CloseEvent does not close a hidden main window

Question

I have a QMainWindow that minimizes to the tray. In the tray I have two right mouse click menus. Show/Hide and Exit.

When the window is visible and I click to exit menu, the application closes correctly.

When the windows is not visible (hide), the application remains open.

The problem is not in the MainWindow::CloseEvent(). According to information from the debugger - the application correctly enters the closeEvent function, but it won't end.

Am I doing something wrong, is this a feature or a bug? I tried putting this->show() first before exiting, but it had no effect on the result.

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{

    ...

    /* try icon */
    trayIcon = new QSystemTrayIcon(this);
    trayIcon->setIcon(this->style()->standardIcon(QStyle::SP_ComputerIcon));
    trayIcon->setToolTip("Tray Program.\nWorking with minimizing the tray program.");
    menu = new QMenu(this);
    viewWindow = new QAction(("Maximize window"), this);
    quitAction = new QAction(("Exit"), this);
    connect(viewWindow, SIGNAL(triggered()), this, SLOT(show()));
    connect(quitAction, SIGNAL(triggered()), this, SLOT(closeFromTray()));
    closedFromTray = false;

    menu->addAction(viewWindow);
    menu->addAction(quitAction);

    trayIcon->setContextMenu(menu);
    trayIcon->show();

    connect(trayIcon, SIGNAL(activated(QSystemTrayIcon::ActivationReason)), this, SLOT(iconActivated(QSystemTrayIcon::ActivationReason)));

    ...
}
    
void MainWindow::closeEvent(QCloseEvent * event)
{
    if(!closedFromTray)
    {
        this->hide();
        event->ignore();
    }
    else
    {
        event->accept();
    }
    QMainWindow::closeEvent(event);
}

void MainWindow::iconActivated(QSystemTrayIcon::ActivationReason reason)
{
    switch (reason)
    {
        case QSystemTrayIcon::Trigger:
            if(!this->isVisible())
            {
                this->show();
            }
            else 
            {
                this->hide();
            }
            break;
        default:
            break;
    }
}
    
void MainWindow::closeFromTray()
{
    closedFromTray = true;
    close();
}

• Qt creator 11.0.2.
• Qt 6.5.2 with all latest updates.

How to terminate the application even when the window is hidden?

Answer 1

From QGuiApplication::quitOnLastWindowClosed with my emphasis:

If this property is true, the applications quits when the last visible primary window (i.e. top level window with no transient parent) is closed.". .

Use qApp->quit(); instead of close();.