dagger.internal.codegen.ProducerModuleProcessingStep.java Source code

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Here is the source code for dagger.internal.codegen.ProducerModuleProcessingStep.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.BasicAnnotationProcessor.ProcessingStep;
import com.google.auto.common.MoreElements;
import com.google.auto.common.SuperficialValidation;
import com.google.common.base.Function;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.SetMultimap;
import com.google.common.collect.Sets;
import dagger.producers.ProducerModule;
import dagger.producers.Produces;
import java.lang.annotation.Annotation;
import java.util.List;
import java.util.Set;
import javax.annotation.processing.Messager;
import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.util.ElementFilter;

import static com.google.auto.common.MoreElements.isAnnotationPresent;
import static javax.lang.model.element.ElementKind.METHOD;

/**
 * An annotation processor for generating Dagger implementation code based on the
 * {@link ProducerModule} (and {@link Produces}) annotation.
 *
 * @author Jesse Beder
 * @since 2.0
 */
final class ProducerModuleProcessingStep implements ProcessingStep {
    private final Messager messager;
    private final ModuleValidator moduleValidator;
    private final ProducesMethodValidator producesMethodValidator;
    private final ProductionBinding.Factory productionBindingFactory;
    private final ProducerFactoryGenerator factoryGenerator;
    private final Set<Element> processedModuleElements = Sets.newLinkedHashSet();

    ProducerModuleProcessingStep(Messager messager, ModuleValidator moduleValidator,
            ProducesMethodValidator producesMethodValidator, ProductionBinding.Factory productionBindingFactory,
            ProducerFactoryGenerator factoryGenerator) {
        this.messager = messager;
        this.moduleValidator = moduleValidator;
        this.producesMethodValidator = producesMethodValidator;
        this.productionBindingFactory = productionBindingFactory;
        this.factoryGenerator = factoryGenerator;
    }

    @Override
    public Set<Class<? extends Annotation>> annotations() {
        return ImmutableSet.of(Produces.class, ProducerModule.class);
    }

    @Override
    public Set<Element> process(SetMultimap<Class<? extends Annotation>, Element> elementsByAnnotation) {
        // first, check and collect all produces methods
        ImmutableSet.Builder<ExecutableElement> validProducesMethodsBuilder = ImmutableSet.builder();
        for (Element producesElement : elementsByAnnotation.get(Produces.class)) {
            if (producesElement.getKind().equals(METHOD)) {
                ExecutableElement producesMethodElement = (ExecutableElement) producesElement;
                ValidationReport<ExecutableElement> methodReport = producesMethodValidator
                        .validate(producesMethodElement);
                methodReport.printMessagesTo(messager);
                if (methodReport.isClean()) {
                    validProducesMethodsBuilder.add(producesMethodElement);
                }
            }
        }
        ImmutableSet<ExecutableElement> validProducesMethods = validProducesMethodsBuilder.build();

        // process each module
        for (Element moduleElement : Sets.difference(elementsByAnnotation.get(ProducerModule.class),
                processedModuleElements)) {
            if (SuperficialValidation.validateElement(moduleElement)) {
                ValidationReport<TypeElement> report = moduleValidator.validate(MoreElements.asType(moduleElement));
                report.printMessagesTo(messager);

                if (report.isClean()) {
                    ImmutableSet.Builder<ExecutableElement> moduleProducesMethodsBuilder = ImmutableSet.builder();
                    List<ExecutableElement> moduleMethods = ElementFilter
                            .methodsIn(moduleElement.getEnclosedElements());
                    for (ExecutableElement methodElement : moduleMethods) {
                        if (isAnnotationPresent(methodElement, Produces.class)) {
                            moduleProducesMethodsBuilder.add(methodElement);
                        }
                    }
                    ImmutableSet<ExecutableElement> moduleProducesMethods = moduleProducesMethodsBuilder.build();

                    if (Sets.difference(moduleProducesMethods, validProducesMethods).isEmpty()) {
                        // all of the produces methods in this module are valid!
                        // time to generate some factories!
                        ImmutableSet<ProductionBinding> bindings = FluentIterable.from(moduleProducesMethods)
                                .transform(new Function<ExecutableElement, ProductionBinding>() {
                                    @Override
                                    public ProductionBinding apply(ExecutableElement producesMethod) {
                                        return productionBindingFactory.forProducesMethod(producesMethod,
                                                producesMethod.getEnclosingElement().asType());
                                    }
                                }).toSet();

                        try {
                            for (ProductionBinding binding : bindings) {
                                factoryGenerator.generate(binding);
                            }
                        } catch (SourceFileGenerationException e) {
                            e.printMessageTo(messager);
                        }
                    }
                }

                processedModuleElements.add(moduleElement);
            }
        }
        return ImmutableSet.of();
    }
}