1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.systemui.util; 18 19 import static androidx.lifecycle.Lifecycle.State.DESTROYED; 20 import static androidx.lifecycle.Lifecycle.State.RESUMED; 21 22 import android.view.View; 23 import android.view.View.OnAttachStateChangeListener; 24 25 import androidx.annotation.NonNull; 26 import androidx.lifecycle.Lifecycle; 27 import androidx.lifecycle.LifecycleOwner; 28 import androidx.lifecycle.LifecycleRegistry; 29 30 /** 31 * Tools for generating lifecycle from sysui objects. 32 */ 33 public class SysuiLifecycle { 34 SysuiLifecycle()35 private SysuiLifecycle() { 36 } 37 38 /** 39 * Get a lifecycle that will be put into the resumed state when the view is attached 40 * and goes to the destroyed state when the view is detached. 41 */ viewAttachLifecycle(View v)42 public static LifecycleOwner viewAttachLifecycle(View v) { 43 return new ViewLifecycle(v); 44 } 45 46 private static class ViewLifecycle implements LifecycleOwner, OnAttachStateChangeListener { 47 private final LifecycleRegistry mLifecycle = new LifecycleRegistry(this); 48 ViewLifecycle(View v)49 ViewLifecycle(View v) { 50 v.addOnAttachStateChangeListener(this); 51 if (v.isAttachedToWindow()) { 52 mLifecycle.markState(RESUMED); 53 } 54 } 55 56 @NonNull 57 @Override getLifecycle()58 public Lifecycle getLifecycle() { 59 return mLifecycle; 60 } 61 62 @Override onViewAttachedToWindow(View v)63 public void onViewAttachedToWindow(View v) { 64 mLifecycle.markState(RESUMED); 65 } 66 67 @Override onViewDetachedFromWindow(View v)68 public void onViewDetachedFromWindow(View v) { 69 mLifecycle.markState(DESTROYED); 70 } 71 } 72 } 73