Kivy: orientation change

orientation.kv

FloatLayout:
    screen_orientation: 'landscape' if self.width > self.height else 'portrait'

    BoxLayout:
        orientation: 'vertical'
        disabled: root.screen_orientation != 'portrait'
        size_hint: (None, None) if self.disabled else (1, 1)
        size: (0, 0) if self.disabled else (100, 100)
        opacity: 0 if self.disabled else 1

        Button
        Button
        Button

    BoxLayout:
        orientation: 'horizontal'
        disabled: root.screen_orientation != 'landscape'
        size_hint: (None, None) if self.disabled else (1, 1)
        size: (0, 0) if self.disabled else (100, 100)
        opacity: 0 if self.disabled else 1

        Button
        Button
        Button