1 /**
2  * Copyright (C) 2015 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 package com.google.inject.daggeradapter;
17 
18 import com.google.common.collect.ImmutableSet;
19 import com.google.inject.Binder;
20 import com.google.inject.Key;
21 import com.google.inject.internal.UniqueAnnotations;
22 import com.google.inject.multibindings.Multibinder;
23 import com.google.inject.spi.InjectionPoint;
24 import com.google.inject.spi.ModuleAnnotatedMethodScanner;
25 
26 import dagger.Provides;
27 import dagger.Provides.Type;
28 
29 import java.lang.annotation.Annotation;
30 import java.lang.reflect.Method;
31 import java.util.Set;
32 
33 /**
34  * A scanner to process provider methods on Dagger modules.
35  *
36  * @author cgruber@google.com (Christian Gruber)
37  */
38 final class DaggerMethodScanner extends ModuleAnnotatedMethodScanner {
39   static DaggerMethodScanner INSTANCE = new DaggerMethodScanner();
40 
annotationClasses()41   @Override public Set<? extends Class<? extends Annotation>> annotationClasses() {
42     return ImmutableSet.of(dagger.Provides.class);
43   }
44 
prepareMethod( Binder binder, Annotation rawAnnotation, Key<T> key, InjectionPoint injectionPoint)45   @Override public <T> Key<T> prepareMethod(
46       Binder binder, Annotation rawAnnotation, Key<T> key, InjectionPoint injectionPoint) {
47     Method providesMethod = (Method) injectionPoint.getMember();
48     Provides annotation = (Provides) rawAnnotation;
49     switch (annotation.type()) {
50       case UNIQUE:
51         return key;
52       case MAP:
53         /* TODO(cgruber) implement map bindings */
54         binder.addError("Map bindings are not yet supported.");
55       case SET:
56         return processSetBinding(binder, key);
57       case SET_VALUES:
58         binder.addError(Type.SET_VALUES.name() + " contributions are not supported by Guice.",
59             providesMethod);
60         return key;
61       default:
62         binder.addError("Unknown @Provides type " + annotation.type() + ".", providesMethod);
63         return key;
64     }
65   }
66 
processSetBinding(Binder binder, Key<T> key)67   private static <T> Key<T> processSetBinding(Binder binder, Key<T> key) {
68     Multibinder<T> setBinder = Multibinder.newSetBinder(binder, key.getTypeLiteral());
69     Key<T> newKey = Key.get(key.getTypeLiteral(), UniqueAnnotations.create());
70     setBinder.addBinding().to(newKey);
71     return newKey;
72   }
73 
DaggerMethodScanner()74   private DaggerMethodScanner() {}
75 }