code: def apply(self):
          
          self.read_group_info()
  
          if self.tabs.count() == 0:
              # disactivate buttons
              self.button_color.setEnabled(False)
              self.button_del.setEnabled(False)
              self.button_apply.setEnabled(False)
          else:
              # activate buttons
              self.button_color.setEnabled(True)
              self.button_del.setEnabled(True)
              self.button_apply.setEnabled(True)
  
          if self.groups:
              self.parent.overview.update_position()
              self.parent.spectrum.update()
              self.parent.notes.enable_events()
          else:
              self.parent.traces.reset()
              self.parent.spectrum.reset()
              self.parent.notes.enable_events()
docs: Apply changes to the plots.