1 /*
2  * Copyright (C) 2014 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 dagger.internal.codegen;
17 
18 import dagger.MapKey;
19 import java.util.List;
20 import javax.lang.model.element.Element;
21 import javax.lang.model.element.ExecutableElement;
22 import javax.lang.model.element.TypeElement;
23 import javax.lang.model.type.TypeKind;
24 
25 import static dagger.internal.codegen.ErrorMessages.MAPKEY_WITHOUT_MEMBERS;
26 import static dagger.internal.codegen.ErrorMessages.UNWRAPPED_MAP_KEY_WITH_ARRAY_MEMBER;
27 import static dagger.internal.codegen.ErrorMessages.UNWRAPPED_MAP_KEY_WITH_TOO_MANY_MEMBERS;
28 import static javax.lang.model.util.ElementFilter.methodsIn;
29 
30 /**
31  * A validator for {@link MapKey} annotations.
32  *
33  * @author Chenying Hou
34  * @since 2.0
35  */
36 // TODO(dpb,gak): Should unwrapped MapKeys be required to have their single member be named "value"?
37 final class MapKeyValidator {
validate(Element element)38   ValidationReport<Element> validate(Element element) {
39     ValidationReport.Builder<Element> builder = ValidationReport.about(element);
40     List<ExecutableElement> members = methodsIn(((TypeElement) element).getEnclosedElements());
41     if (members.isEmpty()) {
42       builder.addError(MAPKEY_WITHOUT_MEMBERS, element);
43     } else if (element.getAnnotation(MapKey.class).unwrapValue()) {
44       if (members.size() > 1) {
45         builder.addError(UNWRAPPED_MAP_KEY_WITH_TOO_MANY_MEMBERS, element);
46       } else if (members.get(0).getReturnType().getKind() == TypeKind.ARRAY) {
47         builder.addError(UNWRAPPED_MAP_KEY_WITH_ARRAY_MEMBER, element);
48       }
49     }
50     return builder.build();
51   }
52 }
53