astrodatagui: ask before closing in all occasions

astrodatagui/AstrodataGUI.py

@@ -30,8 +30,16 @@ class AstrodataGUI(QtWidgets.QMainWindow):
         print(title)
         print(msg)
 
+    def closeEvent(self, event):
+        confirmation = QtWidgets.QMessageBox.question(self, "Confirmation", "Are you sure you want to close the application?",
+                                                      QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No)
+        if confirmation == QtWidgets.QMessageBox.Yes:
+            event.accept()  # Close the app
+        else:
+            event.ignore()  # Don't close the app
+
     def actionExitTriggered(self):
         for starDB in StarDB.getAllInstances():
             starDB.close()
 
-        exit()
+        self.close()