#include <QtWidgets>

class ToolBar : public QToolBar
{
    Q_OBJECT
  public:
    using QToolBar::QToolBar;

#ifdef Q_OS_LINUX
  protected:
    void showEvent(QShowEvent *e) override
    {
      QToolBar::showEvent(e);
      if (isFloating() && windowFlags().testFlag(Qt::X11BypassWindowManagerHint) ) {
        //  QMainWindow::show() after QMainWindow::restoreState() will break the minimizing again so we should delay calling adjustToolbar().
        QMetaObject::invokeMethod(this, "adjustToolbar", Qt::QueuedConnection);
        // If we're sure restoreState() is only called after show() then adjustToolbar() could be called here directly instead.
        //adjustToolbar();
      }
    }

  private slots:
    void adjustToolbar()
    {
      const bool vis = !isHidden();
      hide();
      setWindowFlags(windowFlags() & ~Qt::X11BypassWindowManagerHint);
      if (vis)
        show();
    }
#endif
};

class MainWindow : public QMainWindow
{
		Q_OBJECT

	public:
		MainWindow(QWidget *parent = nullptr)
		  : QMainWindow(parent)
		{
      QComboBox* cb1 = new QComboBox(this);
      cb1->setEditable(true);

			QToolBar* goodTb = new ToolBar(this);
			goodTb->setObjectName("Toolbar_1");
      goodTb->setWindowTitle("Good Toolbar");
			goodTb->addWidget(cb1);
      goodTb->addAction("Good Bar");

      QComboBox* cb2 = new QComboBox(this);
      cb2->setEditable(true);

      QToolBar* badTb = new QToolBar(this);
      badTb->setObjectName("Toolbar_2");
      badTb->setWindowTitle("Bad Toolbar");
      badTb->addWidget(cb2);
      badTb->addAction("Bad Bar");

      addToolBar(Qt::TopToolBarArea, goodTb);
      addToolBar(Qt::BottomToolBarArea, badTb);

      // Floating dock widget restore issue test -- state must be restored after show()
      //QDockWidget *dw = new QDockWidget("Test Dock", this);
      //dw->setObjectName("DockWidget");
      //dw->setWidget(new QLineEdit("Dock widget"));
      //addDockWidget(Qt::BottomDockWidgetArea, dw);

      // Adding central widget doesn't make any difference.
      //setCentralWidget(new QWidget(this));
      //centralWidget()->setLayout(new QHBoxLayout());
      //centralWidget()->layout()->addWidget(new QLineEdit("Test Editor", this));

      show();
			readSettings();
		}

		void closeEvent(QCloseEvent *event) override
    {
			QSettings settings;
			settings.setValue("windowState", saveState());
      settings.setValue("windowGeo", saveGeometry());
			QMainWindow::closeEvent(event);
		}

		void readSettings()
		{
			QSettings settings;
      restoreGeometry(settings.value("windowGeo").toByteArray());
			restoreState(settings.value("windowState").toByteArray());
		}
};

int main(int argc, char *argv[])
{
	QApplication app(argc, argv);
  QApplication::setOrganizationName("MyCompany");
  QApplication::setApplicationName("MyApp");
  QSettings::setDefaultFormat(QSettings::IniFormat);
	MainWindow w;
	return app.exec();
}