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/*
* Copyright (C) 2020 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.hilt.android.scopes;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import javax.inject.Scope;
/**
* Scope annotation for bindings that should exist for the life of a a single {@link
* androidx.lifecycle.ViewModel}.
*
* Use this scope annotation when you want to define a dependency in the {@link
* dagger.hilt.android.components.ViewModelComponent} for which a single instance will be provided
* across all other dependencies for a single {@link
* dagger.hilt.android.lifecycle.HiltViewModel}-annotated {@code ViewModel}. Other {@code
* ViewModel}s that request the scoped dependency will receive a different instance. For sharing the
* same instance of a dependency across all {@code ViewModel}s use a scope from one of the parent
* components of {@code dagger.hilt.android.components.ViewModelComponent}, such as {@link
* javax.inject.Singleton} or {@link ActivityRetainedScoped}.
*
*
For example:
*
*
* @Module
* @InstallIn(ViewModelComponent.class)
* public final class ViewModelMovieModule {
* @Provides
* @ViewModelScoped
* public static MovieRepository provideRepo(SavedStateHandle handle) {
* return new MovieRepository(handle.getString("movie-id"));
* }
* }
*
* public final class MovieDetailFetcher {
* @Inject MovieDetailFetcher(MovieRepository movieRepo) {
* // ...
* }
* }
*
* public final class MoviePosterFetcher {
* @Inject MoviePosterFetcher(MovieRepository movieRepo) {
* // ...
* }
* }
*
* @HiltViewModel
* public class MovieViewModel extends ViewModel {
* @Inject
* public MovieViewModel(MovieDetailFetcher detailFetcher, MoviePosterFetcher posterFetcher) {
* // Both detailFetcher and posterFetcher will contain the same instance of
* // the MovieRepository.
* }
* }
*
*
* @see dagger.hilt.android.lifecycle.HiltViewModel
* @see dagger.hilt.android.components.ViewModelComponent
*/
@Scope
@Retention(RetentionPolicy.CLASS)
public @interface ViewModelScoped {}