Is there any potential risk when getting children of QObject?

[nifei]

For example, is there any potential risk in the following code?

// when re-implement QCalendarWidget's functions
QObjectList children_of_this = this->children();
  //this points to QCalendarWidget
    for( int i = 0; i < children_of_this.count(); i++)
    {
        if(children_of_this.at(i)->objectName() == "qt_calendar_navigationbar")
           {
            navigator = qobject_cast<QWidget*>(children_of_this[i]);
            if(navigator)
             {
               // do something to navigator's layout
              }
             //navigator is a pointer to a QWidget, which is previous NULL
        if(children_of_this.at(i)->objectName() == "qt_calendar_calendarview")
             {
            view = qobject_cast<QTableView*>(children_of_this[i]);
            if(view)
                      {
                      view->setItemDelegate(new QStyledItemDelegate);
                       }
              }
             //view is a pointer to a QTableView which is previous NULL
    }

// when re-implement QCalendarWidget's functions
QObjectList children_of_this = this->children();
  //this points to QCalendarWidget
    for( int i = 0; i < children_of_this.count(); i++)
    {
        if(children_of_this.at(i)->objectName() == "qt_calendar_navigationbar")
           {
            navigator = qobject_cast<QWidget*>(children_of_this[i]);
            if(navigator)
             {
               // do something to navigator's layout
              }
             //navigator is a pointer to a QWidget, which is previous NULL
        if(children_of_this.at(i)->objectName() == "qt_calendar_calendarview")
             {
            view = qobject_cast<QTableView*>(children_of_this[i]);
            if(view)
                      {
                      view->setItemDelegate(new QStyledItemDelegate);
                       }
              }
             //view is a pointer to a QTableView which is previous NULL
    }

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and in the "qcalendarwidget.cpp", the Qt's source code:

//i want to access objects like this
    d->m_view->setObjectName(QLatin1String("qt_calendar_calendarview"));
 
    navBarBackground = new QWidget(widget);
    navBarBackground->setObjectName(QLatin1String("qt_calendar_navigationbar"));

//i want to access objects like this
    d->m_view->setObjectName(QLatin1String("qt_calendar_calendarview"));
    
    navBarBackground = new QWidget(widget);
    navBarBackground->setObjectName(QLatin1String("qt_calendar_navigationbar"));

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I'm quite new to both Qt and C++ and wondering whether or not it is right to get the objects pointers those are not exposed to users.

[talk2amulya]

well, there seems nothing wrong with it...make sure "this" and "widget" are pointing to the same object

[nifei]

well, there seems nothing wrong with it...make sure "this" and "widget" are pointing to the same object

Of course they point to the same object. However, I don't think these objects are supposed to be accessed by users, are they?

[talk2amulya]

i dont understand what u mean by whether it should be accessible to the user. All you are doing is providing a navigator and view using the parent. I dont think there is any "risk" in that, although i dont totally understand ur context

[jpn]

However, I don't think these objects are supposed to be accessed by users, are they?

You're right in the sense that nobody guarantees that for example "qt_calendar_navigationbar" exists in the future. You're on your own when you rely on internal parts of Qt.