code: def change_event_type(self):
          
          if self.current_event is None:
              return
          
          hl_params = self.highlight.params
          self.scene.removeItem(self.highlight)
  
          ev = self.current_event
          new_name = self.parent.notes.change_event_type(name=ev['name'], 
                                                         time=(ev['start'],
                                                               ev['end']), 
                                                         chan=ev['chan'])
          msg = "Event from {} to {} changed type from '{}' to '{}'".format(
                  ev['start'], ev['end'], ev['name'], new_name)
          ev['name'] = new_name
          
          self.current_event = ev
          self.current_etype = new_name
          #self.event_sel = True
          self.parent.notes.idx_eventtype.setCurrentText(new_name)
          self.parent.statusBar().showMessage(msg)
          self.display_annotations()
          self.highlight = RectMarker(*hl_params)
          self.scene.addItem(self.highlight)
docs: Action: change highlighted event's type by cycling through event 
          type list.