struct DropdownWindow : Window {

	int parent_button;            ///< Parent widget number where the window is dropped from.

	const DropDownList list;      ///< List with dropdown menu items.

	byte click_delay;             ///< Timer to delay selection.

	bool drag_mode;

	bool instant_close;           ///< Close the window when the mouse button is raised.

	 * Create a dropdown menu.

	 * @param parent        Parent window.

	 * @param list          Dropdown item list.

	 * @param button        Widget of the parent window doing the dropdown.

	 * @param instant_close Close the window when the mouse button is raised.

	 * @param position      Topleft position of the dropdown menu window.

		this->parent           = parent;

		this->parent_button    = button;

		this->click_delay      = 0;

		this->drag_mode        = true;

		this->instant_close    = instant_close;

		Point pt = _cursor.pos;

		pt.x -= this->parent->left;

		pt.y -= this->parent->top;

		/* Set flag on parent widget to indicate that we have just closed. */

		NWidgetCore *nwc = this->parent->GetWidget<NWidgetCore>(this->parent_button);

			if (y + item_height - 1 <= ir.bottom) {

				Rect full{ir.left, y, ir.right, y + item_height - 1};

				if (selected) GfxFillRect(full, PC_BLACK);

				item->Draw(full, full.Shrink(WidgetDimensions::scaled.dropdowntext, RectPadding::zero), selected, colour);

		int item;

		if (this->GetDropDownItem(item)) {

			this->click_delay = 4;

			this->SetDirty();

		}

	}

			/* Close the dropdown, so it doesn't affect new window placement.

			 * Also mark it dirty in case the callback deals with the screen. (e.g. screenshots). */

			this->Close();

			return;

		}

				if (!this->GetDropDownItem(item)) return;

			}

				this->SetDirty();

			}

		}