Parameters to create_ok_dialog(), create_ok_cancel_dialog(), and other standard dialog creation functions include one or two callbacks that get invoked whenever the dialog gets closed. In addition to the IN_THREAD or THREAD_CALLBACK calling convention the callbacks also receive an x::w::ok_cancel_callback_args parameter that provides a possibly null() pointer reference to the dialog's parent window, and the x::w::busy mcguffin factory.

The x::w::input_dialog's callback receives a x::w::input_dialog_ok_args parameter, that inherits from x::w::ok_cancel_callback_args and has an additional dialog_input_field class member.