Method RefreshScrollbar

src/vehicle_gui.cpp:883–901

* Refresh scrollbar after selection changed */

	 * Refresh scrollbar after selection changed
	 */
	void RefreshScrollbar()
	{
		size_t scroll_row = 0;
		size_t rows = 0;
		CargoType cargo = this->selected_refit == nullptr ? INVALID_CARGO : this->selected_refit->cargo;

		for (const auto &pair : this->refit_list) {
			if (pair.first == cargo) {
				/* selected_refit points to an element in the vector so no need to search for it. */
				scroll_row = rows + (this->selected_refit - pair.second.data());
				rows += pair.second.size();
			} else {
				rows++; /* Unselected cargo type is collapsed into one row. */
			}
		}

		this->vscroll->SetCount(rows);
		this->vscroll->ScrollTowards(static_cast<int>(scroll_row));
	}

	/**
	 * Select a row.