Child widget enabled in an unchecked QGroupBox

Form.h

/********************************************************************************
** Form generated from reading UI file 'designerH16672.ui'
**
** Created by: Qt User Interface Compiler version 5.4.1
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/

#ifndef DESIGNERH16672_H
#define DESIGNERH16672_H

#include <QtCore/QVariant>
#include <QtWidgets/QAction>
#include <QtWidgets/QApplication>
#include <QtWidgets/QButtonGroup>
#include <QtWidgets/QCheckBox>
#include <QtWidgets/QFrame>
#include <QtWidgets/QGroupBox>
#include <QtWidgets/QHeaderView>
#include <QtWidgets/QLabel>
#include <QtWidgets/QSpacerItem>
#include <QtWidgets/QVBoxLayout>
#include <QtWidgets/QWidget>

QT_BEGIN_NAMESPACE

class Ui_Form
{
public:
    QVBoxLayout *verticalLayout_3;
    QGroupBox *groupBox;
    QVBoxLayout *verticalLayout_2;
    QLabel *childA;
    QLabel *childB;
    QFrame *childC;
    QVBoxLayout *verticalLayout;
    QLabel *grandchild;
    QCheckBox *checkBox;
    QSpacerItem *verticalSpacer;

    void setupUi(QWidget *Form)
    {
        if (Form->objectName().isEmpty())
            Form->setObjectName(QStringLiteral("Form"));
        Form->resize(312, 179);
        verticalLayout_3 = new QVBoxLayout(Form);
        verticalLayout_3->setObjectName(QStringLiteral("verticalLayout_3"));
        groupBox = new QGroupBox(Form);
        groupBox->setObjectName(QStringLiteral("groupBox"));
        groupBox->setCheckable(true);
        verticalLayout_2 = new QVBoxLayout(groupBox);
        verticalLayout_2->setObjectName(QStringLiteral("verticalLayout_2"));
        childA = new QLabel(groupBox);
        childA->setObjectName(QStringLiteral("childA"));

        verticalLayout_2->addWidget(childA);

        childB = new QLabel(groupBox);
        childB->setObjectName(QStringLiteral("childB"));

        verticalLayout_2->addWidget(childB);

        childC = new QFrame(groupBox);
        childC->setObjectName(QStringLiteral("childC"));
        childC->setFrameShape(QFrame::Box);
        childC->setFrameShadow(QFrame::Raised);
        verticalLayout = new QVBoxLayout(childC);
        verticalLayout->setObjectName(QStringLiteral("verticalLayout"));
        grandchild = new QLabel(childC);
        grandchild->setObjectName(QStringLiteral("grandchild"));

        verticalLayout->addWidget(grandchild);


        verticalLayout_2->addWidget(childC);


        verticalLayout_3->addWidget(groupBox);

        checkBox = new QCheckBox(Form);
        checkBox->setObjectName(QStringLiteral("checkBox"));

        verticalLayout_3->addWidget(checkBox);

        verticalSpacer = new QSpacerItem(20, 40, QSizePolicy::Minimum, QSizePolicy::Expanding);

        verticalLayout_3->addItem(verticalSpacer);


        retranslateUi(Form);
        QObject::connect(checkBox, SIGNAL(clicked(bool)), childA, SLOT(setEnabled(bool)));
        QObject::connect(checkBox, SIGNAL(clicked(bool)), grandchild, SLOT(setEnabled(bool)));

        QMetaObject::connectSlotsByName(Form);
    } // setupUi

    void retranslateUi(QWidget *Form)
    {
        Form->setWindowTitle(QApplication::translate("Form", "Form", 0));
        groupBox->setTitle(QApplication::translate("Form", "Group Box", 0));
        childA->setText(QApplication::translate("Form", "Child A", 0));
        childB->setText(QApplication::translate("Form", "Child B", 0));
        grandchild->setText(QApplication::translate("Form", "Grand Child", 0));
        checkBox->setText(QApplication::translate("Form", "Child A is Enabled", 0));
    } // retranslateUi

};

namespace Ui {
    class Form: public Ui_Form {};
} // namespace Ui

QT_END_NAMESPACE

#endif // DESIGNERH16672_H