add: CHECK_CLASS(tPtr, WC_TextField);
context: WMSetTextFieldCursorPosition(WMTextField *tPtr, unsigned int position){    if (tPtr->flags.enabled) {        if (position > tPtr->textLen)            position = tPtr->textLen;        tPtr->cursorPosition = position;        if (tPtr->view->flags.realized) {            paintTextField(tPtr);        }    }}