from matplotlib import patheffects
from matplotlib.backend_bases import FigureCanvasBase, GraphicsContextBase, RendererBase
from matplotlib.figure import Figure
from matplotlib.path import Path
from matplotlib.transforms import Transform
from matplotlib.typing import ColorType


class Renderer(RendererBase):
    def __init__(self) -> None:
        super().__init__()
        self.indent = ''

    def open_group(self, s: str, gid: str | None = None) -> None:
        print(self.indent + 'open ' + s)
        self.indent += '  '
        return super().open_group(s, gid)

    def close_group(self, s: str) -> None:
        self.indent = self.indent[:-2]
        print(self.indent + 'close ' + s)
        return super().close_group(s)

    def draw_path(
        self, gc: GraphicsContextBase, path: Path, transform: Transform, rgbFace: ColorType | None = None
    ) -> None:
        pass


class Canvas(FigureCanvasBase):
    def draw(self):
        self.figure.draw(Renderer())


figure = Figure()
canvas = Canvas(figure)
ax = figure.gca()
ax.set_axis_off()

cg1 = ax.contour([[0, 1], [2, 3]])
cg1.set(path_effects=[patheffects.withTickedStroke(angle=135)])

canvas.draw()