1 /* 2 * Copyright (C) 2010 ZXing 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 com.google.zxing.client.android; 18 19 import android.app.Activity; 20 import android.content.BroadcastReceiver; 21 import android.content.Context; 22 import android.content.Intent; 23 import android.content.IntentFilter; 24 25 import java.util.concurrent.Executors; 26 import java.util.concurrent.RejectedExecutionException; 27 import java.util.concurrent.ScheduledExecutorService; 28 import java.util.concurrent.ScheduledFuture; 29 import java.util.concurrent.ThreadFactory; 30 import java.util.concurrent.TimeUnit; 31 32 /** 33 * Finishes an activity after a period of inactivity if the device is on battery power. 34 */ 35 final class InactivityTimer { 36 37 private static final int INACTIVITY_DELAY_SECONDS = 5 * 60; 38 39 private final ScheduledExecutorService inactivityTimer = 40 Executors.newSingleThreadScheduledExecutor(new DaemonThreadFactory()); 41 private final Activity activity; 42 private ScheduledFuture<?> inactivityFuture = null; 43 private final BroadcastReceiver powerStatusReceiver = new PowerStatusReceiver(); 44 45 InactivityTimer(Activity activity) { 46 this.activity = activity; 47 onActivity(); 48 } 49 50 void onActivity() { 51 cancel(); 52 if (!inactivityTimer.isShutdown()) { 53 try { 54 inactivityFuture = inactivityTimer.schedule(new FinishListener(activity), 55 INACTIVITY_DELAY_SECONDS, 56 TimeUnit.SECONDS); 57 } catch (RejectedExecutionException ree) { 58 // surprising, but could be normal if for some reason the implementation just doesn't 59 // think it can shcedule again. Since this time-out is non-essential, just forget it 60 } 61 } 62 } 63 64 public void onPause() { 65 cancel(); 66 activity.unregisterReceiver(powerStatusReceiver); 67 } 68 69 public void onResume(){ 70 activity.registerReceiver(powerStatusReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED)); 71 onActivity(); 72 } 73 74 private void cancel() { 75 ScheduledFuture<?> future = inactivityFuture; 76 if (future != null) { 77 future.cancel(true); 78 inactivityFuture = null; 79 } 80 } 81 82 void shutdown() { 83 cancel(); 84 inactivityTimer.shutdown(); 85 } 86 87 private static final class DaemonThreadFactory implements ThreadFactory { 88 public Thread newThread(Runnable runnable) { 89 Thread thread = new Thread(runnable); 90 thread.setDaemon(true); 91 return thread; 92 } 93 } 94 95 private final class PowerStatusReceiver extends BroadcastReceiver { 96 @Override 97 public void onReceive(Context context, Intent intent){ 98 if (Intent.ACTION_BATTERY_CHANGED.equals(intent.getAction())) { 99 // 0 indicates that we're on battery 100 // In Android 2.0+, use BatteryManager.EXTRA_PLUGGED 101 int batteryPlugged = intent.getIntExtra("plugged", -1); 102 if (batteryPlugged > 0) { 103 InactivityTimer.this.cancel(); 104 } 105 } 106 } 107 } 108 109 } 110
