def height(self):
        """height in pixels"""
        alloc_h = self.alloc_h

        if self.parent and isinstance(self.parent, graphics.Scene):
            alloc_h = self.parent.height

        min_height = (self.min_height or 0) + self.margin_top + self.margin_bottom
        h = alloc_h if alloc_h is not None and self.fill else min_height
        h = max(h or 0, self.get_min_size()[1])
        return h - self.margin_top - self.margin_bottom
height in pixels