1 /* 2 * Copyright (C) 2015 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.camera.one.v2.commands; 18 19 import com.google.common.util.concurrent.Futures; 20 21 import java.util.concurrent.Future; 22 23 import javax.annotation.Nonnull; 24 import javax.annotation.ParametersAreNonnullByDefault; 25 import javax.annotation.concurrent.ThreadSafe; 26 27 /** 28 * Converts a {@link CameraCommand} into a {@link Runnable} which interrupts and 29 * restarts the command if it was already running. 30 */ 31 @ThreadSafe 32 @ParametersAreNonnullByDefault 33 public final class ResettingRunnableCameraCommand implements Runnable { 34 private final CameraCommandExecutor mExecutor; 35 private final CameraCommand mCommand; 36 private final Object mLock; 37 38 /** 39 * The future corresponding to any currently-executing command. 40 */ 41 @Nonnull 42 private Future<?> mInProgressCommand; 43 44 public ResettingRunnableCameraCommand(CameraCommandExecutor executor, CameraCommand command) { 45 mExecutor = executor; 46 mCommand = command; 47 mLock = new Object(); 48 mInProgressCommand = Futures.immediateFuture(new Object()); 49 } 50 51 @Override 52 public void run() { 53 synchronized (mLock) { 54 // Cancel, via interruption, the already-running command, one has 55 // been started and has not yet completed. 56 mInProgressCommand.cancel(true /* mayInterruptIfRunning */); 57 mInProgressCommand = mExecutor.execute(mCommand); 58 } 59 } 60 } 61
