Qt findChild returning 0 - c++

Question

I'm currently working on a nice way to use a GUI to modify object contents at run time, project uses Qt.
So I thought of passing a QLayout to the objects, to let them create their own GUI. As POC, I created this ("display" is the name of the QVBoxLayout* parameter):
QPushButton* button = new QPushButton();
button->setText("foo");
button->setObjectName("bar");
display->addWidget(button);
which works just as fine as expected. But I will need to read what the user typed into the GuI, so this is what I did next:
QPushButton *button2 = display->findChild<QPushButton *>();
if(button2)
std::cout << button2->objectName().toStdString() << std::endl;
here nothing is put out - if() statement is false!
QList<QWidget *> widgets = display->findChildren<QWidget *>();
foreach (QWidget* b, widgets) {
std::cout << b->objectName().toStdString() << std::endl;
}
similarly, the widgets list is empty.
I tried looking through the full member list at: http://doc.qt.digia.com/qt/qvboxlayout-members.html, but findChild/findChildren seems like the best fit to my needs...
SOLUTION BELOW
This is how I handle it now:
instead of passing a QVBoxLayout to the GUI creation, a QWidget should be passed, in following named "display" as above.
QVBoxLayout* layout = new QVBoxLayout();
display->setLayout(layout);
QPushButton* button = new QPushButton();
button->setText("foo");
button->setObjectName("bar");
layout->addWidget(button);
now to findChild / findChildren:
QPushButton *button2 = display->findChild<QPushButton *>("bar");
if(button2)
std::cout << button2->objectName().toStdString() << std::endl;
QList<QWidget *> widgets = display->findChildren<QWidget *>();
foreach (QWidget* b, widgets) {
std::cout << b->objectName().toStdString() << std::endl;
}
both methods work for me as expected! (Plus, now the layout can be chosen freely by the GUI creation!)

Answer 1

The parent of a QWidget must be a QWidget. QLayout is not a QWidget.
Layouts exist to move and resize the children of a QWidget. Though you may add child widgets by making calls on the layout, ultimately, their parent will be the QWidget that the layout resides on.
To illustrate:
QWidget* widget = new QWidget;
qDebug("Widget: %p", widget);
QHBoxLayout* layout = new QHBoxLayout;
qDebug("Layout: %p", layout);
QWidget* child = new QWidget;
layout->addWidget(child);
qDebug("Child's parent before setLayout: %p", child->parent());
widget->setLayout(layout);
qDebug("Child's parent after setLayout: %p", child->parent());
Output:
Widget: 0x8e1c1e0
Layout: 0x8e1c3f0
Child's parent before setLayout: 0x0
Child's parent after setLayout: 0x8e1c1e0