code: func (v *View) SetCursor(x, y int) error {
  	maxX, maxY := v.Size()
  	if x < 0 || x >= maxX || y < 0 || y >= maxY {
  		return errors.New("invalid point")
  	}
  	v.cx = x
  	v.cy = y
  	return nil
  }
docs: // SetCursor sets the cursor position of the view at the given point,
  // relative to the view. It checks if the position is valid.