/**
   * Process list of event objects. Checks whether message source contact already exist for this
   * event object, if yes just update it with the new values (not sure whether we should do this, as
   * it may bring old messages) and if status of provider is changed, init its details, updates its
   * capabilities. It still adds the found messages source contact to the list of the new contacts,
   * as later we will detect this and fire update event. If nothing found a new contact is created.
   *
   * @param res list of event
   * @param cachedRecentMessages list of newly created source contacts or already existed but
   *     updated with corresponding event object
   * @param isStatusChanged whether provider status changed and we are processing
   */
  private void processEventObjects(
      Collection<EventObject> res,
      List<ComparableEvtObj> cachedRecentMessages,
      boolean isStatusChanged) {
    for (EventObject obj : res) {
      ComparableEvtObj oldMsg = findRecentMessage(obj, recentMessages);

      if (oldMsg != null) {
        oldMsg.update(obj); // update

        if (isStatusChanged && recentQuery != null) recentQuery.updateCapabilities(oldMsg, obj);

        // we still add it to cachedRecentMessages
        // later we will find it is duplicate and will fire
        // update event
        if (!cachedRecentMessages.contains(oldMsg)) cachedRecentMessages.add(oldMsg);

        continue;
      }

      oldMsg = findRecentMessage(obj, cachedRecentMessages);

      if (oldMsg == null) {
        oldMsg = new ComparableEvtObj(obj);

        if (isStatusChanged && recentQuery != null) recentQuery.updateCapabilities(oldMsg, obj);

        cachedRecentMessages.add(oldMsg);
      }
    }
  }
  /**
   * Handles new events.
   *
   * @param obj the event object
   * @param provider the provider
   * @param id the id of the source of the event
   */
  private void handle(EventObject obj, ProtocolProviderService provider, String id) {
    // check if provider - contact exist update message content
    synchronized (recentMessages) {
      ComparableEvtObj existingMsc = null;
      for (ComparableEvtObj msc : recentMessages) {
        if (msc.getProtocolProviderService().equals(provider)
            && msc.getContactAddress().equals(id)) {
          // update
          msc.update(obj);
          updateRecentMessageToHistory(msc);

          existingMsc = msc;
        }
      }

      if (existingMsc != null) {
        Collections.sort(recentMessages);
        oldestRecentMessage = recentMessages.get(recentMessages.size() - 1).getTimestamp();

        if (recentQuery != null) {
          recentQuery.updateContact(existingMsc, existingMsc.getEventObject());
          recentQuery.fireContactChanged(existingMsc);
        }

        return;
      }

      // if missing create source contact
      // and update recent messages, trim and sort
      MessageSourceContact newSourceContact =
          new MessageSourceContact(obj, MessageSourceService.this);
      newSourceContact.initDetails(obj);
      // we have already checked for duplicate
      ComparableEvtObj newMsg = new ComparableEvtObj(obj);
      recentMessages.add(newMsg);

      Collections.sort(recentMessages);
      oldestRecentMessage = recentMessages.get(recentMessages.size() - 1).getTimestamp();

      // trim
      List<ComparableEvtObj> removedItems = null;
      if (recentMessages.size() > numberOfMessages) {
        removedItems =
            new ArrayList<ComparableEvtObj>(
                recentMessages.subList(numberOfMessages, recentMessages.size()));

        recentMessages.removeAll(removedItems);
      }

      // save
      saveRecentMessageToHistory(newMsg);

      // no query nothing to fire
      if (recentQuery == null) return;

      // now fire
      if (removedItems != null) {
        for (ComparableEvtObj msc : removedItems) {
          recentQuery.fireContactRemoved(msc);
        }
      }

      recentQuery.addQueryResult(newSourceContact);
    }
  }