import gi

gi.require_version('Gtk', '4.0')
from gi.repository import Gtk


class MyWindow(Gtk.ApplicationWindow):
    def __init__(self, **kargs):
        super().__init__(**kargs, title='Hello World')

        self.button = Gtk.Button(label='Click Here')
        self.button.connect('clicked', self.on_button_clicked)
        self.set_child(self.button)

    def on_button_clicked(self, _widget):
        print('Hello World')
        self.close()


def on_activate(app):
    # Create window
    win = MyWindow(application=app)
    win.present()


app = Gtk.Application(application_id='com.example.App')
app.connect('activate', on_activate)

app.run(None)
