limpbizkit | 76c24b1 | 2008-12-25 04:32:41 +0000 | [diff] [blame] | 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 | |
| 17 | package com.google.inject.internal; |
| 18 | |
| 19 | import com.google.inject.Scope; |
| 20 | import com.google.inject.Scopes; |
| 21 | import com.google.inject.Singleton; |
| 22 | import com.google.inject.Stage; |
limpbizkit | 03b81a6 | 2009-03-18 05:34:39 +0000 | [diff] [blame] | 23 | import com.google.inject.binder.ScopedBindingBuilder; |
limpbizkit | 76c24b1 | 2008-12-25 04:32:41 +0000 | [diff] [blame] | 24 | import com.google.inject.spi.BindingScopingVisitor; |
| 25 | import java.lang.annotation.Annotation; |
| 26 | |
| 27 | /** |
| 28 | * References a scope, either directly (as a scope instance), or indirectly (as a scope annotation). |
| 29 | * The scope's eager or laziness is also exposed. |
| 30 | * |
| 31 | * @author jessewilson@google.com (Jesse Wilson) |
| 32 | */ |
| 33 | public abstract class Scoping { |
| 34 | |
| 35 | /** |
| 36 | * No scoping annotation has been applied. Note that this is different from {@code |
| 37 | * in(Scopes.NO_SCOPE)}, where the 'NO_SCOPE' has been explicitly applied. |
| 38 | */ |
| 39 | public static final Scoping UNSCOPED = new Scoping() { |
| 40 | public <V> V acceptVisitor(BindingScopingVisitor<V> visitor) { |
| 41 | return visitor.visitNoScoping(); |
| 42 | } |
| 43 | |
| 44 | @Override public Scope getScopeInstance() { |
| 45 | return Scopes.NO_SCOPE; |
| 46 | } |
| 47 | |
| 48 | @Override public String toString() { |
| 49 | return Scopes.NO_SCOPE.toString(); |
| 50 | } |
limpbizkit | 03b81a6 | 2009-03-18 05:34:39 +0000 | [diff] [blame] | 51 | |
| 52 | public void applyTo(ScopedBindingBuilder scopedBindingBuilder) { |
| 53 | // do nothing |
| 54 | } |
limpbizkit | 76c24b1 | 2008-12-25 04:32:41 +0000 | [diff] [blame] | 55 | }; |
| 56 | |
| 57 | public static final Scoping SINGLETON_ANNOTATION = new Scoping() { |
| 58 | public <V> V acceptVisitor(BindingScopingVisitor<V> visitor) { |
| 59 | return visitor.visitScopeAnnotation(Singleton.class); |
| 60 | } |
| 61 | |
| 62 | @Override public Class<? extends Annotation> getScopeAnnotation() { |
| 63 | return Singleton.class; |
| 64 | } |
| 65 | |
| 66 | @Override public String toString() { |
| 67 | return Singleton.class.getName(); |
| 68 | } |
limpbizkit | 03b81a6 | 2009-03-18 05:34:39 +0000 | [diff] [blame] | 69 | |
| 70 | public void applyTo(ScopedBindingBuilder scopedBindingBuilder) { |
| 71 | scopedBindingBuilder.in(Singleton.class); |
| 72 | } |
limpbizkit | 76c24b1 | 2008-12-25 04:32:41 +0000 | [diff] [blame] | 73 | }; |
| 74 | |
| 75 | public static final Scoping SINGLETON_INSTANCE = new Scoping() { |
| 76 | public <V> V acceptVisitor(BindingScopingVisitor<V> visitor) { |
| 77 | return visitor.visitScope(Scopes.SINGLETON); |
| 78 | } |
| 79 | |
| 80 | @Override public Scope getScopeInstance() { |
| 81 | return Scopes.SINGLETON; |
| 82 | } |
| 83 | |
| 84 | @Override public String toString() { |
| 85 | return Scopes.SINGLETON.toString(); |
| 86 | } |
limpbizkit | 03b81a6 | 2009-03-18 05:34:39 +0000 | [diff] [blame] | 87 | |
| 88 | public void applyTo(ScopedBindingBuilder scopedBindingBuilder) { |
| 89 | scopedBindingBuilder.in(Scopes.SINGLETON); |
| 90 | } |
limpbizkit | 76c24b1 | 2008-12-25 04:32:41 +0000 | [diff] [blame] | 91 | }; |
| 92 | |
| 93 | public static final Scoping EAGER_SINGLETON = new Scoping() { |
| 94 | public <V> V acceptVisitor(BindingScopingVisitor<V> visitor) { |
| 95 | return visitor.visitEagerSingleton(); |
| 96 | } |
| 97 | |
| 98 | @Override public Scope getScopeInstance() { |
| 99 | return Scopes.SINGLETON; |
| 100 | } |
| 101 | |
| 102 | @Override public String toString() { |
| 103 | return "eager singleton"; |
| 104 | } |
limpbizkit | 03b81a6 | 2009-03-18 05:34:39 +0000 | [diff] [blame] | 105 | |
