1 /* 2 * Copyright (C) 2022 The Dagger Authors. 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 dagger.hilt.android.internal.lifecycle; 18 19 import androidx.annotation.NonNull; 20 import dagger.hilt.android.ActivityRetainedLifecycle; 21 import dagger.hilt.android.ViewModelLifecycle; 22 import dagger.hilt.android.internal.ThreadUtil; 23 import dagger.hilt.android.lifecycle.RetainedLifecycle; 24 import java.util.HashSet; 25 import java.util.Set; 26 27 /** Internal implementation. Do not use. */ 28 public final class RetainedLifecycleImpl 29 implements ActivityRetainedLifecycle, 30 ViewModelLifecycle { 31 32 private final Set<RetainedLifecycle.OnClearedListener> listeners = new HashSet<>(); 33 private boolean onClearedDispatched = false; 34 RetainedLifecycleImpl()35 public RetainedLifecycleImpl() {} 36 37 @Override addOnClearedListener(@onNull RetainedLifecycle.OnClearedListener listener)38 public void addOnClearedListener(@NonNull RetainedLifecycle.OnClearedListener listener) { 39 ThreadUtil.ensureMainThread(); 40 throwIfOnClearedDispatched(); 41 listeners.add(listener); 42 } 43 44 @Override removeOnClearedListener(@onNull RetainedLifecycle.OnClearedListener listener)45 public void removeOnClearedListener(@NonNull RetainedLifecycle.OnClearedListener listener) { 46 ThreadUtil.ensureMainThread(); 47 throwIfOnClearedDispatched(); 48 listeners.remove(listener); 49 } 50 dispatchOnCleared()51 public void dispatchOnCleared() { 52 ThreadUtil.ensureMainThread(); 53 onClearedDispatched = true; 54 for (RetainedLifecycle.OnClearedListener listener : listeners) { 55 listener.onCleared(); 56 } 57 } 58 throwIfOnClearedDispatched()59 private void throwIfOnClearedDispatched() { 60 if (onClearedDispatched) { 61 throw new IllegalStateException( 62 "There was a race between the call to add/remove an OnClearedListener and onCleared(). " 63 + "This can happen when posting to the Main thread from a background thread, " 64 + "which is not supported."); 65 } 66 } 67 } 68