: FloatLayout: MDTopAppBar: pos_hint: {"top": 1} left_action_items: [['chevron-left', lambda x: root.go_back()]] RoundedCard: pos_hint: {"center_y": .5, "center_x": .5} orientation: "vertical" size_hint: 0.5, 0.5 md_bg_color: self.theme_cls.primary_color padding: "10sp" RoundedCard: orientation: "vertical" size_hint_y: 2 padding: "20sp" DetailBox: id: email size_hint_x: .9 pos_hint: {"center_x": .5, "top": .7} hint_text: "Email" DetailBox: id: password size_hint_x: .9 pos_hint: {"center_x": .5, "top": .575} hint_text: "Password" password: True disabled: True if not email.text else False MDBoxLayout: orientation: "horizontal" spacing: "5sp" Widget: size_hint_y: 3 MyButton: id: sign_in_button text: "Sign in" disabled: True if not email.text else False md_bg_color: app.theme_cls.primary_light theme_text_color: "Custom" text_color: app.get_text_color(self.theme_cls.primary_light_hue) on_press: root.parent.current = "sign_in_screen" root.parent.parent.ids.sign_in_screen.ids.email.text = email.text root.parent.parent.ids.sign_in_screen.ids.password.text = password.text MyButton: text: "Create Account" disabled: True if not email.text else False on_press: # Need to refer to the FirebaseLoginScreen root.parent.parent.sign_up(email.text, password.text) sign_in_button.disabled = True root.parent.parent.display_loading_screen() root.parent.parent.ids.sign_in_screen.ids.email.text = email.text root.parent.parent.ids.sign_in_screen.ids.password.text = password.text