code: def exec_(self):
          
          # create the tray icon
          if self.autoCreateTrayIcon() and not self.trayIcon():
              try:
                  window = self.topLevelWindows()[0]
              except IndexError:
                  pass
              else:
                  # create the menu
                  menu = QtGui.QMenu(window)
                  
                  if self.applicationName():
                      act = menu.addAction('Quit {0}'.format(self.applicationName()))
                  else:
                      act = menu.addAction('Quit')
                  
                  act.triggered.connect(self.quit)
                  
                  # create the tray icon
                  icon = QtGui.QSystemTrayIcon()
                  icon.setIcon(self.windowIcon())
                  icon.setObjectName('trayIcon')
                  icon.setContextMenu(menu)
                  icon.setToolTip(self.applicationName())
                  icon.show()
                  
                  self._trayIcon = icon
          
          result = super(XApplication, self).exec_()
          
          # save the settings before exiting
          self.saveSettings()
          return result
docs: Runs the main application for this instance and returns the
          success value.
          
          :return     <int>