code: def mousePressEvent(self, event):
          
          if self.scene is not None:
              x_in_scene = self.mapToScene(event.pos()).x()
              window_length = self.parent.value('window_length')
              window_start = int(floor(x_in_scene / window_length) *
                                 window_length)
              if self.parent.notes.annot is not None:
                  window_start = self.parent.notes.annot.get_epoch_start(
                          window_start)
              self.update_position(window_start)
docs: Jump to window when user clicks on overview.
  
          Parameters
          ----------
          event : instance of QtCore.QEvent
              it contains the position that was clicked.