feat(xswiftbus): Expose callsign as dataref

Fixes #379

src/core/context/contextsimulatorimpl.cpp

@@ -802,12 +802,15 @@ namespace swift::core::context
     {
         Q_UNUSED(from)
         SWIFT_VERIFY_X(this->getIContextNetwork(), Q_FUNC_INFO, "Missing network context");
+        SWIFT_VERIFY_X(this->getIContextOwnAircraft(), Q_FUNC_INFO, "Missing own aircraft context");
         if (to.isConnected() && this->getIContextNetwork())
         {
             m_networkSessionId = this->getIContextNetwork()->getConnectedServer().getServerSessionId(false);
             if (m_simulatorPlugin.second) // check in case the plugin has been unloaded
             {
                 m_simulatorPlugin.second->setFlightNetworkConnected(true);
+                m_simulatorPlugin.second->setOwnCallsign(
+                    this->getIContextOwnAircraft()->getOwnAircraft().getCallsign());
             }
         }
         else if (to.isDisconnected())
@@ -821,6 +824,7 @@ namespace swift::core::context
             {
                 m_simulatorPlugin.second->removeAllRemoteAircraft(); // also removes aircraft
                 m_simulatorPlugin.second->setFlightNetworkConnected(false);
+                m_simulatorPlugin.second->setOwnCallsign({});
             }
         }
     }

src/core/simulator.cpp

@@ -119,6 +119,12 @@ namespace swift::core
 
     void ISimulator::setFlightNetworkConnected(bool connected) { m_networkConnected = connected; }
 
+    void ISimulator::setOwnCallsign(const CCallsign &callsign)
+    {
+        Q_UNUSED(callsign)
+        // void
+    }
+
     void ISimulator::clearAllRemoteAircraftData()
     {
         // rendering related stuff

src/core/simulator.h

@@ -152,6 +152,9 @@ namespace swift::core
         //! \sa ISimulator::isFlightNetworkConnected
         virtual void setFlightNetworkConnected(bool connected);
 
+        //! Own callsign has changed
+        virtual void setOwnCallsign(const swift::misc::aviation::CCallsign &callsign);
+
         //! Is the flight network connected
         bool isFlightNetworkConnected() const { return m_networkConnected; }
 

src/plugins/simulator/xplane/simulatorxplane.cpp

@@ -219,6 +219,12 @@ namespace swift::simplugin::xplane
         CSimulatorPluginCommon::setFlightNetworkConnected(connected);
     }
 
+    void CSimulatorXPlane::setOwnCallsign(const CCallsign &callsign)
+    {
+        m_serviceProxy->setOwnCallsign(callsign.asString());
+        CSimulatorPluginCommon::setOwnCallsign(callsign);
+    }
+
     bool CSimulatorXPlane::isSuspiciousTerrainValue(const CElevationPlane &elevation)
     {
         if (!elevation.hasMSLGeodeticHeight()) { return true; }

src/plugins/simulator/xplane/simulatorxplane.h

@@ -150,6 +150,7 @@ namespace swift::simplugin::xplane
                                                 const swift::misc::aviation::CCallsign &callsign,
                                                 bool isWater) override;
         void setFlightNetworkConnected(bool connected) override;
+        void setOwnCallsign(const swift::misc::aviation::CCallsign &callsign) override;
         //! @}
 
         //! \copydoc swift::misc::simulation::ISimulationEnvironmentProvider::requestElevation

src/plugins/simulator/xplane/xswiftbusserviceproxy.cpp

@@ -363,6 +363,11 @@ namespace swift::simplugin::xplane
         m_dbusInterface->callDBus(QLatin1String("setFlightNetworkConnected"), connected);
     }
 
+    void CXSwiftBusServiceProxy::setOwnCallsign(const QString &callsign)
+    {
+        m_dbusInterface->callDBus(QLatin1String("setOwnCallsign"), callsign);
+    }
+
     double CXSwiftBusServiceProxy::getLatitudeDeg() const
     {
         return m_dbusInterface->callDBusRet<double>(QLatin1String("getLatitudeDeg"));

src/plugins/simulator/xplane/xswiftbusserviceproxy.h

@@ -215,6 +215,9 @@ namespace swift::simplugin::xplane
         //! \copydoc XSwiftBus::CService::setFlightNetworkConnected
         void setFlightNetworkConnected(bool connected);
 
+        //! \copydoc XSwiftBus::CService::setOwnCallsign
+        void setOwnCallsign(const QString &callsign);
+
         //! @{
         //! \copydoc XSwiftBus::CService::getLatitudeDeg
         double getLatitudeDeg() const;

src/xswiftbus/custom_datarefs.h

@@ -11,12 +11,17 @@ namespace XSwiftBus
     {
         //! 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;
+
+    //! Current callsign
+    struct TSwiftCallsign
+    {
+        //! Dataref name
+        static constexpr const char *name() { return "org/swift-project/xswiftbus/callsign"; }
+        //! Dataref type
+        using type = std::string;
     };
 
 } // namespace XSwiftBus

src/xswiftbus/datarefs.h

@@ -9,8 +9,10 @@
 #include <XPLM/XPLMDataAccess.h>
 #include <XPLM/XPLMUtilities.h>
 
+#include <algorithm>
 #include <array>
 #include <cassert>
+#include <cstring>
 #include <string>
 
 // Avoid checking large auto-generated header with cppcheck
@@ -223,8 +225,13 @@ namespace XSwiftBus
         XPLMDataRef m_ref;
     };
 
