| /* |
| * Copyright 2022 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. |
| */ |
| |
| package androidx.paging.testing |
| |
| import androidx.annotation.VisibleForTesting |
| import androidx.paging.InvalidatingPagingSourceFactory |
| import androidx.paging.LoadType.REFRESH |
| import androidx.paging.Pager |
| import androidx.paging.PagingSource |
| import androidx.paging.PagingSourceFactory |
| import kotlin.jvm.JvmSuppressWildcards |
| import kotlinx.coroutines.CoroutineScope |
| import kotlinx.coroutines.flow.Flow |
| import kotlinx.coroutines.launch |
| |
| /** |
| * Returns a [PagingSourceFactory] that creates [PagingSource] instances. |
| * |
| * Can be used as the pagingSourceFactory when constructing a [Pager] in tests. The same factory |
| * should be reused within the lifetime of a ViewModel. |
| * |
| * Extension method on a [Flow] of list that represents the data source, with each static list |
| * representing a generation of data from which a [PagingSource] will load from. With every emission |
| * to the flow, the current [PagingSource] will be invalidated, thereby triggering a new generation |
| * of Paged data. |
| * |
| * Supports multiple factories and thus multiple collection on the same flow. |
| * |
| * @param coroutineScope the CoroutineScope to collect from the Flow of list. |
| */ |
| @VisibleForTesting |
| public fun <Value : Any> Flow<@JvmSuppressWildcards List<Value>>.asPagingSourceFactory( |
| coroutineScope: CoroutineScope |
| ): PagingSourceFactory<Int, Value> { |
| |
| var data: List<Value>? = null |
| |
| val factory = InvalidatingPagingSourceFactory { |
| val dataSource = data ?: emptyList() |
| |
| @Suppress("UNCHECKED_CAST") StaticListPagingSource(dataSource) |
| } |
| |
| coroutineScope.launch { |
| collect { list -> |
| data = list |
| factory.invalidate() |
| } |
| } |
| |
| return factory |
| } |
| |
| /** |
| * Returns a [PagingSourceFactory] that creates [PagingSource] instances. |
| * |
| * Can be used as the pagingSourceFactory when constructing a [Pager] in tests. The same factory |
| * should be reused within the lifetime of a ViewModel. |
| * |
| * Extension method on a [List] of data from which a [PagingSource] will load from. While this |
| * factory supports multi-generational operations such as [REFRESH], it does not support updating |
| * the data source. This means any PagingSources generated by the same factory will load from the |
| * exact same list of data. |
| */ |
| @VisibleForTesting |
| public fun <Value : Any> List<Value>.asPagingSourceFactory(): PagingSourceFactory<Int, Value> = |
| PagingSourceFactory { |
| StaticListPagingSource(this) |
| } |