Method GetTooltip

src/network/network_gui.cpp:1428–1433

* Get tooptip for a given point on the line. * @param r Rect of line. * @param pt Point of interest. * @return EncodedString of tooltip, or \c std::nullopt if none. */

	 * @return EncodedString of tooltip, or \c std::nullopt if none.
	 */
	virtual std::optional<EncodedString> GetTooltip(Rect r, const Point &pt) const
	{
		ButtonCommon *button = this->GetButton(r, pt);
		if (button == nullptr) return {};
		return GetEncodedString(button->tooltip);
	}

protected:
	/**