Prevent session managers from forcefully restoring the app

Author: timschneeb

src/MainWindow.cpp

@@ -51,6 +51,7 @@
 #include <QInputDialog>
 #include <QMenu>
 #include <QMessageBox>
+#include <QSessionManager>
 #include <QWhatsThis>
 
 using namespace std;
@@ -434,11 +435,16 @@ void MainWindow::closeEvent(QCloseEvent *event)
 
 #endif
 
-    if (_trayIcon->isVisible())
+    if (_trayIcon->isVisible() && !_allowCloseEvent)
     {
         hide();
         event->ignore();
     }
+    else
+    {
+        event->accept();
+        QMainWindow::closeEvent(event);
+    }
 }
 
 void MainWindow::resizeEvent(QResizeEvent *event)
@@ -447,6 +453,11 @@ void MainWindow::resizeEvent(QResizeEvent *event)
     AppConfig::instance().setBytes(AppConfig::LastWindowGeometry, saveGeometry());
 }
 
+void MainWindow::shutdown()
+{
+    _allowCloseEvent = true;
+    this->close();
+}
 
 // Systray
 void MainWindow::raiseWindow()
@@ -1280,3 +1291,4 @@ void MainWindow::launchFirstRunSetup()
         });
     });
 }
+

src/MainWindow.h

@@ -71,6 +71,7 @@ public slots:
     void onRelinkRequested();
     void raiseWindow();
     void launchFirstRunSetup();
+    void shutdown();
 
 private slots:
     void applyConfig();
@@ -125,6 +126,7 @@ private slots:
     IAudioService* _audioService       = nullptr;
 
     bool _blockApply                   = false;
+    bool _allowCloseEvent = false;
 
     QString _currentImpulseResponse    = "";
     QString _currentVdc                = "";

src/main.cpp

@@ -10,6 +10,7 @@
 #include <QStyle>
 #include <QScopeGuard>
 #include <QTextStream>
+#include <QSessionManager>
 
 #define FORCE_CRASH_HANDLER
 
@@ -112,8 +113,13 @@ int main(int   argc,
     Log::information("Application version: " + QString(APP_VERSION_FULL));
     Log::information("Qt library version: " + QString(qVersion()));
 
-
-    Log::debug("Launched by system session manager: " + QString(qApp->isSessionRestored() ? "yes" : "no"));
+    Log::debug("Launched by system session manager: " + QString(qApp->isSessionRestored() ? "yes" : "no")); /* unreliable */
+    QGuiApplication::setFallbackSessionManagementEnabled(false);   
+    QObject::connect(qApp, &QGuiApplication::saveStateRequest, qApp, [](QSessionManager &manager){
+        // Block session restore requests
+        manager.setRestartHint(QSessionManager::RestartNever);
+        manager.release();
+    }, Qt::DirectConnection);
 
     QFile id("/var/lib/dbus/machine-id");
     if(id.open(QFile::ReadOnly | QFile::Text))
@@ -146,7 +152,6 @@ int main(int   argc,
     DspConfig::instance(parser.isSet(watch));
     AppConfig::instance().set(AppConfig::ExecutablePath, QString::fromLocal8Bit(exepath));
 
-    QApplication::setFallbackSessionManagementEnabled(false);
     MainWindow w(parser.isSet(tray));
 
     QObject::connect(instanceMonitor, &SingleInstanceMonitor::raiseWindow, &w, &MainWindow::raiseWindow);
@@ -160,7 +165,7 @@ int main(int   argc,
 			)
 		);
 	w.setWindowFlags(Qt::WindowContextHelpButtonHint | Qt::WindowCloseButtonHint);
-	w.hide();
+    w.hide();
 
     if (!parser.isSet(tray))
 	{
@@ -170,7 +175,7 @@ int main(int   argc,
         {
             w.show();
         }
-	}
+    }
 
 	return QApplication::exec();
 }