class_docstr: Class that creates a callable object to retrieve events in a
  blocking way.
docstr: Event handler that will be passed to the current figure to
  retrieve events.
docstr_tok: ["Event","handler","that","will","be","passed","to","the","current","figure","to","retrieve","events","."]
code: def on_event(self, event):
      """
      Event handler that will be passed to the current figure to
      retrieve events.
      """
      # Add a new event to list - using a separate function is
      # overkill for the base class, but this is consistent with
      # subclasses
      self.add_event(event)
      _log.info("Event %i", len(self.events))
  
      # This will extract info from events
      self.post_event()
  
      # Check if we have enough events already
      if len(self.events) >= self.n and self.n > 0:
          self.fig.canvas.stop_event_loop()
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  import matplotlib.lines
  import logging
label_desc: Use image node_id 2 for calling the BlockingInput obj's underlying member method code with example usage: obj.on_event(event) without return types