def change_event_type(self):
        """Action: change highlighted event's type by cycling through event 
        type list."""
        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)
Action: change highlighted event's type by cycling through event 
        type list.