feat: Add custom X-Plane dataref for connection state

Fixes #304

Author: ltoenning

src/plugins/simulator/xplane/simulatorxplane.cpp

@@ -217,6 +217,7 @@ namespace swift::simplugin::xplane
     void CSimulatorXPlane::setFlightNetworkConnected(bool connected)
     {
         if (connected && !this->isShuttingDownOrDisconnected()) { m_serviceProxy->resetFrameTotals(); }
+        m_serviceProxy->setFlightNetworkConnected(connected);
         CSimulatorPluginCommon::setFlightNetworkConnected(connected);
     }
 

src/plugins/simulator/xplane/xswiftbusserviceproxy.cpp

@@ -368,6 +368,11 @@ namespace swift::simplugin::xplane
 
     void CXSwiftBusServiceProxy::resetFrameTotals() { m_dbusInterface->callDBus(QLatin1String("resetFrameTotals")); }
 
+    void CXSwiftBusServiceProxy::setFlightNetworkConnected(bool connected)
+    {
+        m_dbusInterface->callDBus(QLatin1String("setFlightNetworkConnected"), connected);
+    }
+
     double CXSwiftBusServiceProxy::getLatitudeDeg() const
     {
         return m_dbusInterface->callDBusRet<double>(QLatin1String("getLatitudeDeg"));

src/plugins/simulator/xplane/xswiftbusserviceproxy.h

@@ -219,6 +219,9 @@ namespace swift::simplugin::xplane
         //! \copydoc XSwiftBus::CService::resetFrameTotals
         void resetFrameTotals();
 
+        //! \copydoc XSwiftBus::CService::setFlightNetworkConnected
+        void setFlightNetworkConnected(bool connected);
+
         //! @{
         //! \copydoc XSwiftBus::CService::getLatitudeDeg
         double getLatitudeDeg() const;

src/xswiftbus/CMakeLists.txt

@@ -12,6 +12,7 @@ add_library(xswiftbus SHARED
         command.h
         config.cpp
         config.h
+        custom_datarefs.h
         datarefs.h
         dbuscallbacks.h
         dbusconnection.cpp

src/xswiftbus/custom_datarefs.h

@@ -0,0 +1,24 @@
+// SPDX-FileCopyrightText: Copyright (C) swift Project Community / Contributors
+// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-swift-pilot-client-1
+
+#ifndef SWIFT_SIM_XSWIFTBUS_CUSTOM_DATAREFS_H
+#define SWIFT_SIM_XSWIFTBUS_CUSTOM_DATAREFS_H
+
+namespace XSwiftBus
+{
+    //! Is swift connected to a network?
+    struct TSwiftNetworkConnected
+    {
+        //! Dataref name
+        static constexpr const char *name() { return "org/swift-project/xswiftbus/connected"; }
+        //! Can be written to?
+        static constexpr bool writable = false;
+        //! Dataref type
+        using type = int;
+        //! Not an array dataref
+        static constexpr bool is_array = false;
+    };
+
+} // namespace XSwiftBus
+
+#endif // SWIFT_SIM_XSWIFTBUS_CUSTOM_DATAREFS_H

src/xswiftbus/datarefs.h

@@ -223,6 +223,55 @@ namespace XSwiftBus
         XPLMDataRef m_ref;
     };
 
