Sideband/sbapp/kivymd/uix/navigationrail/navigationrail.kv

<MDNavigationRailMenuButton>
    pos_hint: {"center_x": .5, "top": 1}


<MDNavigationRailFabButton>
    type: "standard"
    pos_hint: {"center_x": .5}


<MDNavigationRail>
    size_hint: None, 1
    width: "80dp"

    PanelRoot:
        id: box_buttons

        PanelItems:
            id: box_items
            orientation: "vertical"
            spacing: "12dp"
            adaptive_size: True
            pos_hint: {"center_x": .5}


<MDNavigationRailItem>
    orientation: "vertical"
    size_hint: None, None
    size: self.navigation_rail.width if self.navigation_rail else 100, "56dp"

    RelativeLayout:
        id: container
        size_hint: None, None
        size: root.size

        RippleWidget:
            id: ripple_widget
            size_hint: None, None
            size: (container.width, container.width)
            radius: container.width / 2
            scale_value_x: 0
            scale_value_y: 0
            scale_value_z: 0
            opacity: 0
            md_bg_color:
                root.navigation_rail.ripple_color_item \
                if root.navigation_rail and \
                root.navigation_rail.ripple_color_item else \
                app.theme_cls.primary_color

        MDIcon:
            id: icon
            icon: root.icon
            opposite_colors: root.opposite_colors
            font_size: "24sp"
            pos_hint: {"center_x": .5}
            badge_icon: root.badge_icon
            badge_font_size: root.badge_font_size
            badge_icon_color:
                root.badge_icon_color \
                if root.badge_icon_color else \
                (1, 1, 1, 1)
            badge_bg_color:
                root.badge_bg_color \
                if root.badge_bg_color else \
                app.theme_cls.error_color
            theme_text_color: "Custom"
            text_color:
                ( \
                root.navigation_rail.icon_color_item_normal \
                if root.navigation_rail \
                and root.navigation_rail.icon_color_item_normal else \
                app.theme_cls.text_color \
                ) \
                if not root.active else \
                ( \
                root.navigation_rail.icon_color_item_active \
                if root.navigation_rail.icon_color_item_active else \
                app.theme_cls.text_color \
                )
            y:
                container.height - \
                ( \
                (self.height + dp(4)) \
                if root.navigation_rail and \
                root.navigation_rail.type == "unselected" else \
                (self.height - dp(8)) \
                )

            canvas.before:
                Color:
                    rgba:
                        ( \
                        ( \
                        ( \
                        app.theme_cls.primary_color \
                        if not root.navigation_rail.selected_color_background else \
                        root.navigation_rail.selected_color_background \
                        ) \
                        if root._release else \
                        (0, 0, 0, 0) \
                        ) \
                        ) \
                        if root.active else \
                        (0, 0, 0, 0)
                RoundedRectangle:
                    radius:
                        [root._selected_region_width / 2,] \
                        if root.navigation_rail and \
                        root.navigation_rail.type == "unselected" else \
                        [root._selected_region_width / 4,]
                    size:
                        root._selected_region_width, \
                        root._selected_region_width \
                        if root.navigation_rail and \
                        root.navigation_rail.type == "unselected" else \
                        root._selected_region_width / 2
                    pos:
                        self.center_x - self.width - dp(4), \
                        self.center_y - root._selected_region_width / 2 \
                        if root.navigation_rail and \
                        root.navigation_rail.type == "unselected" else \
                        self.center_y - root._selected_region_width / 4

        MDLabel:
            id: label
            text: root.text
            size_hint_x: None
            text_size: None, root.height
            adaptive_height: True
            opposite_colors: root.opposite_colors
            pos_hint: {"center_x": .5}
            y: "16"
            font_style: "Body2"
            theme_text_color: "Custom"
            font_name:
                root.navigation_rail.font_name \
                if root.navigation_rail else \
                "Roboto"
            text_color:
                ( \
                root.navigation_rail.text_color_item_normal \
                if root.navigation_rail and \
                root.navigation_rail.text_color_item_normal else \
                app.theme_cls.text_color \
                ) \
                if not root.active else \
                ( \
                root.navigation_rail.text_color_item_active \
                if root.navigation_rail.text_color_item_active else \
                app.theme_cls.text_color \
                )
            opacity:
                (0 if root.navigation_rail and \
                root.navigation_rail.type == "unselected" else 1) \
                if root.navigation_rail and \
                root.navigation_rail.type != "selected" else \
                (0 if not root.active else 1)