Maximize and minimize buttons in an undocked QDockWidget

Question

I´ve been trying to add the buttons to an undocked QDockWidget window as I normally do for a QDialog, but with no success as follows:

QDockWidget* dw = new QDockWidget(QString("Stream %1").arg(i + 1), this); 
dw->setWindowFlags((dw->windowFlags() | Qt::WindowMaximizeButtonHint |
    Qt::WindowMinimizeButtonHint | Qt::WindowCloseButtonHint));

When I undock them they still only have the [X] close button.

What am I missing?

Development environment info: Windows 10 x64, Visual Studio 2015, Qt 5.7.1, C++

Answer 1

I figured out how to do it. You have to connect to the QDockWidget toplevelChanged(bool) signal.

connect(ui.dockWidget, SIGNAL(topLevelChanged(bool)), this, SLOT(dockWidget_topLevelChanged(bool)));

Then you need to check if its floating and set the window hints.

void MyClass::dockWidget_topLevelChanged(bool)
{
    QDockWidget* dw = static_cast<QDockWidget*>(QObject::sender());
    if (dw->isFloating())
    {
        dw->setWindowFlags(Qt::CustomizeWindowHint |
            Qt::Window | Qt::WindowMinimizeButtonHint |
            Qt::WindowMaximizeButtonHint |
            Qt::WindowCloseButtonHint);
        dw->show();
    }
}