Kivy button press to next page - class

Question

from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
class LoginScreen(GridLayout):
def __init__(self, **kwargs):
super(LoginScreen, self).__init__(**kwargs)
self.cols = 2
self.submit = Button(text='Order', font_size=40)
self.add_widget(self.submit)
self.submit.bind(on_press=self.pressed)
def pressed(self, instance):
pressing = Secondtab()
pressing()
class Secondtab(GridLayout):
def __init__(self, **kwargs):
super(Secondtab, self).__init__(**kwargs)
self.cols = 5
self.submit = Button(text='Drinks', font_size=40)
self.add_widget(self.submit)
print('check')
def __call__(self):
print('new tab')
class MyApp(App):
def build(self):
return LoginScreen()
if __name__ == '__main__':
MyApp().run()
So I want the window to change to a new layout when I press the first button. I tought making a new grid class and calling it would work but it didnt work as I expected. I dont want the button to open a new window tho I want the current window to refresh to the new layout.

Answer 1

As #John Anderson suggested. Take a look at the screen manager widget. The 'current window' must be a populated screen widget and you could change the current screen by assigning the next screen's name to the current attribute.

Answer 2

This will help you I guess. Using ScreenManager:
from kivy.uix.screenmanager import ScreenManager, Screen, SlideTransition
class LoginScreen(GridLayout):
def __init__(self, **kwargs):
super(LoginScreen, self).__init__(**kwargs)
self.cols = 2
self.submit = Button(text='Order', font_size=40)
self.add_widget(self.submit)
self.submit.bind(on_press=self.pressed)
def pressed(self, instance):
pressing = Secondtab()
pressing()
myapp.screen_manager.transition = SlideTransition(direction='left', duration=.25) #You can change transition speed or you could just remove it to set it on default
myapp.screen_manager.current = 'Secondtab'
class MyApp(App):
def build(self):
return LoginScreen()
self.screen_manager = ScreenManager()
self.loginscreen = LoginScreen()
screen = Screen(name='LoginScreen')
screen.add_widget(self.loginscreen)
self.screen_manager.add_widget(screen)
self.secondtab = Secondtab()
screen = Screen(name='Secondtab')
screen.add_widget(self.secondtab)
self.screen_manager.add_widget(screen)
return self.screen_manager