BrowserWindow: Add aboutToClose signal

src/lib/app/browserwindow.cpp

@@ -1508,6 +1508,8 @@ void BrowserWindow::closeEvent(QCloseEvent* event)
         }
     }
 
+    emit aboutToClose();
+
     saveSettings();
     mApp->closedWindowsManager()->saveWindow(this);
 

src/lib/app/browserwindow.h

@@ -125,6 +125,7 @@ public:
 
 signals:
     void startingCompleted();
+    void aboutToClose();
 
 public slots:
     void goHome();

src/lib/app/mainapplication.cpp

@@ -690,6 +690,10 @@ void MainApplication::quitApplication()
         return;
     }
 
+    for (BrowserWindow *window : qAsConst(m_windows)) {
+        emit window->aboutToClose();
+    }
+
     if (m_sessionManager && m_windows.count() > 0) {
         m_sessionManager->autoSaveLastSession();
     }