Make simulator listeners safe against multiple starts

refs #909

src/blackcore/simulator.cpp

@@ -83,4 +83,18 @@ namespace BlackCore
         return m_info.toQString();
     }
 
+    void ISimulatorListener::start()
+    {
+        if (m_isRunning) { return; }
+        m_isRunning = true;
+        startImpl();
+    }
+
+    void ISimulatorListener::stop()
+    {
+        if(!m_isRunning) { return; }
+        stopImpl();
+        m_isRunning = false;
+    }
+
 } // namespace

src/blackcore/simulator.h

@@ -255,17 +255,25 @@ namespace BlackCore
 
     public slots:
         //! Start listening for the simulator to start.
-        virtual void start() = 0;
+        void start();
 
         //! Stops listening.
-        virtual void stop() = 0;
+        void stop();
 
     signals:
         //! Emitted when the listener discovers the simulator running.
         void simulatorStarted(const BlackMisc::Simulation::CSimulatorPluginInfo &info);
 
+    protected:
+        //! Plugin specific implementation to start listener
+        virtual void startImpl() = 0;
+
+        //! Plugin specific implementation to stop listener
+        virtual void stopImpl() = 0;
+
     private:
         BlackMisc::Simulation::CSimulatorPluginInfo m_info;
+        bool m_isRunning = false;
     };
 
     //! Factory pattern class to create instances of ISimulator

src/plugins/simulator/fs9/simulatorfs9.cpp

@@ -448,13 +448,13 @@ namespace BlackSimPlugin
             });
         }
 
-        void CSimulatorFs9Listener::start()
+        void CSimulatorFs9Listener::startImpl()
         {
             m_isStarted = false;
             m_timer->start();
         }
 
-        void CSimulatorFs9Listener::stop()
+        void CSimulatorFs9Listener::stopImpl()
         {
             m_timer->stop();
         }

src/plugins/simulator/fs9/simulatorfs9.h

@@ -117,12 +117,12 @@ namespace BlackSimPlugin
                                   const QSharedPointer<CFs9Host> &fs9Host,
                                   const QSharedPointer<CLobbyClient> &lobbyClient);
 
-        public slots:
+        protected:
-            //! \copydoc BlackCore::ISimulatorListener::start
+            //! \copydoc BlackCore::ISimulatorListener::startImpl
-            virtual void start() override;
+            virtual void startImpl() override;
 
-            //! \copydoc BlackCore::ISimulatorListener::stop
+            //! \copydoc BlackCore::ISimulatorListener::stopImpl
-            virtual void stop() override;
+            virtual void stopImpl() override;
 
         private:
             QTimer *m_timer = nullptr;

src/plugins/simulator/fsxcommon/simulatorfsxcommon.cpp

@@ -1334,7 +1334,7 @@ namespace BlackSimPlugin
             connect(m_timer, &QTimer::timeout, this, &CSimulatorFsxCommonListener::checkConnection);
         }
 
-        void CSimulatorFsxCommonListener::start()
+        void CSimulatorFsxCommonListener::startImpl()
         {
             m_simulatorVersion.clear();
             m_simConnectVersion.clear();
@@ -1343,7 +1343,7 @@ namespace BlackSimPlugin
             m_timer->start();
         }
 
-        void CSimulatorFsxCommonListener::stop()
+        void CSimulatorFsxCommonListener::stopImpl()
         {
             m_timer->stop();
         }

src/plugins/simulator/fsxcommon/simulatorfsxcommon.h

@@ -295,12 +295,12 @@ namespace BlackSimPlugin
             //! \copydoc BlackCore::ISimulatorListener::backendInfo
             virtual QString backendInfo() const override;
 
-        public slots:
+        protected:
-            //! \copydoc BlackCore::ISimulatorListener::start
+            //! \copydoc BlackCore::ISimulatorListener::startImpl
-            virtual void start() override;
+            virtual void startImpl() override;
 
-            //! \copydoc BlackCore::ISimulatorListener::stop
+            //! \copydoc BlackCore::ISimulatorListener::stopImpl
-            virtual void stop() override;
+            virtual void stopImpl() override;
 
         protected:
             //! Test if connection can be established

src/plugins/simulator/xplane/simulatorxplane.cpp

@@ -707,7 +707,7 @@ namespace BlackSimPlugin
         CSimulatorXPlaneListener::CSimulatorXPlaneListener(const CSimulatorPluginInfo &info): ISimulatorListener(info)
         { }
 
-        void CSimulatorXPlaneListener::start()
+        void CSimulatorXPlaneListener::startImpl()
         {
             if (m_watcher) { return; } // already started
             if (isXBusRunning())
@@ -723,7 +723,7 @@ namespace BlackSimPlugin
             }
         }
 
-        void CSimulatorXPlaneListener::stop()
+        void CSimulatorXPlaneListener::stopImpl()
         {
             if (m_watcher)
             {

src/plugins/simulator/xplane/simulatorxplane.h

@@ -204,12 +204,12 @@ namespace BlackSimPlugin
             //! Constructor
             CSimulatorXPlaneListener(const BlackMisc::Simulation::CSimulatorPluginInfo &info);
 
-        public slots:
+        protected:
-            //! \copydoc BlackCore::ISimulatorListener::start
+            //! \copydoc BlackCore::ISimulatorListener::startImpl
-            virtual void start() override;
+            virtual void startImpl() override;
 
-            //! \copydoc BlackCore::ISimulatorListener::stop
+            //! \copydoc BlackCore::ISimulatorListener::stopImpl
-            virtual void stop() override;
+            virtual void stopImpl() override;
 
         private:
             //! \brief Check if XBus service is already registered