refs #431, infinite recursion in driver unload

* Trivial changes to avoid changedStatus signal when nothing changed
* Do not reload plugin when already loaded

src/blackcore/context_simulator_impl.cpp

@@ -35,6 +35,7 @@ namespace BlackCore
         IContextSimulator(mode, runtime),
         m_mapper(new QSignalMapper(this))
     {
+        this->setObjectName("CContextSimulator");
         findSimulatorPlugins();
         // Maps listener instance
         connect(m_mapper, static_cast<void (QSignalMapper::*)(QObject *)>(&QSignalMapper::mapped), this, &CContextSimulator::ps_simulatorStarted);
@@ -363,6 +364,12 @@ namespace BlackCore
             return false;
         }
 
+        // Is the plugin already loaded?
+        if (m_simulatorPlugin && m_simulatorPlugin->info == simulatorInfo)
+        {
+            return true;
+        }
+
         ISimulatorFactory *factory = getSimulatorFactory(simulatorInfo);
         Q_ASSERT(factory);
 
@@ -416,6 +423,7 @@ namespace BlackCore
         settingsChanged(static_cast<uint>(IContextSettings::SettingsSimulator));
 
         // try to connect
+        //! \todo #417: we want to change this to connectTo, as the listener already checks the avialability of the simulator
         m_simulatorPlugin->simulator->asyncConnectTo();
 
         if (m_simulatorPlugin) // can be already nullptr if connectTo() is synchronous and fails
@@ -541,8 +549,8 @@ namespace BlackCore
 
     void CContextSimulator::unloadSimulatorPlugin()
     {
-        if (m_simulatorPlugin)
+        if (!m_simulatorPlugin) { return; }
-        {
+
         // depending on shutdown order, network might already have been deleted
         emit simulatorPluginChanged(CSimulatorPluginInfo());
 
@@ -560,7 +568,6 @@ namespace BlackCore
         m_simulatorPlugin->simulator = nullptr;
         m_simulatorPlugin = nullptr;
     }
-    }
 
     void CContextSimulator::ps_addRemoteAircraft(const CSimulatedAircraft &remoteAircraft)
     {

src/blackcore/simulator.cpp

@@ -45,9 +45,13 @@ namespace BlackCore
         }
     }
 
-    void ISimulator::emitSimulatorCombinedStatus()
+    void ISimulator::emitSimulatorCombinedStatus(int oldStatus)
     {
-        emit simulatorStatusChanged(getSimulatorStatus());
+        int newStatus = getSimulatorStatus();
+        if (oldStatus != newStatus)
+        {
+            emit simulatorStatusChanged(newStatus);
+        }
     }
 
     ISimulatorListener::ISimulatorListener(QObject *parent) : QObject(parent)

src/blackcore/simulator.h

@@ -73,6 +73,7 @@ namespace BlackCore
         virtual bool connectTo() = 0;
 
         //! Connect asynchronously to simulator
+        //! \deprecated #417
         virtual void asyncConnectTo() = 0;
 
         //! Disconnect from simulator
@@ -226,8 +227,9 @@ namespace BlackCore
         virtual int physicallyRemoveAllRemoteAircraft() = 0;
 
         //! Emit the combined status
+        //! \param oldStatus optionally one can capture and provide the old status for comparison. In case of equal status values no signal will be sent
         //! \sa simulatorStatusChanged;
-        void emitSimulatorCombinedStatus();
+        void emitSimulatorCombinedStatus(int oldStatus = -1);
     };
 
     //! Interface to a simulator listener.

src/plugins/simulator/fs9/simulator_fs9.cpp

@@ -96,7 +96,7 @@ namespace BlackSimPlugin
 
         bool CSimulatorFs9::disconnectFrom()
         {
-            if (!m_simConnected) return true;
+            if (!m_simConnected) { return true; }
 
             // Don't forward messages when disconnected
             disconnect(m_connectionHostMessages);

src/plugins/simulator/fsx/simulator_fsx.cpp

@@ -80,12 +80,13 @@ namespace BlackSimPlugin
         bool CSimulatorFsx::connectTo()
         {
             if (m_simConnected) { return true; }
+            int oldStatus = getSimulatorStatus();
             if (FAILED(SimConnect_Open(&m_hSimConnect, BlackMisc::CProject::systemNameAndVersionChar(), nullptr, 0, 0, 0)))
             {
                 m_simConnected = false;
                 m_simPaused = false;
                 m_simSimulating = false;
-                emitSimulatorCombinedStatus();
+                emitSimulatorCombinedStatus(oldStatus);
                 return false;
             }
             else
@@ -96,7 +97,7 @@ namespace BlackSimPlugin
             initWhenConnected();
             m_simconnectTimerId = startTimer(10);
             m_simConnected = true;
-            emitSimulatorCombinedStatus();
+            emitSimulatorCombinedStatus(oldStatus);
             return true;
         }
 
@@ -352,8 +353,9 @@ namespace BlackSimPlugin
 
         void CSimulatorFsx::onSimStopped()
         {
+            int oldStatus = getSimulatorStatus();
             m_simSimulating = false;
-            emitSimulatorCombinedStatus();
+            emitSimulatorCombinedStatus(oldStatus);
         }
 
         void CSimulatorFsx::onSimFrame()

src/plugins/simulator/fsx/simulator_fsx_simconnectproc.cpp

@@ -84,8 +84,11 @@ namespace BlackSimPlugin
                     case SystemEventPause:
                         {
                             bool p = event->dwData ? true : false;
+                            if (simulatorFsx->m_simPaused != p)
+                            {
                                 simulatorFsx->m_simPaused = p;
                                 simulatorFsx->emitSimulatorCombinedStatus();
+                            }
                             break;
                         }
                     default:

src/plugins/simulator/xplane/simulator_xplane.cpp

@@ -193,6 +193,7 @@ namespace BlackSimPlugin
 
         bool CSimulatorXPlane::disconnectFrom()
         {
+            if (!this->isConnected()) { return true; } // avoid emit if already disconnected
             if (m_traffic)
             {
                 m_traffic->cleanup();