+    /*!
+     * Class providing a custom variable + dataref
+     * \tparam DataRefTraits The trait class representing the dataref.
+     */
+    template <class DataRefTraits>
+    class CustomDataRef
+    {
+    public:
+        //! Constructor
+        CustomDataRef()
+        {
+            if constexpr (std::is_same_v<typename DataRefTraits::type, int>)
+            {
+                m_ref = XPLMRegisterDataAccessor(DataRefTraits::name(), xplmType_Int, 0, read, NULL, NULL, NULL, NULL,
+                                                 NULL, NULL, NULL, NULL, NULL, NULL, NULL, this, NULL);
+            }
+            else { static_assert(false, "Unsupported type"); }
+            if (!m_ref)
+            {
+                XPLMDebugString("Missing dataref:");
+                XPLMDebugString(DataRefTraits::name());
+                XPLMDebugString("\n");
+            }
+        }
+
+        CustomDataRef(const CustomDataRef &) = delete;
+        CustomDataRef &operator=(const CustomDataRef &) = delete;
+        CustomDataRef(CustomDataRef &&other) = default;
+        CustomDataRef &operator=(CustomDataRef &&other) = default;
+        ~CustomDataRef() { XPLMUnregisterDataAccessor(m_ref); }
+
+        static typename DataRefTraits::type read(void *refcon)
+        {
+            return reinterpret_cast<CustomDataRef *>(refcon)->get();
+        }
+
+        //! True if the dataref exists
+        bool isValid() const { return m_ref != nullptr; }
+
+        //! Set the value
+        void set(typename DataRefTraits::type val) { m_datarefVal = val; }
+
+        //! Get the value
+        typename DataRefTraits::type get() const { return m_datarefVal; }
+
+        XPLMDataRef m_ref;
+        typename DataRefTraits::type m_datarefVal;
+    };
+
     template <>
     inline void DataRefImpl::implSet<int>(int d)
     {

src/xswiftbus/org.swift_project.xswiftbus.service.xml

@@ -115,6 +115,9 @@ R"XML(<node>
     </method>
     <method name="resetFrameTotals">
     </method>
+    <method name="setFlightNetworkConnected">
+      <arg type="b" direction="in"/>
+    </method>
     <method name="getLatitudeDeg">
       <arg type="d" direction="out"/>
     </method>

src/xswiftbus/service.cpp

@@ -94,6 +94,7 @@ namespace XSwiftBus
         this->updateAirportsInRange();
         this->updateMessageBoxFromSettings();
         m_framePeriodSampler->show();
+        m_swiftNetworkConnected.set(0);
     }
 
     CService::~CService() = default;
@@ -136,6 +137,8 @@ namespace XSwiftBus
         }
     }
 
+    void CService::setFlightNetworkConnected(bool connected) { m_swiftNetworkConnected.set(connected); }
+
     void CService::addTextMessage(const std::string &text, double red, double green, double blue)
     {
         if (text.empty()) { return; }
@@ -550,6 +553,14 @@ namespace XSwiftBus
                 maybeSendEmptyDBusReply(wantsReply, sender, serial);
                 queueDBusCall([=]() { resetFrameTotals(); });
             }
+            else if (message.getMethodName() == "setFlightNetworkConnected")
+            {
+                maybeSendEmptyDBusReply(wantsReply, sender, serial);
+                bool connected = false;
+                message.beginArgumentRead();
+                message.getArgument(connected);
+                queueDBusCall([=]() { setFlightNetworkConnected(connected); });
+            }
             else if (message.getMethodName() == "getLatitudeDeg")
             {
                 queueDBusCall([=]() { sendDBusReply(sender, serial, getLatitudeDeg()); });

src/xswiftbus/service.h

@@ -16,6 +16,7 @@
 #include "messages.h"
 #include "navdatareference.h"
 #include "terrainprobe.h"
+#include "custom_datarefs.h"
 #include <XPLM/XPLMNavigation.h>
 #include <string>
 #include <chrono>
@@ -123,6 +124,9 @@ namespace XSwiftBus
         //! Reset the monitoring of total miles and minutes lost due to low frame rate.
         void resetFrameTotals();
 
+        //! Set the current connection state
+        void setFlightNetworkConnected(bool connected);
+
         //! Get aircraft latitude in degrees
         double getLatitudeDeg() const { return m_latitude.get(); }
 
@@ -361,6 +365,7 @@ namespace XSwiftBus
         DataRef<xplane::data::sim::graphics::scenery::async_scenery_load_in_progress> m_sceneryIsLoading;
         int m_sceneryWasLoading = 0;
 
+        CustomDataRef<TSwiftNetworkConnected> m_swiftNetworkConnected;
         StringDataRef<xplane::data::sim::aircraft::view::acf_livery_path> m_liveryPath;
         StringDataRef<xplane::data::sim::aircraft::view::acf_ICAO> m_icao;
         StringDataRef<xplane::data::sim::aircraft::view::acf_descrip> m_descrip;