1 files changed, 8 insertions, 1 deletions
diff --git a/src/pvsgui.cpp b/src/pvsgui.cpp
index c2ac3cb..5b11104 100644
--- a/src/pvsgui.cpp
+++ b/src/pvsgui.cpp
@@ -438,13 +438,20 @@ void printVersion()
 
 int main(int argc, char *argv[])
 {
-    QApplication app(argc, argv);
+    QtSingleApplication app(argc, argv);
     QStringList args = app.arguments();
     app.setQuitOnLastWindowClosed(false);
     app.setOrganizationName("openslx");
     app.setOrganizationDomain("openslx.org");
     app.setApplicationName("pvsgui");
 
+    // only one instance should be allowed
+    if (app.sendMessage(""))
+    {
+        qDebug("[PVSGUI] ERROR: Already running. Exiting");
+        return 0;
+    }
+
     // use system locale as language to translate gui
     QTranslator translator;
     translator.load(":pvsgui");