Returns the target dimensions and calculates them if necessary.
        The target dimensions are display independent.
        :return: Target dimensions as a tuple (width, height)
        :rtype: (int, int)

def get_target_dimensions(self):
        """
        Returns the target dimensions and calculates them if necessary.
        The target dimensions are display independent.
        :return: Target dimensions as a tuple (width, height)
        :rtype: (int, int)
        """
        if self.target_height is None:
            self._calculate_target_dimensions()
        return int(self.target_width), int(self.target_height)