Kivy MD how to use multiple ScreenManagers

[Christoph Bauer]

For the purpose of having multiple Screens for App startup (without BottomAppBar) and later after sucessful login having multiple Screens with BottomAppBar I tried to solve this by initializing two ScreenManagers in the *.kv File.

See below the structure of the *.kv file.

Question: How can I handle the ScreenManagers ('sm' and 'ssm') from the *.py File?

Current status:  'sm' appears and works as usual

Target status: 'ssm' should appear at start up; after sucessful login sm should appear

Thank you for any help!

MDScreen:

BoxLayout:

orientation:'vertical'

ScreenManager:

id:ssm

LoginScreen:

SignupScreen:

MDNavigationLayout:

x: toolbar.height

size_hint_y: 1

#size_hint_y: 1.0 - toolbar.height/root.height

ScreenManager:

id: sm

#LoginScreen:

#SignupScreen:

GraphScreen:

ActionScreen:

Screen:

name: "scr5"

MDLabel:

text: "Screen 5"

halign: "center"

MDNavigationDrawer:

id: nav_drawer

ContentNavigationDrawer:

screen_manager: sm

nav_drawer: nav_drawer

MDTopAppBar:

id: toolbar

type:"top"

title: ""

left_action_items: [["menu", lambda x: nav_drawer.set_state("open")]]

MDIconButton:

icon:"images/final_me.png"

pos_hint: {'center_x': .8,'center_y': .05}

icon_size: "60sp"