Add a notify loading popup.

[Fran6nd]

Hello Sir!

A little contribution...

I made these changes for this project:

• osc-tui
  

The idea was that we have some requests taking a few seconds...
To prevent the app from freezing, I managed to add a notify_loading() function
wich can display an animation until the function given as parameter has finished.



I thing this might be useful for other people doing requests from npyscreen apps. br>


Here is a basic example:

#!/usr/bin/env python
# encoding: utf-8

import npyscreen
import time
class TestApp(npyscreen.NPSApp):
    def main(self):
        F  = npyscreen.Form()
        btn= F.add(npyscreen.ButtonPress)
        def test():
            def cb():
                time.sleep(5)
                return "gogo"
            res = npyscreen.utilNotify.notify_loading(cb)
            npyscreen.notify_confirm(res)
        btn.whenPressed = test
        # This lets the user interact with the Form.
        F.edit()

if __name__ == "__main__":
    App = TestApp()
    App.run()```