WrapperPositionalDataSource.kt
/*
* Copyright 2019 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
import androidx.arch.core.util.Function
@Suppress("DEPRECATION")
internal class WrapperPositionalDataSource<A : Any, B : Any>(
private val source: PositionalDataSource<A>,
val listFunction: Function<List<A>, List<B>>
) : PositionalDataSource<B>() {
override val isInvalid
get() = source.isInvalid
override fun addInvalidatedCallback(onInvalidatedCallback: InvalidatedCallback) {
source.addInvalidatedCallback(onInvalidatedCallback)
}
override fun removeInvalidatedCallback(onInvalidatedCallback: InvalidatedCallback) {
source.removeInvalidatedCallback(onInvalidatedCallback)
}
override fun invalidate() = source.invalidate()
override fun loadInitial(params: LoadInitialParams, callback: LoadInitialCallback<B>) {
source.loadInitial(
params,
object : LoadInitialCallback<A>() {
override fun onResult(data: List<A>, position: Int, totalCount: Int) =
callback.onResult(convert(listFunction, data), position, totalCount)
override fun onResult(data: List<A>, position: Int) =
callback.onResult(convert(listFunction, data), position)
}
)
}
override fun loadRange(params: LoadRangeParams, callback: LoadRangeCallback<B>) {
source.loadRange(
params,
object : LoadRangeCallback<A>() {
override fun onResult(data: List<A>) =
callback.onResult(convert(listFunction, data))
}
)
}
}