Why is preferred size ignored in QMainWindow (Qt5)?

idlefrog

I created a simple default project from QtCreator (without a form).
Then I change just QMainWindow. I set the size policy to minimum (vertical & horizonal).
Then I added a QLineEdit to the window, and set its vertical policy to minimum.
So the question is, why does the code below show a window that's taller than the edit bar?
![alt text](image url)

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    QSizePolicy policy = QSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);
    setSizePolicy(policy);

    QWidget     *widget = new QWidget();
    QVBoxLayout *layout = new QVBoxLayout();
    QLineEdit   *edit   = new QLineEdit;

    policy = QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
    edit->setSizePolicy(policy);
    edit->setGeometry(0,0, 96,56);

    layout->addWidget(edit);
    widget->setLayout(layout);

    setCentralWidget(widget);
}

What am I missing? Why doesn't it look like this below ? :

Of course, if I used QWidget instead of QMainWindow, it would look fine, but what do I need to set in QMainWindow for it not to pad out space vertically around the label?
Alternatively, I just add the call resize(sizeHint()); inside QMainWindow's constructor (at the end)?
This works, but it seems a bit clumsy.

Mitsuriou

Hello,

I'm not sure these are the best practises but please try to:

Remove the calls related to the size policy. The window will be taking the less needed space, by default, If I'm not mistaken.
And, or, remove the explicit call to setGeometry() to let default values being applied;
And, or, call adjustSize() just before calling show().