- 
    Bug 
- 
    Resolution: Unresolved
- 
    P2: Important 
- 
    None
- 
    6.4.0
- 
    None
- 
    Windows 10, x64, Visual Studio 2022
If you put a QOpenGLWidget in a QMdiSubWindow and you add the sub window in a QMdiArea that is the central widget of a QMainWindow, the main window disappears for a moment, then it reappears in a different position.
A sample code to reproduce the issue:
QMainWindow* mw = new QMainWindow(); QMdiArea* mdi = new QMdiArea(mw); mw->setCentralWidget(mdi); QToolBar* toolbar = mw->addToolBar(QString("Main toolbar")); QAction* testAction = toolbar->addAction(QString("Test")); connect(testAction, &QAction::triggered, [=]() { QOpenGLWidget* oglw = new QOpenGLWidget(); QMdiSubWindow* sw = new QMdiSubWindow(); sw->setWidget(oglw); mdi->addSubWindow(sw); sw->show(); }); mw->show();
(click on the "Test" action to add the sub window)
The problem only occurs the first time you add the sub window.
- is duplicated by
- 
                    QTBUG-107590 MainWindow flash off/on -           
- Closed
 
-         
- 
                    QTBUG-109462 Inserting a QOpenGLWidget causes a recreation of the top level window -           
- Closed
 
-         
- 
                    QTBUG-109424 QWebEngineView can cause window to briefly disappear and change position -         
- Closed
 
-         
| For Gerrit Dashboard: QTBUG-107585 | ||||||
|---|---|---|---|---|---|---|
| # | Subject | Branch | Project | Status | CR | V | 
| 449339,6 | WIP: Reduce window recreations with dynamically added OpenGL-based widgets | dev | qt/qtbase | Status: NEW | -2 | 0 |