A window is drawn on the game screen at every WE_PAINT window event.

Opening a window

Creating a new struct of a window opens a new window. It should be provided with a doxygen comment explaining the function.

Example:

/**
 * Opens a new instance of a MyNew window.
 * @param void Any parameters required by window
 */
void ShowMyNewWindow(void)
{
	DeleteWindowByClass(window class);
	new MyNewWindow(void);
}

Describing a window

Set up a WindowDesc with the name you gave this->CreateNestedTree() and this->FinishInitNested().

Syntax:

/** Window description for my new window. */
static const WindowDesc _mywindow_desc(
	window positioning,
        default width,
        default height,
        window class,
        parent window class,
        window flags
        widget parts,
        lengthof(widget parts)
);

You will also need a struct describing You can find plenty of examples in the source code, look in a *_gui.cpp file.

Window positioning

The window positioning is one of the values of the WindowPosition enum defined in src/window_gui.h.

Window classes

A window class is a unique number that represents a (set of) windows, for example a window that displays a town has class WC_TOWN_VIEW. To differentiate which town is displayed by an actual window, the latter has an additional window number.

The list of available window classes is defined by the WindowClass enum, in src/window_type.h.

Setting up widgets

Syntax:

static const NWidgetPart _nested_mywindow_widgets[] = {
        NWidget(nwid),
                 NWidget(wwt, colour, wid), SetDataTip(STR_NULL, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS),
        EndContainer(),
};
</pre>

:;<nowiki>Example:</nowiki>

<pre>
static const NWidgetPart _nested_mywindow_widgets[] = {
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_TEXT, COLOUR_MAUVE), SetDataTip(STR_NEWGRF_SETTINGS_SELECT_PRESET, STR_NULL),
				SetPadding(0, WD_FRAMETEXT_RIGHT, 0, 0),
		NWidget(WWT_DROPDOWN, COLOUR_YELLOW, WID_NS_PRESET_LIST), SetFill(1, 0), SetResize(1, 0),
				SetDataTip(STR_JUST_STRING, STR_NEWGRF_SETTINGS_PRESET_LIST_TOOLTIP),
	EndContainer(),
};

Widget types

WWT_EMPTY

To Do
-Include an explanation.

WWT_PANEL

A simple depressed panel.

WWT_INSET

A depressed panel, most commonly used as a combo box text area.

WWT_IMGBTN

Image button.

WWT_IMGBTN_2

Image button. Image changes when button is pressed.

WWT_TEXTBTN

Text button.

WWT_TEXTBTN_2

Text button. Text changes when button is pressed.

WWT_LABEL

A centered label.

WWT_MATRIX

To Do
-Include an explanation.

WWT_SCROLLBAR

To Do
-Include an explanation.

WWT_FRAME

To Do
-Include an explanation.

WWT_CAPTION

To Do
-Include an explanation.

WWT_HSCROLLBAR

To Do
-Include an explanation.

WWT_STICKYBOX

The button for stickying a window.

WWT_SCROLL2BAR

To Do
-Include an explanation.

WWT_RESIZEBOX

The button for resizing a window.

WWT_CLOSEBOX

The button for closing a window.

WWT_PUSHBTN

To Do
-Include an explanation.

WWT_PUSHTXTBTN

To Do
-Include an explanation.

WWT_PUSHIMGBTN

To Do
-Include an explanation.

Colours

For a list of available colors, see Colours.

Maintaining the window

Define what to do with the window in a struct, with a constructor

Example:

struct MyNewWindow {
        MyNewWindow()
        {
        }
        ....
}