CODE EXAMPLE FOR CPP

set width qpushbutton

//Use this:

QPushButton* const button = new QPushButton(QString("<"), this); 
const QSize BUTTON_SIZE = QSize(22, 22);
button->setMinimumSize(BUTTON_SIZE);

//or:

button->setSize(BUTTON_SIZE);

//or:

button->setMinimumSize(BUTTON_SIZE);