add: CHECK_CLASS(tPtr, WC_TextField);
context: WMSetTextFieldFont(WMTextField *tPtr, WMFont *font){    if (tPtr->font)	WMReleaseFont(tPtr->font);    tPtr->font = WMRetainFont(font);      tPtr->offsetWidth = 	WMAX((tPtr->view->size.height - WMFontHeight(tPtr->font))/2, 1);    if (tPtr->view->flags.realized) {	paintTextField(tPtr);    }}