#!/usr/bin/env python3

from kivy.app import App
from kivy.uix.dropdown import DropDown
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.popup import Popup
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.textinput import TextInput


sm = ScreenManager()


class MainScreen(Screen):
    name = 'foo'
    l = Button()

class MainWindow(BoxLayout):
    def on_enter(self, *args):
        pass


class MyApp(App):
    def build(self):
        sm.add_widget(MainScreen)
        return(MainWindow())


if __name__ == '__main__':
    MyApp().run()