code: def on_key_press(self, event):
      if event.text == " ":
          self.index = (self.index + 1) % (len(self.markers.symbols))
          self.markers.symbol = self.markers.symbols[self.index]
          self.text.text = self.markers.symbols[self.index]
          self.update()
  
file_path: vispy/examples/basics/visuals/rescalingmarkers.py
imports: import numpy
  import vispy.scene
  from vispy.scene import visuals
  from vispy import app
label_desc: Use image node_id 2 for calling the Canvas obj's underlying member method code with example usage: obj.on_key_press(event) without return types