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 */
16package dagger.internal.codegen;
17
18import com.google.auto.common.MoreElements;
19import com.google.auto.common.MoreTypes;
20import com.google.common.base.Optional;
21import java.util.Iterator;
22import java.util.List;
23import javax.lang.model.element.AnnotationMirror;
24import javax.lang.model.element.ExecutableElement;
25import javax.lang.model.element.TypeElement;
26import javax.lang.model.element.VariableElement;
27import javax.lang.model.type.DeclaredType;
28import javax.lang.model.type.ExecutableType;
29import javax.lang.model.type.TypeKind;
30import javax.lang.model.type.TypeMirror;
31import javax.lang.model.util.Types;
32
33import static com.google.common.base.Preconditions.checkState;
34import static dagger.internal.codegen.ErrorMessages.stripCommonTypePrefixes;
35
36/**
37 * Formats the signature of an {@link ExecutableElement} suitable for use in error messages.
38 *
39 * @author Christian Gruber
40 * @since 2.0
41 */
42final class MethodSignatureFormatter extends Formatter<ExecutableElement> {
43  private final Types types;
44
45  MethodSignatureFormatter(Types types) {
46    this.types = types;
47  }
48
49  @Override public String format(ExecutableElement method) {
50    return format(method, Optional.<DeclaredType>absent());
51  }
52
53  /**
54   * Formats an ExecutableElement as if it were contained within the container, if the container is
55   * present.
56   */
57  public String format(ExecutableElement method, Optional<DeclaredType> container) {
58    StringBuilder builder = new StringBuilder();
59    TypeElement type = MoreElements.asType(method.getEnclosingElement());
60    ExecutableType executableType = MoreTypes.asExecutable(method.asType());
61    if (container.isPresent()) {
62      executableType = MoreTypes.asExecutable(types.asMemberOf(container.get(), method));
63      type = MoreElements.asType(container.get().asElement());
64    }
65
66    // TODO(cgruber): AnnotationMirror formatter.
67    List<? extends AnnotationMirror> annotations = method.getAnnotationMirrors();
68    if (!annotations.isEmpty()) {
69      Iterator<? extends AnnotationMirror> annotationIterator = annotations.iterator();
70      for (int i = 0; annotationIterator.hasNext(); i++) {
71        if (i > 0) {
72          builder.append(' ');
73        }
74        builder.append(ErrorMessages.format(annotationIterator.next()));
75      }
76      builder.append(' ');
77    }
78    builder.append(nameOfType(executableType.getReturnType()));
79    builder.append(' ');
80    builder.append(type.getQualifiedName());
81    builder.append('.');
82    builder.append(method.getSimpleName());
83    builder.append('(');
84    checkState(method.getParameters().size() == executableType.getParameterTypes().size());
85    Iterator<? extends VariableElement> parameters = method.getParameters().iterator();
86    Iterator<? extends TypeMirror> parameterTypes = executableType.getParameterTypes().iterator();
87    for (int i = 0; parameters.hasNext(); i++) {
88      if (i > 0) {
89        builder.append(", ");
90      }
91      appendParameter(builder, parameters.next(), parameterTypes.next());
92    }
93    builder.append(')');
94    return builder.toString();
95  }
96
97  private static void appendParameter(StringBuilder builder, VariableElement parameter,
98      TypeMirror type) {
99    Optional<AnnotationMirror> qualifier = InjectionAnnotations.getQualifier(parameter);
100    if (qualifier.isPresent()) {
101      builder.append(ErrorMessages.format(qualifier.get())).append(' ');
102    }
103    builder.append(nameOfType(type));
104  }
105
106  private static String nameOfType(TypeMirror type) {
107    if (type.getKind().isPrimitive()) {
108      return MoreTypes.asPrimitiveType(type).toString();
109    } else if (type.getKind() == TypeKind.VOID) {
110      return "void";
111    } else {
112      return stripCommonTypePrefixes(MoreTypes.asDeclared(type).toString());
113    }
114  }
115}
116