| /* |
| * Copyright (C) 2016 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.policy; |
| |
| import androidx.lifecycle.Lifecycle; |
| import androidx.lifecycle.Lifecycle.Event; |
| import androidx.lifecycle.LifecycleEventObserver; |
| import androidx.lifecycle.LifecycleOwner; |
| |
| public interface CallbackController<T> { |
| void addCallback(T listener); |
| void removeCallback(T listener); |
| |
| /** |
| * Wrapper to {@link #addCallback(Object)} when a lifecycle is in the resumed state |
| * and {@link #removeCallback(Object)} when not resumed automatically. |
| */ |
| default T observe(LifecycleOwner owner, T listener) { |
| return observe(owner.getLifecycle(), listener); |
| } |
| |
| /** |
| * Wrapper to {@link #addCallback(Object)} when a lifecycle is in the resumed state |
| * and {@link #removeCallback(Object)} when not resumed automatically. |
| */ |
| default T observe(Lifecycle lifecycle, T listener) { |
| lifecycle.addObserver((LifecycleEventObserver) (lifecycleOwner, event) -> { |
| if (event == Event.ON_RESUME) { |
| addCallback(listener); |
| } else if (event == Event.ON_PAUSE) { |
| removeCallback(listener); |
| } |
| }); |
| return listener; |
| } |
| } |