/*
 * Copyright (C) 2011 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.Binder;
import com.google.inject.Binding;
import com.google.inject.Injector;
import com.google.inject.internal.util.StackTraceElements;
import java.lang.reflect.Member;

A combination of a Dependency and the source where the dependency was bound. 
Author:
sameb@google.com (Sam Berlin)
Since:
4.0
Deprecated:
The only use of this object is for ProvisionInvocation.getDependencyChain() which is also deprecated. This object will also be removed in Guice 4.4./**
 * A combination of a {@link Dependency} and the {@link Binding#getSource() source} where the
 * dependency was bound.
 *
 * @author sameb@google.com (Sam Berlin)
 * @since 4.0
 * @deprecated The only use of this object is for {@link
 *     ProvisionListener.ProvisionInvocation#getDependencyChain()} which is also deprecated. This
 *     object will also be removed in Guice 4.4.
 */
@Deprecated
public final class DependencyAndSource {
  private final Dependency<?> dependency;
  private final Object source;

  public DependencyAndSource(Dependency<?> dependency, Object source) {
    this.dependency = dependency;
    this.source = source;
  }

  
Returns the Dependency, if one exists. For anything that can be referenced by Injector.getBinding, a dependency exists. A dependency will not exist (and this will return null) for types initialized with Binder.requestInjection or Injector.injectMembers(Object), nor will it exist for objects injected into Providers bound with LinkedBindingBuilder#toProvider(Provider). /**
   * Returns the Dependency, if one exists. For anything that can be referenced by {@link
   * Injector#getBinding}, a dependency exists. A dependency will not exist (and this will return
   * null) for types initialized with {@link Binder#requestInjection} or {@link
   * Injector#injectMembers(Object)}, nor will it exist for objects injected into Providers bound
   * with LinkedBindingBuilder#toProvider(Provider).
   */
  public Dependency<?> getDependency() {
    return dependency;
  }

  
Returns a string describing where this dependency was bound. If the binding was just-in-time,
there is no valid binding source, so this describes the class in question.
/**
   * Returns a string describing where this dependency was bound. If the binding was just-in-time,
   * there is no valid binding source, so this describes the class in question.
   */
  public String getBindingSource() {
    if (source instanceof Class) {
      return StackTraceElements.forType((Class) source).toString();
    } else if (source instanceof Member) {
      return StackTraceElements.forMember((Member) source).toString();
    } else {
      return source.toString();
    }
  }

  @Override
  public String toString() {
    Dependency<?> dep = getDependency();
    Object source = getBindingSource();
    if (dep != null) {
      return "Dependency: " + dep + ", source: " + source;
    } else {
      return "Source: " + source;
    }
  }
}