| /* |
| * Copyright (C) 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 com.android.systemui.statusbar.notification.people |
| |
| /** Boundary between a View and data pipeline, as seen by the pipeline. */ |
| interface DataListener<in T> { |
| fun onDataChanged(data: T) |
| } |
| |
| /** Convert all data using the given [mapper] before invoking this [DataListener]. */ |
| fun <S, T> DataListener<T>.contraMap(mapper: (S) -> T): DataListener<S> = object : DataListener<S> { |
| override fun onDataChanged(data: S) = onDataChanged(mapper(data)) |
| } |
| |
| /** Boundary between a View and data pipeline, as seen by the View. */ |
| interface DataSource<out T> { |
| fun setListener(listener: DataListener<T>) |
| } |
| |
| /** Transform all data coming out of this [DataSource] using the given [mapper]. */ |
| fun <S, T> DataSource<S>.map(mapper: (S) -> T): DataSource<T> = object : DataSource<T> { |
| override fun setListener(listener: DataListener<T>) = setListener(listener.contraMap(mapper)) |
| } |