1 /** 2 * Copyright (C) 2021 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 android.view; 18 19 import android.annotation.CallbackExecutor; 20 import android.annotation.NonNull; 21 import android.os.Binder; 22 import android.os.Handler; 23 import android.os.Looper; 24 import android.os.RemoteException; 25 import android.os.SystemProperties; 26 import android.util.ArrayMap; 27 import android.util.Log; 28 29 import com.android.internal.util.Preconditions; 30 31 import java.util.concurrent.Executor; 32 import java.util.function.Consumer; 33 34 /** 35 * Class that holds all registered {@link CrossWindowBlurEnabledListener}s. It listens 36 * for updates from the WindowManagerService and updates all registered listeners. 37 * @hide 38 */ 39 public final class CrossWindowBlurListeners { 40 private static final String TAG = "CrossWindowBlurListeners"; 41 42 // property for background blur support in surface flinger 43 private static final String BLUR_PROPERTY = "ro.surface_flinger.supports_background_blur"; 44 public static final boolean CROSS_WINDOW_BLUR_SUPPORTED = 45 SystemProperties.getBoolean(BLUR_PROPERTY, false); 46 47 private static volatile CrossWindowBlurListeners sInstance; 48 private static final Object sLock = new Object(); 49 50 private final BlurEnabledListenerInternal mListenerInternal = new BlurEnabledListenerInternal(); 51 private final ArrayMap<Consumer<Boolean>, Executor> mListeners = new ArrayMap(); 52 private final Handler mMainHandler = new Handler(Looper.getMainLooper()); 53 private boolean mInternalListenerAttached = false; 54 private boolean mCrossWindowBlurEnabled; 55 CrossWindowBlurListeners()56 private CrossWindowBlurListeners() {} 57 58 /** 59 * Returns a CrossWindowBlurListeners instance 60 */ getInstance()61 public static CrossWindowBlurListeners getInstance() { 62 CrossWindowBlurListeners instance = sInstance; 63 if (instance == null) { 64 65 synchronized (sLock) { 66 instance = sInstance; 67 if (instance == null) { 68 instance = new CrossWindowBlurListeners(); 69 sInstance = instance; 70 } 71 } 72 } 73 return instance; 74 } 75 isCrossWindowBlurEnabled()76 public boolean isCrossWindowBlurEnabled() { 77 synchronized (sLock) { 78 attachInternalListenerIfNeededLocked(); 79 return mCrossWindowBlurEnabled; 80 } 81 } 82 addListener(@onNull @allbackExecutor Executor executor, @NonNull Consumer<Boolean> listener)83 public void addListener(@NonNull @CallbackExecutor Executor executor, 84 @NonNull Consumer<Boolean> listener) { 85 Preconditions.checkNotNull(listener, "listener cannot be null"); 86 Preconditions.checkNotNull(executor, "executor cannot be null"); 87 88 synchronized (sLock) { 89 attachInternalListenerIfNeededLocked(); 90 91 mListeners.put(listener, executor); 92 notifyListener(listener, executor, mCrossWindowBlurEnabled); 93 } 94 } 95 96 removeListener(Consumer<Boolean> listener)97 public void removeListener(Consumer<Boolean> listener) { 98 Preconditions.checkNotNull(listener, "listener cannot be null"); 99 100 synchronized (sLock) { 101 mListeners.remove(listener); 102 103 if (mInternalListenerAttached && mListeners.size() == 0) { 104 try { 105 WindowManagerGlobal.getWindowManagerService() 106 .unregisterCrossWindowBlurEnabledListener(mListenerInternal); 107 mInternalListenerAttached = false; 108 } catch (RemoteException e) { 109 Log.d(TAG, "Could not unregister ICrossWindowBlurEnabledListener"); 110 } 111 } 112 } 113 } 114 attachInternalListenerIfNeededLocked()115 private void attachInternalListenerIfNeededLocked() { 116 if (!mInternalListenerAttached) { 117 try { 118 mCrossWindowBlurEnabled = WindowManagerGlobal.getWindowManagerService() 119 .registerCrossWindowBlurEnabledListener(mListenerInternal); 120 mInternalListenerAttached = true; 121 } catch (RemoteException e) { 122 Log.d(TAG, "Could not register ICrossWindowBlurEnabledListener"); 123 } 124 } 125 } 126 notifyListener(Consumer<Boolean> listener, Executor executor, boolean enabled)127 private void notifyListener(Consumer<Boolean> listener, Executor executor, boolean enabled) { 128 executor.execute(() -> listener.accept(enabled)); 129 } 130 131 private final class BlurEnabledListenerInternal extends ICrossWindowBlurEnabledListener.Stub { 132 @Override onCrossWindowBlurEnabledChanged(boolean enabled)133 public void onCrossWindowBlurEnabledChanged(boolean enabled) { 134 synchronized (sLock) { 135 mCrossWindowBlurEnabled = enabled; 136 137 final long token = Binder.clearCallingIdentity(); 138 try { 139 for (int i = 0; i < mListeners.size(); i++) { 140 notifyListener(mListeners.keyAt(i), mListeners.valueAt(i), enabled); 141 } 142 } finally { 143 Binder.restoreCallingIdentity(token); 144 } 145 } 146 } 147 } 148 } 149