/**
   * Stop the bundle. Nothing to stop for now.
   *
   * @param bundleContext <tt>BundleContext</tt> provided by OSGi framework
   * @throws Exception if something goes wrong during stop
   */
  public void stop(BundleContext bundleContext) throws Exception {
    if (logger.isDebugEnabled()) logger.debug("Update checker [STOPPED]");

    if (mUpdateExecutor != null) {
      mUpdateExecutor.shutdown();
      mUpdateExecutor = null;
    }
  }
  /**
   * The dependent service is available and the bundle will start.
   *
   * @param dependentService the UIService this activator is waiting.
   */
  @Override
  public void start(Object dependentService) {
    if (logger.isDebugEnabled()) logger.debug("Update checker [STARTED]");

    ConfigurationService cfg = getConfiguration();

    if (OSUtils.IS_WINDOWS) {
      updateService = new Update();

      bundleContext.registerService(UpdateService.class.getName(), updateService, null);

      // Register the "Check for Updates" menu item if
      // the "Check for Updates" property isn't disabled.
      if (!cfg.getBoolean(CHECK_FOR_UPDATES_MENU_DISABLED_PROP, false)) {
        // Register the "Check for Updates" menu item.
        CheckForUpdatesMenuItemComponent checkForUpdatesMenuItemComponent =
            new CheckForUpdatesMenuItemComponent(Container.CONTAINER_HELP_MENU);

        Hashtable<String, String> toolsMenuFilter = new Hashtable<String, String>();
        toolsMenuFilter.put(Container.CONTAINER_ID, Container.CONTAINER_HELP_MENU.getID());

        bundleContext.registerService(
            PluginComponent.class.getName(), checkForUpdatesMenuItemComponent, toolsMenuFilter);
      }

      // Check for software update upon startup if enabled.
      if (cfg.getBoolean(UPDATE_ENABLED, true)) updateService.checkForUpdates(false);
    }

    if (cfg.getBoolean(CHECK_FOR_UPDATES_DAILY_ENABLED_PROP, false)) {
      logger.info("Scheduled update checking enabled");

      // Schedule a "check for updates" task that will run once a day
      int hoursToWait = calcHoursToWait();
      Runnable updateRunnable =
          new Runnable() {
            public void run() {
              logger.debug("Performing scheduled update check");
              getUpdateService().checkForUpdates(false);
            }
          };

      mUpdateExecutor = Executors.newSingleThreadScheduledExecutor();
      mUpdateExecutor.scheduleAtFixedRate(
          updateRunnable, hoursToWait, 24 * 60 * 60, TimeUnit.SECONDS);
    }

    if (logger.isDebugEnabled()) logger.debug("Update checker [REGISTERED]");
  }