1/**
2 * Copyright (C) 2008 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.inject.spi;
18
19import com.google.inject.Injector;
20import com.google.inject.Key;
21
22import java.util.List;
23import java.util.Set;
24
25/**
26 * A private collection of elements that are hidden from the enclosing injector or module by
27 * default. See {@link com.google.inject.PrivateModule PrivateModule} for details.
28 *
29 * @author jessewilson@google.com (Jesse Wilson)
30 * @since 2.0
31 */
32public interface PrivateElements extends Element {
33
34  /**
35   * Returns the configuration information in this private environment.
36   */
37  List<Element> getElements();
38
39  /**
40   * Returns the child injector that hosts these private elements, or null if the elements haven't
41   * been used to create an injector.
42   */
43  Injector getInjector();
44
45  /**
46   * Returns the unique exposed keys for these private elements.
47   */
48  Set<Key<?>> getExposedKeys();
49
50  /**
51   * Returns an arbitrary object containing information about the "place" where this key was
52   * exposed. Used by Guice in the production of descriptive error messages.
53   *
54   * <p>Tools might specially handle types they know about; {@code StackTraceElement} is a good
55   * example. Tools should simply call {@code toString()} on the source object if the type is
56   * unfamiliar.
57   *
58   * @param key one of the keys exposed by this module.
59   */
60  Object getExposedSource(Key<?> key);
61}
62