text: #!/usr/bin/env python
  """
  A simple example of a a text area displaying "Hello World!".
  """
  from __future__ import unicode_literals
  from prompt_toolkit.application import Application
  from prompt_toolkit.eventloop import use_asyncio_event_loop
  from prompt_toolkit.key_binding import KeyBindings
  from prompt_toolkit.layout import Layout
  from prompt_toolkit.widgets import Box, Frame, TextArea
  import asyncio
  
  # Layout for displaying hello world.
  # (The frame creates the border, the box takes care of the margin/padding.)
  root_container = Box(
      Frame(TextArea(
          text='Hello world!\nPress control-c to quit.',
          width=40,
          height=10,
      )),
  )
  layout = Layout(container=root_container)
  
  
  # Key bindings.
  kb = KeyBindings()
  
  @kb.add('c-c')
  def _(event):
      " Quit when control-c is pressed. "
      event.app.exit()
  
  
  # Build a main application object.
  application = Application(
      layout=layout,
      key_bindings=kb,
      full_screen=True)
  
  
  def main():
      # Tell prompt_toolkit to use asyncio.
      use_asyncio_event_loop()
  
      # Run application async.
      asyncio.get_event_loop().run_until_complete(
          application.run_async().to_asyncio_future())
  
  
  if __name__ == '__main__':
      main()
  