClassFix(reference).getClassesToImport()) {
                      candidates.add(String.format("import %s;", t.getQualifiedName()));
                    }
                    if (!candidates.isEmpty()) {
                      response.choices.add(candidates.stream().sorted().collect(toList()));
                    }
                  } finally {
                    super.visitReferenceElement(reference);
                  }
                }
              });
        }
      });
  return response;
}