[Interest] Qml MessageDialog not centered over window

[Shawn Rutledge]

> On 25 Sep 2017, at 13:17, Murphy, Sean <smurphy at walbro.com> wrote:
> 
> And in my real main.cpp I have
>  QApplication app(argc, argv);
>  QQmlEngine engine;
>  QQmlComponent component(&engine, QUrl("qrc:/qml/dashboard.qml"));
>  component.create();
> Whereas the project that was generated by Creator when I was testing your 
> example is
>  QGuiApplication app(argc, argv);
>  QQmlApplicationEngine engine;
>  engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

Aha, it happens when using a QApplication; the MessageDialog is actually a QMessageBox in that case.  I can get the same result with the test qml like this:

qml -apptype widget messagedialog.qml

(that makes the qml runtime use a QApplication instead of QGuiApplication) and maybe we have some trouble making a QWidget dialog transient for a QWindow.  In  QMessageBoxHelper::show(), it does try to set its transient parent:

     virtual bool show(Qt::WindowFlags f, Qt::WindowModality m, QWindow *parent) {
        m_dialog.winId();
        QWindow *window = m_dialog.windowHandle();
        Q_ASSERT(window);
        window->setTransientParent(parent); 
 qDebug() << window << "transient for" << parent;
    … }

QMessageBoxHelper::show - QWidgetWindow(0x7fcf52d80a40, name="QMessageBoxClassWindow") transient for QQuickWindowQmlImpl(0x7fcf54a192c0)

I wrote it up as QTBUG-63406.