| /* |
| * Copyright (C) 2017 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 android.arch.core.executor; |
| |
| import android.support.annotation.NonNull; |
| import android.support.annotation.Nullable; |
| import android.support.annotation.RestrictTo; |
| |
| import java.util.concurrent.Executor; |
| |
| /** |
| * A static class that serves as a central point to execute common tasks. |
| * <p> |
| * |
| * @hide This API is not final. |
| */ |
| @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP) |
| public class ArchTaskExecutor extends TaskExecutor { |
| private static volatile ArchTaskExecutor sInstance; |
| |
| @NonNull |
| private TaskExecutor mDelegate; |
| |
| @NonNull |
| private TaskExecutor mDefaultTaskExecutor; |
| |
| @NonNull |
| private static final Executor sMainThreadExecutor = new Executor() { |
| @Override |
| public void execute(Runnable command) { |
| getInstance().postToMainThread(command); |
| } |
| }; |
| |
| @NonNull |
| private static final Executor sIOThreadExecutor = new Executor() { |
| @Override |
| public void execute(Runnable command) { |
| getInstance().executeOnDiskIO(command); |
| } |
| }; |
| |
| private ArchTaskExecutor() { |
| mDefaultTaskExecutor = new DefaultTaskExecutor(); |
| mDelegate = mDefaultTaskExecutor; |
| } |
| |
| /** |
| * Returns an instance of the task executor. |
| * |
| * @return The singleton ArchTaskExecutor. |
| */ |
| public static ArchTaskExecutor getInstance() { |
| if (sInstance != null) { |
| return sInstance; |
| } |
| synchronized (ArchTaskExecutor.class) { |
| if (sInstance == null) { |
| sInstance = new ArchTaskExecutor(); |
| } |
| } |
| return sInstance; |
| } |
| |
| /** |
| * Sets a delegate to handle task execution requests. |
| * <p> |
| * If you have a common executor, you can set it as the delegate and App Toolkit components will |
| * use your executors. You may also want to use this for your tests. |
| * <p> |
| * Calling this method with {@code null} sets it to the default TaskExecutor. |
| * |
| * @param taskExecutor The task executor to handle task requests. |
| */ |
| public void setDelegate(@Nullable TaskExecutor taskExecutor) { |
| mDelegate = taskExecutor == null ? mDefaultTaskExecutor : taskExecutor; |
| } |
| |
| @Override |
| public void executeOnDiskIO(Runnable runnable) { |
| mDelegate.executeOnDiskIO(runnable); |
| } |
| |
| @Override |
| public void postToMainThread(Runnable runnable) { |
| mDelegate.postToMainThread(runnable); |
| } |
| |
| @NonNull |
| public static Executor getMainThreadExecutor() { |
| return sMainThreadExecutor; |
| } |
| |
| @NonNull |
| public static Executor getIOThreadExecutor() { |
| return sIOThreadExecutor; |
| } |
| |
| @Override |
| public boolean isMainThread() { |
| return mDelegate.isMainThread(); |
| } |
| } |