1 /* 2 * Copyright (C) 2025 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.launcher3.util 18 19 import androidx.lifecycle.DefaultLifecycleObserver 20 import androidx.lifecycle.LifecycleOwner 21 import com.android.launcher3.util.Executors.MAIN_EXECUTOR 22 import java.util.Collections 23 import java.util.WeakHashMap 24 25 /** 26 * Utility class which maintains a list of cleanup callbacks using weak-references. These callbacks 27 * are called when the [owner] is destroyed, but can also be cleared when the caller is GCed 28 */ 29 class WeakCleanupSet(owner: LifecycleOwner) { 30 31 private val callbacks = Collections.newSetFromMap<OnOwnerDestroyedCallback>(WeakHashMap()) 32 private var destroyed = false 33 34 init { <lambda>null35 MAIN_EXECUTOR.execute { 36 owner.lifecycle.addObserver( 37 object : DefaultLifecycleObserver { 38 39 override fun onDestroy(owner: LifecycleOwner) { 40 destroyed = true 41 callbacks.forEach { it.onOwnerDestroyed() } 42 } 43 } 44 ) 45 } 46 } 47 addOnOwnerDestroyedCallbacknull48 fun addOnOwnerDestroyedCallback(callback: OnOwnerDestroyedCallback) { 49 if (destroyed) callback.onOwnerDestroyed() else callbacks.add(callback) 50 } 51 52 /** Callback when the owner is destroyed */ 53 interface OnOwnerDestroyedCallback { onOwnerDestroyednull54 fun onOwnerDestroyed() 55 } 56 } 57