java/java-impl/src/com/intellij/ide/hierarchy/type/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.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 org.jetbrains.annotations.NotNull;

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

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 = psiClass.getSupers();
      final List<HierarchyNodeDescriptor> descriptors = new ArrayList<HierarchyNodeDescriptor>();
      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;
  }
}