56     for (QComboBox* cb : findChildren<QComboBox*>()) {
 
   57         cb->installEventFilter(
this);
 
   58         cb->setFocusPolicy(Qt::StrongFocus);
 
   61     for (QSpinBox* sp : findChildren<QSpinBox*>()) {
 
   62         sp->installEventFilter(
this);
 
   63         sp->setFocusPolicy(Qt::WheelFocus);
 
   66     for (QCheckBox* cb : findChildren<QCheckBox*>()) 
 
   67         cb->installEventFilter(
this);
 
   78     if ((e->type() == QEvent::Wheel)
 
   79         && (qobject_cast<QComboBox*>(o) || qobject_cast<QAbstractSpinBox*>(o)
 
   80             || qobject_cast<QCheckBox*>(o))) {
 
   85     return QWidget::eventFilter(o, e);