HiltNavBackStackEntry.kt
/*
* Copyright 2021 The Android Open Source Project
*
* 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.
*/
@file:JvmName("HiltViewModelFactory")
package androidx.hilt.navigation
import android.app.Activity
import android.content.Context
import android.content.ContextWrapper
import androidx.lifecycle.ViewModelProvider
import androidx.navigation.NavBackStackEntry
import dagger.hilt.EntryPoint
import dagger.hilt.InstallIn
import dagger.hilt.android.EntryPointAccessors
import dagger.hilt.android.components.ActivityComponent
import dagger.hilt.android.internal.builders.ViewModelComponentBuilder
import dagger.hilt.android.internal.lifecycle.HiltViewModelFactory
import dagger.hilt.android.internal.lifecycle.HiltViewModelMap
@EntryPoint
@InstallIn(ActivityComponent::class)
internal interface NavBackStackEntryViewModelFactoryEntryPoint {
@HiltViewModelMap.KeySet
fun getViewModelKeys(): Set<String>
fun getViewModelComponentBuilder(): ViewModelComponentBuilder
}
/**
* Creates a [ViewModelProvider.Factory] to get
* [dagger.hilt.android.lifecycle.HiltViewModel] annotated `ViewModel` from a
* [NavBackStackEntry].
*
* @param context the activity context.
* @param navBackStackEntry the navigation back stack entry.
* @return the factory.
* @throws IllegalStateException if the context given is not an activity.
*/
@JvmName("create")
public fun HiltViewModelFactory(
context: Context,
navBackStackEntry: NavBackStackEntry
): ViewModelProvider.Factory {
val activity = context.let {
var ctx = it
while (ctx is ContextWrapper) {
if (ctx is Activity) {
return@let ctx
}
ctx = ctx.baseContext
}
throw IllegalStateException(
"Expected an activity context for creating a HiltViewModelFactory for a " +
"NavBackStackEntry but instead found: $ctx"
)
}
val entryPoint = EntryPointAccessors.fromActivity(
activity,
NavBackStackEntryViewModelFactoryEntryPoint::class.java
)
return HiltViewModelFactory(
navBackStackEntry,
navBackStackEntry.arguments,
entryPoint.getViewModelKeys(),
navBackStackEntry.defaultViewModelProviderFactory,
entryPoint.getViewModelComponentBuilder()
)
}