draw_path.py

import numpy as np
import matplotlib.pyplot as plt
# used for drawing
# it's hacked from lasso where there's drawing
from matplotlib.path import Path
from matplotlib.widgets import LassoSelector


class DrawPath:

    def __init__(self, ax):
        self.canvas = ax.figure.canvas
        self.lasso = LassoSelector(ax, onselect=self.onselect)

    def onselect(self, verts):
        # verts is a list of tuples
        self.path = np.array( [ [i[0], i[1]] for i in verts ] )
        #self.canvas.draw_idle()

    def disconnect(self):
        self.lasso.disconnect_events()
        self.canvas.draw_idle()


if __name__ == '__main__':

    subplot_kw = dict(xlim=(0, 1), ylim=(0, 1), autoscale_on=False)
    fig, ax = plt.subplots(subplot_kw=subplot_kw)

    selector = DrawPath(ax)

    def accept(event):
        if event.key == "enter":
            print("path points:")
            print(selector.path)
            selector.disconnect()
            ax.set_title("")
            print("TODO: run clik on me")
            exit()

    fig.canvas.mpl_connect("key_press_event", accept)
    ax.set_title("Press 'Enter' to accept drawn path.")

    plt.show()