dagger2.internal.codegen.ModuleProcessingStep.java Source code

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Here is the source code for dagger2.internal.codegen.ModuleProcessingStep.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 dagger2.internal.codegen;

import com.google.auto.common.BasicAnnotationProcessor;
import com.google.auto.common.MoreElements;
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 dagger2.Module;
import dagger2.Provides;
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 Module}
 * (and {@link Provides}) annotation.
 *
 * @author Gregory Kick
 * @since 2.0
 */
final class ModuleProcessingStep implements BasicAnnotationProcessor.ProcessingStep {
    private final Messager messager;
    private final ModuleValidator moduleValidator;
    private final ProvidesMethodValidator providesMethodValidator;
    private final ProvisionBinding.Factory provisionBindingFactory;
    private final FactoryGenerator factoryGenerator;
    private final Set<Element> processedModuleElements = Sets.newLinkedHashSet();

    ModuleProcessingStep(Messager messager, ModuleValidator moduleValidator,
            ProvidesMethodValidator providesMethodValidator, ProvisionBinding.Factory provisionBindingFactory,
            FactoryGenerator factoryGenerator) {
        this.messager = messager;
        this.moduleValidator = moduleValidator;
        this.providesMethodValidator = providesMethodValidator;
        this.provisionBindingFactory = provisionBindingFactory;
        this.factoryGenerator = factoryGenerator;
    }

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

    @Override
    public void process(SetMultimap<Class<? extends Annotation>, Element> elementsByAnnotation) {
        // first, check and collect all provides methods
        ImmutableSet.Builder<ExecutableElement> validProvidesMethodsBuilder = ImmutableSet.builder();
        for (Element providesElement : elementsByAnnotation.get(Provides.class)) {
            if (providesElement.getKind().equals(METHOD)) {
                ExecutableElement providesMethodElement = (ExecutableElement) providesElement;
                ValidationReport<ExecutableElement> methodReport = providesMethodValidator
                        .validate(providesMethodElement);
                methodReport.printMessagesTo(messager);
                if (methodReport.isClean()) {
                    validProvidesMethodsBuilder.add(providesMethodElement);
                }
            }
        }
        ImmutableSet<ExecutableElement> validProvidesMethods = validProvidesMethodsBuilder.build();

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

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

                if (Sets.difference(moduleProvidesMethods, validProvidesMethods).isEmpty()) {
                    // all of the provides methods in this module are valid!
                    // time to generate some factories!
                    ImmutableSet<ProvisionBinding> bindings = FluentIterable.from(moduleProvidesMethods)
                            .transform(new Function<ExecutableElement, ProvisionBinding>() {
                                @Override
                                public ProvisionBinding apply(ExecutableElement providesMethod) {
                                    return provisionBindingFactory.forProvidesMethod(providesMethod,
                                            providesMethod.getEnclosingElement().asType());
                                }
                            }).toSet();

                    try {
                        for (ProvisionBinding binding : bindings) {
                            factoryGenerator.generate(binding);
                        }
                    } catch (SourceFileGenerationException e) {
                        e.printMessageTo(messager);
                    }
                }
            }
            processedModuleElements.add(moduleElement);
        }
    }
}