Hide the menubar when menus lose focus (if toggled off)

* Fixes #10768
* Also fix menubar toggling not working if Qt version is less than 5.15

src/gui/MainWindow.cpp

@@ -553,14 +553,12 @@ MainWindow::MainWindow()
 
     connect(osUtils, &OSUtilsBase::statusbarThemeChanged, this, &MainWindow::updateTrayIcon);
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
-    // Install event filter for empty-area drag
+    // Install event filter for empty-area drag and menubar toggle
     auto* eventFilter = new MainWindowEventFilter(this);
     m_ui->menubar->installEventFilter(eventFilter);
     m_ui->toolBar->installEventFilter(eventFilter);
     m_ui->tabWidget->tabBar()->installEventFilter(eventFilter);
     installEventFilter(eventFilter);
-#endif
 
 #ifdef Q_OS_MACOS
     setUnifiedTitleAndToolBarOnMac(true);
@@ -2113,11 +2111,25 @@ void MainWindow::initActionCollection()
     QTimer::singleShot(1, ac, &ActionCollection::restoreShortcuts);
 }
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
-
 MainWindowEventFilter::MainWindowEventFilter(QObject* parent)
     : QObject(parent)
 {
+    m_menubarTimer.setInterval(1000);
+    m_menubarTimer.setSingleShot(false);
+    connect(&m_menubarTimer, &QTimer::timeout, this, [this] {
+        if (!config()->get(Config::GUI_HideMenubar).toBool()) {
+            // Early out reset if the menubar is toggled on
+            m_menubarTimer.stop();
+            return;
+        }
+
+        auto mainwindow = getMainWindow();
+        if (mainwindow && mainwindow->m_ui->menubar->isVisible() && !mainwindow->m_ui->menubar->activeAction()) {
+            // The menu bar is visible with no active menu, hide it
+            mainwindow->m_ui->menubar->setVisible(false);
+            m_menubarTimer.stop();
+        }
+    });
 }
 
 /**
@@ -2133,6 +2145,8 @@ bool MainWindowEventFilter::eventFilter(QObject* watched, QEvent* event)
 
     auto eventType = event->type();
     if (eventType == QEvent::MouseButtonPress) {
+#if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
+        // startSystemMove was introduced in Qt 5.15
         auto mouseEvent = dynamic_cast<QMouseEvent*>(event);
         if (watched == mainWindow->m_ui->menubar) {
             if (!mainWindow->m_ui->menubar->actionAt(mouseEvent->pos())) {
@@ -2150,6 +2164,7 @@ bool MainWindowEventFilter::eventFilter(QObject* watched, QEvent* event)
                 return true;
             }
         }
+#endif
     } else if (eventType == QEvent::KeyRelease) {
         if (watched == mainWindow) {
             auto keyEvent = dynamic_cast<QKeyEvent*>(event);
@@ -2159,6 +2174,9 @@ bool MainWindowEventFilter::eventFilter(QObject* watched, QEvent* event)
                 menubar->setVisible(!menubar->isVisible());
                 if (menubar->isVisible()) {
                     menubar->setActiveAction(mainWindow->m_ui->menuFile->menuAction());
+                    m_menubarTimer.start();
+                } else {
+                    m_menubarTimer.stop();
                 }
                 return false;
             }
@@ -2167,5 +2185,3 @@ bool MainWindowEventFilter::eventFilter(QObject* watched, QEvent* event)
 
     return QObject::eventFilter(watched, event);
 }
-
-#endif

src/gui/MainWindow.h

@@ -206,16 +206,17 @@ private slots:
     friend class MainWindowEventFilter;
 };
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
 class MainWindowEventFilter : public QObject
 {
     Q_OBJECT
 
 public:
     explicit MainWindowEventFilter(QObject* parent);
     bool eventFilter(QObject* watched, QEvent* event) override;
+
+private:
+    QTimer m_menubarTimer;
 };
-#endif
 
 /**
  * Return instance of MainWindow created on app load