Method draw

官方samples/common.py:191–196

(self, vis)

                if rect:
                    self.callback(rect)
    def draw(self, vis):
        if not self.drag_rect:
            return False
        x0, y0, x1, y1 = self.drag_rect
        cv2.rectangle(vis, (x0, y0), (x1, y1), (0, 255, 0), 2)
        return True
    @property
    def dragging(self):
        return self.drag_rect is not None