content: /*
   * Copyright (C) 2010 ZXing authors
   *
   * 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 com.google.zxing.decoding;
  
  import android.app.Activity;
  
  import java.util.concurrent.Executors;
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.ScheduledFuture;
  import java.util.concurrent.ThreadFactory;
  import java.util.concurrent.TimeUnit;
  
  /**
   * Finishes an activity after a period of inactivity.
   */
  public final class InactivityTimer {
  
      private static final int INACTIVITY_DELAY_SECONDS = 5 * 60;
  
      private final ScheduledExecutorService inactivityTimer =
              Executors.newSingleThreadScheduledExecutor(new DaemonThreadFactory());
      private final Activity activity;
      private ScheduledFuture<?> inactivityFuture = null;
  
      public InactivityTimer(Activity activity) {
          this.activity = activity;
          onActivity();
      }
  
      public void onActivity() {
          cancel();
          inactivityFuture = inactivityTimer.schedule(new FinishListener(activity),
                  INACTIVITY_DELAY_SECONDS,
                  TimeUnit.SECONDS);
      }
  
      private void cancel() {
          if (inactivityFuture != null) {
              inactivityFuture.cancel(true);
              inactivityFuture = null;
          }
      }
  
      public void shutdown() {
          cancel();
          inactivityTimer.shutdown();
      }
  
      private static final class DaemonThreadFactory implements ThreadFactory {
          public Thread newThread(Runnable runnable) {
              Thread thread = new Thread(runnable);
              thread.setDaemon(true);
              return thread;
          }
      }
  
  }
  