/*
 * Copyright (C) 2008 Google Inc.
 *
 * 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.google.inject.spi;

import com.google.inject.Scope;
import java.lang.annotation.Annotation;

/**
 * No-op visitor for subclassing. All interface methods simply delegate to {@link #visitOther()},
 * returning its result.
 *
 * @param <V> any type to be returned by the visit method. Use {@link Void} with {@code return null}
 *     if no return type is needed.
 * @author jessewilson@google.com (Jesse Wilson)
 * @since 2.0
 */
public class DefaultBindingScopingVisitor<V> implements BindingScopingVisitor<V> {

  /** Default visit implementation. Returns {@code null}. */
  protected V visitOther() {
    return null;
  }

  @Override
  public V visitEagerSingleton() {
    return visitOther();
  }

  @Override
  public V visitScope(Scope scope) {
    return visitOther();
  }

  @Override
  public V visitScopeAnnotation(Class<? extends Annotation> scopeAnnotation) {
    return visitOther();
  }

  @Override
  public V visitNoScoping() {
    return visitOther();
  }
}