zbarcam.kv

#:import XCamera kivy.garden.xcamera.XCamera
<ZBarCam>:
    Widget:
        # invert width/height on rotated Android
        # https://stackoverflow.com/a/45192295/185510
        id: proxy
        XCamera:
            id: xcamera
            play: True
            resolution: root.resolution
            allow_stretch: True
            keep_ratio: True
            center: self.size and proxy.center
            size:
                (proxy.height, proxy.width) if root.is_android() \
                else (proxy.width, proxy.height)
            # Android camera rotation workaround, refs:
            # https://github.com/AndreMiras/garden.zbarcam/issues/3
            canvas.before:
                PushMatrix
                Rotate:
                    angle: -90 if root.is_android() else 0
                    origin: self.center
            canvas.after:
                PopMatrix