| 106 | public void applyTo(ScopedBindingBuilder scopedBindingBuilder) { |
| 107 | scopedBindingBuilder.asEagerSingleton(); |
| 108 | } |
limpbizkit | 76c24b1 | 2008-12-25 04:32:41 +0000 | [diff] [blame] | 109 | }; |
| 110 | |
| 111 | public static Scoping forAnnotation(final Class<? extends Annotation> scopingAnnotation) { |
| 112 | if (scopingAnnotation == Singleton.class) { |
| 113 | return SINGLETON_ANNOTATION; |
| 114 | } |
| 115 | |
| 116 | return new Scoping() { |
| 117 | public <V> V acceptVisitor(BindingScopingVisitor<V> visitor) { |
| 118 | return visitor.visitScopeAnnotation(scopingAnnotation); |
| 119 | } |
| 120 | |
| 121 | @Override public Class<? extends Annotation> getScopeAnnotation() { |
| 122 | return scopingAnnotation; |
| 123 | } |
| 124 | |
| 125 | @Override public String toString() { |
| 126 | return scopingAnnotation.getName(); |
| 127 | } |
limpbizkit | 03b81a6 | 2009-03-18 05:34:39 +0000 | [diff] [blame] | 128 | |
| 129 | public void applyTo(ScopedBindingBuilder scopedBindingBuilder) { |
| 130 | scopedBindingBuilder.in(scopingAnnotation); |
| 131 | } |
limpbizkit | 76c24b1 | 2008-12-25 04:32:41 +0000 | [diff] [blame] | 132 | }; |
| 133 | } |
| 134 | |
| 135 | public static Scoping forInstance(final Scope scope) { |
| 136 | if (scope == Scopes.SINGLETON) { |
| 137 | return SINGLETON_INSTANCE; |
| 138 | } |
| 139 | |
| 140 | return new Scoping() { |
| 141 | public <V> V acceptVisitor(BindingScopingVisitor<V> visitor) { |
| 142 | return visitor.visitScope(scope); |
| 143 | } |
| 144 | |
| 145 | @Override public Scope getScopeInstance() { |
| 146 | return scope; |
| 147 | } |
| 148 | |
| 149 | @Override public String toString() { |
| 150 | return scope.toString(); |
| 151 | } |
limpbizkit | 03b81a6 | 2009-03-18 05:34:39 +0000 | [diff] [blame] | 152 | |
| 153 | public void applyTo(ScopedBindingBuilder scopedBindingBuilder) { |
| 154 | scopedBindingBuilder.in(scope); |
| 155 | } |
limpbizkit | 76c24b1 | 2008-12-25 04:32:41 +0000 | [diff] [blame] | 156 | }; |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * Returns true if this scope was explicitly applied. If no scope was explicitly applied then the |
| 161 | * scoping annotation will be used. |
| 162 | */ |
| 163 | public boolean isExplicitlyScoped() { |
| 164 | return this != UNSCOPED; |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * Returns true if this is the default scope. In this case a new instance will be provided for |
| 169 | * each injection. |
| 170 | */ |
| 171 | public boolean isNoScope() { |
| 172 | return getScopeInstance() == Scopes.NO_SCOPE; |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * Returns true if this scope is a singleton that should be loaded eagerly in {@code stage}. |
| 177 | */ |
| 178 | public boolean isEagerSingleton(Stage stage) { |
| 179 | if (this == EAGER_SINGLETON) { |
| 180 | return true; |
| 181 | } |
| 182 | |
| 183 | if (stage == Stage.PRODUCTION) { |
| 184 | return this == SINGLETON_ANNOTATION || this == SINGLETON_INSTANCE; |
| 185 | } |
| 186 | |
| 187 | return false; |
| 188 | } |
| 189 | |
| 190 | /** |
| 191 | * Returns the scope instance, or {@code null} if that isn't known for this instance. |
| 192 | */ |
| 193 | public Scope getScopeInstance() { |
| 194 | return null; |
| 195 | } |
| 196 | |
| 197 | /** |
| 198 | * Returns the scope annotation, or {@code null} if that isn't known for this instance. |
| 199 | */ |
| 200 | public Class<? extends Annotation> getScopeAnnotation() { |
| 201 | return null; |
| 202 | } |
| 203 | |
| 204 | public abstract <V> V acceptVisitor(BindingScopingVisitor<V> visitor); |
| 205 | |
limpbizkit | 03b81a6 | 2009-03-18 05:34:39 +0000 | [diff] [blame] | 206 | public abstract void applyTo(ScopedBindingBuilder scopedBindingBuilder); |
| 207 | |
limpbizkit | 76c24b1 | 2008-12-25 04:32:41 +0000 | [diff] [blame] | 208 | private Scoping() {} |
| 209 | } |