dagger.internal.codegen.writing.ProducerEntryPointView Maven / Gradle / Ivy
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/*
* Copyright (C) 2018 The Dagger Authors.
*
* 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.writing;
import static dagger.internal.codegen.writing.ComponentImplementation.FieldSpecKind.FRAMEWORK_FIELD;
import static dagger.internal.codegen.xprocessing.XElements.getSimpleName;
import static javax.lang.model.element.Modifier.PRIVATE;
import com.squareup.javapoet.ClassName;
import com.squareup.javapoet.CodeBlock;
import com.squareup.javapoet.FieldSpec;
import com.squareup.javapoet.TypeName;
import dagger.internal.codegen.binding.ComponentDescriptor.ComponentMethodDescriptor;
import dagger.internal.codegen.javapoet.Expression;
import dagger.internal.codegen.javapoet.TypeNames;
import dagger.internal.codegen.langmodel.DaggerTypes;
import dagger.internal.codegen.writing.ComponentImplementation.ShardImplementation;
import dagger.producers.Producer;
import dagger.producers.internal.CancellationListener;
import dagger.producers.internal.Producers;
import dagger.spi.model.RequestKind;
import java.util.Optional;
import javax.lang.model.type.TypeMirror;
/**
* A factory of {@linkplain Producers#entryPointViewOf(Producer, CancellationListener) entry point
* views} of {@link Producer}s.
*/
final class ProducerEntryPointView {
private final ShardImplementation shardImplementation;
private final DaggerTypes types;
ProducerEntryPointView(ShardImplementation shardImplementation, DaggerTypes types) {
this.shardImplementation = shardImplementation;
this.types = types;
}
/**
* Returns an expression for an {@linkplain Producers#entryPointViewOf(Producer,
* CancellationListener) entry point view} of a producer if the component method returns a {@link
* Producer} or {@link com.google.common.util.concurrent.ListenableFuture}.
*
* This is intended to be a replacement implementation for {@link
* dagger.internal.codegen.writing.RequestRepresentation#getDependencyExpressionForComponentMethod(ComponentMethodDescriptor,
* ComponentImplementation)}, and in cases where {@link Optional#empty()} is returned, callers
* should call {@code super.getDependencyExpressionForComponentMethod()}.
*/
Optional getProducerEntryPointField(
RequestRepresentation producerExpression,
ComponentMethodDescriptor componentMethod,
ClassName requestingClass) {
if (shardImplementation.componentDescriptor().isProduction()
&& (componentMethod.dependencyRequest().get().kind().equals(RequestKind.FUTURE)
|| componentMethod.dependencyRequest().get().kind().equals(RequestKind.PRODUCER))) {
MemberSelect field = createField(producerExpression, componentMethod);
return Optional.of(
Expression.create(fieldType(componentMethod), field.getExpressionFor(requestingClass)));
} else {
// If the component isn't a production component, it won't implement CancellationListener and
// as such we can't create an entry point. But this binding must also just be a Producer from
// Provider anyway in that case, so there shouldn't be an issue.
// TODO(b/116855531): Is it really intended that a non-production component can have Producer
// entry points?
return Optional.empty();
}
}
private MemberSelect createField(
RequestRepresentation producerExpression, ComponentMethodDescriptor componentMethod) {
// TODO(cgdecker): Use a FrameworkFieldInitializer for this?
// Though I don't think we need the once-only behavior of that, since I think
// getComponentMethodImplementation will only be called once anyway
String methodName = getSimpleName(componentMethod.methodElement());
FieldSpec field =
FieldSpec.builder(
TypeName.get(fieldType(componentMethod)),
shardImplementation.getUniqueFieldName(methodName + "EntryPoint"),
PRIVATE)
.build();
shardImplementation.addField(FRAMEWORK_FIELD, field);
CodeBlock fieldInitialization =
CodeBlock.of(
"this.$N = $T.entryPointViewOf($L, $L);",
field,
Producers.class,
producerExpression.getDependencyExpression(shardImplementation.name()).codeBlock(),
// Always pass in the componentShard reference here rather than the owning shard for
// this key because this needs to be the root CancellationListener.
shardImplementation.isComponentShard()
? "this"
: shardImplementation
.getComponentImplementation()
.getComponentShard()
.shardFieldReference());
shardImplementation.addInitialization(fieldInitialization);
return MemberSelect.localField(shardImplementation, field.name);
}
// TODO(cgdecker): Can we use producerExpression.getDependencyExpression().type() instead of
// needing to (re)compute this?
private TypeMirror fieldType(ComponentMethodDescriptor componentMethod) {
return types.wrapType(
componentMethod.dependencyRequest().get().key().type().java(), TypeNames.PRODUCER);
}
}