/**
   * Initializes custom contact action buttons.
   *
   * @param contactActionButtons the list of buttons to initialize
   * @param gridX the X grid of the first button
   * @param xBounds the x bounds of the first button
   * @return the new grid X coordinate after adding all the buttons
   */
  private int initGroupActionButtons(
      Collection<SIPCommButton> contactActionButtons, int gridX, int xBounds) {
    // Reinit the labels to take the whole horizontal space.
    addLabels(gridX + contactActionButtons.size());

    Iterator<SIPCommButton> actionsIter = contactActionButtons.iterator();
    while (actionsIter.hasNext()) {
      final SIPCommButton actionButton = actionsIter.next();

      // We need to explicitly remove the buttons from the tooltip manager,
      // because we're going to manager the tooltip ourselves in the
      // DefaultTreeContactList class. We need to do this in order to have
      // a different tooltip for every button and for non button area.
      ToolTipManager.sharedInstance().unregisterComponent(actionButton);

      if (customActionButtonsUIGroup == null)
        customActionButtonsUIGroup = new LinkedList<JButton>();

      customActionButtonsUIGroup.add(actionButton);

      xBounds += addButton(actionButton, ++gridX, xBounds, false);
    }

    return gridX;
  }
  /** Inializes button tool tips. */
  private void initButtonToolTips() {
    callButton.setToolTipText(
        GuiActivator.getResources().getI18NString("service.gui.CALL_CONTACT"));
    callVideoButton.setToolTipText(
        GuiActivator.getResources().getI18NString("service.gui.VIDEO_CALL"));
    desktopSharingButton.setToolTipText(
        GuiActivator.getResources().getI18NString("service.gui.SHARE_DESKTOP"));
    chatButton.setToolTipText(
        GuiActivator.getResources().getI18NString("service.gui.SEND_MESSAGE"));
    addContactButton.setToolTipText(
        GuiActivator.getResources().getI18NString("service.gui.ADD_CONTACT"));

    // We need to explicitly remove the buttons from the tooltip manager,
    // because we're going to manager the tooltip ourselves in the
    // DefaultTreeContactList class. We need to do this in order to have
    // a different tooltip for every button and for non button area.
    ToolTipManager ttManager = ToolTipManager.sharedInstance();
    ttManager.unregisterComponent(callButton);
    ttManager.unregisterComponent(callVideoButton);
    ttManager.unregisterComponent(desktopSharingButton);
    ttManager.unregisterComponent(chatButton);
    ttManager.unregisterComponent(addContactButton);
  }