dagger.internal.codegen.InjectConstructorValidator.java Source code

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Here is the source code for dagger.internal.codegen.InjectConstructorValidator.java

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/*
 * Copyright (C) 2014 Google, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package dagger.internal.codegen;

import com.google.auto.common.MoreElements;
import com.google.common.base.Predicate;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.ImmutableSet;
import java.util.Set;
import javax.inject.Inject;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.Modifier;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.util.ElementFilter;

import static com.google.auto.common.MoreElements.isAnnotationPresent;
import static dagger.internal.codegen.ErrorMessages.INJECT_CONSTRUCTOR_ON_ABSTRACT_CLASS;
import static dagger.internal.codegen.ErrorMessages.INJECT_CONSTRUCTOR_ON_INNER_CLASS;
import static dagger.internal.codegen.ErrorMessages.INJECT_INTO_PRIVATE_CLASS;
import static dagger.internal.codegen.ErrorMessages.INJECT_ON_PRIVATE_CONSTRUCTOR;
import static dagger.internal.codegen.ErrorMessages.MULTIPLE_INJECT_CONSTRUCTORS;
import static dagger.internal.codegen.ErrorMessages.MULTIPLE_QUALIFIERS;
import static dagger.internal.codegen.ErrorMessages.MULTIPLE_SCOPES;
import static dagger.internal.codegen.ErrorMessages.QUALIFIER_ON_INJECT_CONSTRUCTOR;
import static dagger.internal.codegen.InjectionAnnotations.getQualifiers;
import static dagger.internal.codegen.InjectionAnnotations.getScopes;
import static javax.lang.model.element.Modifier.ABSTRACT;
import static javax.lang.model.element.Modifier.PRIVATE;
import static javax.lang.model.element.Modifier.STATIC;

/**
 * A {@linkplain ValidationReport validator} for {@link Inject} constructors.
 *
 * @author Gregory Kick
 * @since 2.0
 */
final class InjectConstructorValidator {
    ValidationReport<TypeElement> validate(ExecutableElement constructorElement) {
        ValidationReport.Builder<TypeElement> builder = ValidationReport
                .about(MoreElements.asType(constructorElement.getEnclosingElement()));
        if (constructorElement.getModifiers().contains(PRIVATE)) {
            builder.addError(INJECT_ON_PRIVATE_CONSTRUCTOR, constructorElement);
        }

        for (AnnotationMirror qualifier : getQualifiers(constructorElement)) {
            builder.addError(QUALIFIER_ON_INJECT_CONSTRUCTOR, constructorElement, qualifier);
        }

        for (VariableElement parameter : constructorElement.getParameters()) {
            ImmutableSet<? extends AnnotationMirror> qualifiers = getQualifiers(parameter);
            if (qualifiers.size() > 1) {
                for (AnnotationMirror qualifier : qualifiers) {
                    builder.addError(MULTIPLE_QUALIFIERS, constructorElement, qualifier);
                }
            }
        }

        TypeElement enclosingElement = MoreElements.asType(constructorElement.getEnclosingElement());
        Set<Modifier> typeModifiers = enclosingElement.getModifiers();

        if (typeModifiers.contains(PRIVATE)) {
            builder.addError(INJECT_INTO_PRIVATE_CLASS, constructorElement);
        }

        if (typeModifiers.contains(ABSTRACT)) {
            builder.addError(INJECT_CONSTRUCTOR_ON_ABSTRACT_CLASS, constructorElement);
        }

        if (enclosingElement.getNestingKind().isNested() && !typeModifiers.contains(STATIC)) {
            builder.addError(INJECT_CONSTRUCTOR_ON_INNER_CLASS, constructorElement);
        }

        // This is computationally expensive, but probably preferable to a giant index
        FluentIterable<ExecutableElement> injectConstructors = FluentIterable
                .from(ElementFilter.constructorsIn(enclosingElement.getEnclosedElements()))
                .filter(new Predicate<ExecutableElement>() {
                    @Override
                    public boolean apply(ExecutableElement input) {
                        return isAnnotationPresent(input, Inject.class);
                    }
                });

        if (injectConstructors.size() > 1) {
            builder.addError(MULTIPLE_INJECT_CONSTRUCTORS, constructorElement);
        }

        ImmutableSet<? extends AnnotationMirror> scopes = getScopes(enclosingElement);
        if (scopes.size() > 1) {
            for (AnnotationMirror scope : scopes) {
                builder.addError(MULTIPLE_SCOPES, enclosingElement, scope);
            }
        }

        return builder.build();
    }
}