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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.producers;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.CLASS;
import dagger.internal.Beta;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
/**
* Annotates a production component or subcomponent to specify its policy when a child component is
* cancelled.
*
* When a future returned from an entry point on a production component is cancelled, the
* component is cancelled: all producers in the component (including those for other entry points)
* are cancelled.
*
*
When a child component is cancelled, its parent component is not cancelled unless the
* parent component is annotated with {@code @CancellationPolicy(fromSubcomponents = PROPAGATE)}. If
* that parent component has a parent (the grandparent of the cancelled child component), it will
* not be cancelled unless it also has a {@code @CancellationPolicy} annotation allowing
* cancellation to propagate to it from subcomponents.
*/
@Documented
@Target(TYPE)
@Retention(CLASS)
@Beta
public @interface CancellationPolicy {
/**
* Defines whether the annotated production component is cancelled when a child component is
* cancelled.
*
*
The default, if no cancellation policy annotation is provided, is {@link
* Propagation#IGNORE}.
*/
Propagation fromSubcomponents();
/**
* Enumeration of the options for what happens to a parent component when one of its child
* components is cancelled.
*/
enum Propagation {
/** Cancel the annotated component when a child component is cancelled. */
PROPAGATE,
/** Do not cancel the annotated component when a child component is cancelled. */
IGNORE
}
}