code: def clicked(self, event):
          
          group = event.artist._mt_group
          indices = event.ind
  
          # double click only supported on 1.2 or later
          major, minor, _ = mpl_version.split('.')
          if (int(major), int(minor)) < (1, 2) or not event.mouseevent.dblclick:
              for i in indices:
                  print(self.groups[group][i].line_str)
  
          else:
              # toggle durline
              first = indices[0]
              logevent = self.groups[group][first]
  
              try:
                  # remove triangle for this event
                  idx = map(itemgetter(0), self.durlines).index(logevent)
                  _, poly = self.durlines[idx]
                  poly.remove()
                  plt.gcf().canvas.draw()
                  del self.durlines[idx]
  
              except ValueError:
                  # construct triangle and add to list of durlines
  
                  if self.args['optime_start']:
                      pts = [[date2num(logevent.datetime), 0],
                             [date2num(logevent.datetime), logevent.duration],
                             [date2num(logevent.datetime +
                                       timedelta(milliseconds=logevent.duration)
                                       ), 0]]
                  else:
                      pts = [[date2num(logevent.datetime), 0],
                             [date2num(logevent.datetime), logevent.duration],
                             [date2num(logevent.datetime -
                                       timedelta(milliseconds=logevent.duration)
                                       ), 0]]
  
                  poly = Polygon(pts, closed=True, alpha=0.2, linewidth=0,
                                 facecolor=event.artist.get_markerfacecolor(),
                                 edgecolor=None, zorder=-10000)
  
                  ax = plt.gca()
                  ax.add_patch(poly)
                  plt.gcf().canvas.draw()
  
                  self.durlines.append((logevent, poly))
docs: Call if an element of this plottype is clicked.
  
          Implement in sub class.