def mousePressEvent(self, event):
    pos = event.pos()
    self._x_start_screen = pos.x()
    self._y_start_screen = pos.y()
    self._relative_origin_x = self.wx_current
    self._relative_origin_y = self.wy_current
def mousePressEvent(self, event):
    pos = event.pos()
    self._x_start_screen = pos.x()
    self._y_start_screen = pos.y()
    self._relative_origin_x = self.wx_current
    self._relative_origin_y = self.wy_current