+    /* Helper to conditionally fail compilation if no matching constexpr if case is found */
+    template <class...>
+    constexpr bool dependent_false = false;
+
     /*!
      * Class providing a custom variable + dataref
+     * \hint Currently only readable int and std::string datarefs are supported
      * \tparam DataRefTraits The trait class representing the dataref.
      */
     template <class DataRefTraits>
@@ -236,10 +243,17 @@ namespace XSwiftBus
         {
             if constexpr (std::is_same_v<typename DataRefTraits::type, int>)
             {
-                m_ref = XPLMRegisterDataAccessor(DataRefTraits::name(), xplmType_Int, 0, read, NULL, NULL, NULL, NULL,
+                m_ref = XPLMRegisterDataAccessor(DataRefTraits::name(), xplmType_Int, 0, readInt, nullptr, nullptr,
-                                                 NULL, NULL, NULL, NULL, NULL, NULL, NULL, this, NULL);
+                                                 nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
+                                                 nullptr, this, nullptr);
             }
-            else { XPLMDebugString("Unsupported custom dataref type\n"); }
+            else if constexpr (std::is_same_v<typename DataRefTraits::type, std::string>)
+            {
+                m_ref = XPLMRegisterDataAccessor(DataRefTraits::name(), xplmType_Data, 0, nullptr, nullptr, nullptr,
+                                                 nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
+                                                 readData, nullptr, this, nullptr);
+            }
+            else { static_assert(dependent_false<typename DataRefTraits::type>, "Unsupported custom dataref type"); }
             if (!m_ref)
             {
                 XPLMDebugString("Missing dataref:");
@@ -257,11 +271,27 @@ namespace XSwiftBus
             if (m_ref) { XPLMUnregisterDataAccessor(m_ref); }
         }
 
-        static typename DataRefTraits::type read(void *refcon)
+        static typename DataRefTraits::type readInt(void *refcon)
         {
             return reinterpret_cast<CustomDataRef *>(refcon)->get();
         }
 
+        static int readData(void *refcon, void *out, int offset, int max_length)
+        {
+            if constexpr (std::is_same_v<typename DataRefTraits::type, std::string>)
+            {
+                std::string_view sv(reinterpret_cast<CustomDataRef *>(refcon)->get());
+                const size_t start = std::clamp<size_t>(offset, 0, sv.size());
+                const size_t remaining_length = sv.size() - start;
+                const auto len = std::min(static_cast<size_t>(max_length), remaining_length);
+                sv = sv.substr(start, len);
+                std::memcpy(out, sv.data(), len);
+                return static_cast<int>(len);
+            }
+
+            return -1; // should never be reached
+        }
+
         //! True if the dataref exists
         bool isValid() const { return m_ref != nullptr; }
 
@@ -269,7 +299,7 @@ namespace XSwiftBus
         void set(typename DataRefTraits::type val) { m_datarefVal = val; }
 
         //! Get the value
-        typename DataRefTraits::type get() const { return m_datarefVal; }
+        const typename DataRefTraits::type &get() const { return m_datarefVal; }
 
         XPLMDataRef m_ref;
         typename DataRefTraits::type m_datarefVal;

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

@@ -116,6 +116,9 @@ R"XML(<node>
     <method name="setFlightNetworkConnected">
       <arg type="b" direction="in"/>
     </method>
+    <method name="setOwnCallsign">
+      <arg type="s" direction="in"/>
+    </method>
     <method name="getLatitudeDeg">
       <arg type="d" direction="out"/>
     </method>

src/xswiftbus/service.cpp

@@ -94,6 +94,7 @@ namespace XSwiftBus
         this->updateMessageBoxFromSettings();
         m_framePeriodSampler->show();
         m_swiftNetworkConnected.set(0);
+        m_swiftCallsign.set("");
     }
 
     // Explicitly in cpp file to allow use of forward declaration
@@ -139,6 +140,8 @@ namespace XSwiftBus
 
     void CService::setFlightNetworkConnected(bool connected) { m_swiftNetworkConnected.set(connected); }
 
+    void CService::setOwnCallsign(const std::string &callsign) { m_swiftCallsign.set(callsign); }
+
     void CService::addTextMessage(const std::string &text, double red, double green, double blue)
     {
         if (text.empty()) { return; }
@@ -520,6 +523,14 @@ namespace XSwiftBus
                 message.getArgument(connected);
                 queueDBusCall([=]() { setFlightNetworkConnected(connected); });
             }
+            else if (message.getMethodName() == "setOwnCallsign")
+            {
+                maybeSendEmptyDBusReply(wantsReply, sender, serial);
+                std::string callsign;
+                message.beginArgumentRead();
+                message.getArgument(callsign);
+                queueDBusCall([=]() { setOwnCallsign(callsign); });
+            }
             else if (message.getMethodName() == "getLatitudeDeg")
             {
                 queueDBusCall([=]() { sendDBusReply(sender, serial, getLatitudeDeg()); });

src/xswiftbus/service.h

@@ -123,6 +123,9 @@ namespace XSwiftBus
         //! Set the current connection state
         void setFlightNetworkConnected(bool connected);
 
+        //! Set the current own callsign
+        void setOwnCallsign(const std::string &callsign);
+
         //! Get aircraft latitude in degrees
         double getLatitudeDeg() const { return m_latitude.get(); }
 
@@ -354,6 +357,7 @@ namespace XSwiftBus
         int m_sceneryWasLoading = 0;
 
         CustomDataRef<TSwiftNetworkConnected> m_swiftNetworkConnected;
+        CustomDataRef<TSwiftCallsign> m_swiftCallsign;
         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;