How to bring all the application windows on top?

[Maksim Malofeev]

I have a lot of independent windows in my application (for which the transientParent value is null), so any window may be overridden by another application running in the system. Is there an easy way to bring all application windows to the front when I click on any one of them?

[Maksim Malofeev]

I got the following solution

connect(qGuiApp, &QGuiApplication::focusWindowChanged, this, [this](QWindow* focusWindow) {
      if (!focusWindow) {
        return;
      }

      auto windowList = QGuiApplication::allWindows();
      windowList.removeIf([focusWindow](QWindow* w) {
        return !w->isVisible() || w->transientParent() || w == focusWindow;
      });

      // Attempt to restore windows in the order in which they were opened.
      std::sort(windowList.begin(), windowList.end(), [](QWindow* l, QWindow* r) {
        return l->property(FOCUS_TIME_PROPERTY).value<qint64>() <
               r->property(FOCUS_TIME_PROPERTY).value<qint64>();
      });

      for (auto window : windowList) {
        qDebug() << "Raise" << window->title();
        window->raise();
      }

      focusWindow->raise();
      focusWindow->setProperty(FOCUS_TIME_PROPERTY, QDateTime::currentMSecsSinceEpoch());
    });