SupertypesHierarchyTreeStructure.java

/*
 * Copyright 2000-2013 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.intellij.ide.hierarchy.type;

import com.intellij.codeInsight.AnnotationTargetUtil;
import com.intellij.ide.hierarchy.HierarchyNodeDescriptor;
import com.intellij.ide.hierarchy.HierarchyTreeStructure;
import com.intellij.openapi.project.Project;
import com.intellij.psi.*;
import com.intellij.psi.util.PsiUtil;
import com.intellij.util.ArrayUtil;
import com.intellij.util.containers.ContainerUtil;
import org.jetbrains.annotations.NotNull;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;

public final class SupertypesHierarchyTreeStructure extends HierarchyTreeStructure {

  public SupertypesHierarchyTreeStructure(final Project project, final PsiClass aClass) {
    super(project, new TypeHierarchyNodeDescriptor(project, null, aClass, true));
  }

  @NotNull
  protected final Object[] buildChildren(@NotNull final HierarchyNodeDescriptor descriptor) {
    final Object element = ((TypeHierarchyNodeDescriptor)descriptor).getPsiClass();
    if (element instanceof PsiClass) {
      final PsiClass psiClass = (PsiClass)element;
      final PsiClass[] supers = getSupers(psiClass);
      final List<HierarchyNodeDescriptor> descriptors = new ArrayList<>();
      final PsiClass objectClass = JavaPsiFacade.getInstance(myProject).findClass(CommonClassNames.JAVA_LANG_OBJECT, psiClass.getResolveScope());
      for (PsiClass aSuper : supers) {
        if (!psiClass.isInterface() || !aSuper.equals(objectClass)) {
          descriptors.add(new TypeHierarchyNodeDescriptor(myProject, descriptor, aSuper, false));
        }
      }
      return descriptors.toArray(new HierarchyNodeDescriptor[descriptors.size()]);
    } else if (element instanceof PsiFunctionalExpression) {
      final PsiClass functionalInterfaceClass = PsiUtil.resolveClassInType(((PsiFunctionalExpression)element).getFunctionalInterfaceType());
      if (functionalInterfaceClass != null) {
        return new HierarchyNodeDescriptor[] {new TypeHierarchyNodeDescriptor(myProject, descriptor, functionalInterfaceClass, false)};
      }
    }
    return ArrayUtil.EMPTY_OBJECT_ARRAY;
  }

  @NotNull
  private static PsiClass[] getSupers(@NotNull PsiClass psiClass) {
    if (psiClass.isAnnotationType()) {
      return getMetaAnnotations(psiClass);
    }
    return psiClass.getSupers();
  }

  @NotNull
  private static PsiClass[] getMetaAnnotations(@NotNull PsiClass psiClass) {
    Set<PsiClass> supers = ContainerUtil.newHashSet();
    final PsiModifierList modifierList = psiClass.getModifierList();
    if (modifierList != null) {
      for (PsiAnnotation annotation : modifierList.getAnnotations()) {
        if (isJavaLangAnnotation(annotation)) continue;
        PsiJavaCodeReferenceElement ref = annotation.getNameReferenceElement();
        if (ref != null) {
          PsiElement annotationType = ref.resolve();
          if (annotationType instanceof PsiClass) {
            final PsiClass aClass = (PsiClass)annotationType;
            final PsiAnnotation.TargetType target = AnnotationTargetUtil
              .findAnnotationTarget(aClass, PsiAnnotation.TargetType.TYPE, PsiAnnotation.TargetType.ANNOTATION_TYPE);
            if (target !=  null && target != PsiAnnotation.TargetType.UNKNOWN) {
                supers.add(aClass);
            }
          }
        }
      }
    }
    return supers.toArray(new PsiClass[supers.size()]);
  }

  private static boolean isJavaLangAnnotation(@NotNull  PsiAnnotation annotation) {
    final String qualifiedName = annotation.getQualifiedName();
    return qualifiedName != null && qualifiedName.startsWith("java.lang.annotation");
  }
}