main.kv

<BorderImage>
    canvas.after:
        Color:
            rgba: (0, 0, 0, 0.5) if root.border_ else (0, 0, 0, 0)
        Line:
            width: 1.2
            rectangle: (self.x, self.y, self.width, self.height)

        Color:
            rgba: (1, 1, 1, 0.5) if root.border_ else (0, 0, 0, 0)
        Line:
            width: 1.2
            rectangle: (self.x - 2.4, self.y - 2.4, self.width + 4.8, self.height + 4.8)


TouchableScreen:
    ScreenManager:
        id: scr_manager

        Screen:
            name: 'home'
            on_enter:
                app.mouse.set_cursor_icon('transparent.png')
                app.show_cursor(True)

            MDBoxLayout:
                orientation: 'vertical'
                padding: dp(10)
                spacing: dp(50)
                adaptive_size: True
                pos_hint: {'center_x': 0.5, 'center_y': 0.5}

                MDRectangleFlatButton:
                    text: 'Open demo with canvas'
                    on_release: app.change_screen('1')

                MDRectangleFlatButton:
                    text: 'Open demo with image'
                    on_release: app.change_screen('2')

        Screen:
            name: '1' # demo with canvas
            on_enter:
                app.mouse.set_cursor_icon('pipette.png')
                app.show_cursor(False)

            BoxLayout:
                id: layout_1
                padding: dp(10)
                spacing: dp(10)

                BoxLayout:
                    orientation: 'vertical'
                    spacing: dp(10)
                    padding: dp(10)

                    BoxLayout:
                        canvas.before:
                            Color:
                                rgba: (0, 0, 0, 1)
                            Rectangle:
                                size: self.size
                                pos: self.pos

                    BoxLayout:
                        canvas.before:
                            Color:
                                rgba: (1, 1, 1, 1)
                            Rectangle:
                                size: self.size
                                pos: self.pos

                    BoxLayout:
                        canvas.before:
                            Color:
                                rgba: (1, 0, 0, 1)
                            Rectangle:
                                size: self.size
                                pos: self.pos

                    BoxLayout:
                        canvas.before:
                            Color:
                                rgba: (0, 0.5, 0, 1)
                            Rectangle:
                                size: self.size
                                pos: self.pos

                BoxLayout:
                    canvas.before:
                        Color:
                            rgba: (0.5, 0, 0.5, 1)
                        Rectangle:
                            size: self.size
                            pos: self.pos

        Screen:
            name: '2'
            on_enter:
                app.mouse.set_cursor_icon('pipette.png')
                app.show_cursor(False)

            Image:
                id: layout_2
                source: 'test.jpg'