The QBoxLayout class lines up child widgets horizontally or vertically. ... QBoxLayout  ( QWidget * parent, Direction, int border=0, int autoBorder = -1, const char * name=0 )  . ... QBoxLayout takes the space it gets (from its parent layout or from the mainWindget()), divides it up into a row of boxes and makes each managed widget fill one box. ... The stretch factor applies only in the direction of the QBoxLayout, and is relative to the other boxes and widgets in this QBoxLayout. ...