The way users interact with edit boxes is influenced by the widget focus system. This page describes what modifications that are necessary to add a text box to a window that do not have it yet.

Checklist for adding a text box to a window

• Add a constant for the widget index eg. OP_WIDGET_NUM_PIZZAS_EDIT (OP = Order Pizza window). Follow the naming pattern of the other widgets in the same window.
• Add an edit box to the nested widget array:

NWidget(WWT_EDITBOX, COLOUR_WHITE, OP_WIDGET_NUM_PIZZAS_EDIT), 
  SetDataTip(STR_ORDER_PIZZA_NUM_PIZZAS_OSKTITLE, STR_ORDER_PIZZA_NUM_PIZZAS_TOOLTIP),

(should be on one line, but has been broken up on two lines here on the wiki to avoid horizontal scrolling)

• Add a QueryString member variable to the window class, and initialise it in the constructor with the maximum desired text length.

QueryString filter_editbox; ///< Filter editbox;

• In your constructor (after FinishInitNested resp. InitNested) link the editbox with the QueryString:

/* Initialize the text edit widget */
this->querystrings[WID_SIL_FILTER_TEXT] = &this->filter_editbox;

• If needed, assign special behaviour to ENTER/ESC keys, resp OK/CANCEL buttons in the OSK window. For filter editboxes it is expected that ESC clears the editbox:

this->filter_editbox.ok_button = WID_SIL_FILTER_ENTER_BTN;
this->filter_editbox.cancel_button = QueryString::ACTION_CLEAR;

• Via the QueryString you can set some other properties, like restricting the accepted character set to digits etc.
• If you want to focus the edit box by default when the window opens, call the SetFocusedWidget function:

this->SetFocusedWidget(OP_WIDGET_NUM_PIZZAS_EDIT);

• If you want editing the editbox trigger some functionality, override the window member function:

virtual void OnEditboxChanged(int widget)

Related articles