Text box for manim

manim_textbox.py

def create_textbox(string, width, height, text_color=BLACK, align=ORIGIN, color=BLUE, buff=0.2):
    tex_align = {
        tuple(UL): "\\raggedright",
        tuple(LEFT): "\\raggedright",
        tuple(DL): "\\raggedright",
        tuple(UP): "\\centering",
        tuple(ORIGIN): "\\centering",
        tuple(DOWN): "\\centering",
        tuple(UR): "\\raggedleft",
        tuple(RIGHT): "\\raggedleft",
        tuple(DR): "\\raggedleft",
    }
    text_width = width - 2*buff
    box = Rectangle(width=width, height=height, fill_color=color, fill_opacity=0.8, stroke_color=color, stroke_opacity=1)
    text_tex = f"{tex_align[tuple(align)]} {string}"  
    text = Tex(text_tex, 
               tex_environment=f"{{minipage}}{{{text_width*0.7}cm}}", color=text_color)
    if text.height > height-2*buff:
        new_scale = (height-2*buff)/text.height
        new_text_width = text_width/new_scale
        text = Tex(text_tex, tex_environment=f"{{minipage}}{{{new_text_width*0.7}cm}}", color=text_color)
        text.scale(new_scale)
    result = VGroup() # create a VGroup
    result.add(box, text.next_to(box.get_corner(align), -align, buff=buff)) # add both objects to the VGroup
    return text, result


# Demo
class Test(Scene):
    def construct(self):
        for msg, align in [("Centered text", ORIGIN),
                           ("Left-aligned text", LEFT), 
                           ("Right-aligned text", RIGHT),
                           ("Top-aligned text", UP),
                           ("Bottom-aligned text", DOWN),
                           ("Top-left-aligned text", UL),
                           ("Top-right-aligned text", UR),
                           ("Bottom-left-aligned text", DL),
                           ("Bottom-right-aligned text", DR)
                           ]:
            extra_msg = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed non risus. Suspendisse lectus tortor, dignissim sit amet, adipiscing nec, ultricies sed, dolor."
            text, box = create_textbox(f"{msg} {extra_msg}", 
                                       width=10, height=5, text_color=BLACK, align=align)
            self.add(box)
            self.wait()
            self.play(FadeOut(box))