Add a per-model execution-enable property

src/input_output/FGInputType.cpp

@@ -50,8 +50,9 @@ CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 FGInputType::FGInputType(FGFDMExec* fdmex, bool isEnabled) :
-  FGModel(fdmex), enabled(isEnabled)
+  FGModel(fdmex, "")
 {
+  enabled = isEnabled;
   Debug(0);
 }
 
@@ -100,7 +101,6 @@ bool FGInputType::InitModel(void)
 bool FGInputType::Run(bool Holding)
 {
   if (FGModel::Run(Holding)) return true;
-  if (!enabled) return true;
 
   RunPreFunctions();
   Read(Holding);

src/input_output/FGInputType.h

@@ -130,7 +130,6 @@ class FGInputType : public FGModel
 
 protected:
   unsigned int InputIdx;
-  bool enabled;
 
   void Debug(int from) override;
 };

src/input_output/FGOutputType.cpp

@@ -54,9 +54,8 @@ CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 FGOutputType::FGOutputType(FGFDMExec* fdmex) :
-  FGModel(fdmex),
-  SubSystems(0),
-  enabled(true)
+  FGModel(fdmex, ""),
+  SubSystems(0)
 {
   Aerodynamics = FDMExec->GetAerodynamics();
   Auxiliary = FDMExec->GetAuxiliary();
@@ -186,7 +185,6 @@ bool FGOutputType::InitModel(void)
 bool FGOutputType::Run(bool Holding)
 {
   if (FGModel::Run(Holding)) return true;
-  if (!enabled) return true;
 
   RunPreFunctions();
   Print();

src/input_output/FGOutputType.h

@@ -196,7 +196,6 @@ class FGOutputType : public FGModel
   int SubSystems;
   std::vector <FGPropertyValue*> OutputParameters;
   std::vector <std::string> OutputCaptions;
-  bool enabled;
 
   std::shared_ptr<FGAerodynamics> Aerodynamics;
   std::shared_ptr<FGAuxiliary> Auxiliary;

src/models/FGAccelerations.cpp

@@ -66,10 +66,9 @@ CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 FGAccelerations::FGAccelerations(FGFDMExec* fdmex)
-  : FGModel(fdmex)
+  : FGModel(fdmex, "FGAccelerations")
 {
   Debug(0);
-  Name = "FGAccelerations";
   gravTorque = false;
 
   vPQRidot.InitMatrix();

src/models/FGAerodynamics.cpp

@@ -50,10 +50,8 @@ CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 
-FGAerodynamics::FGAerodynamics(FGFDMExec* FDMExec) : FGModel(FDMExec)
+FGAerodynamics::FGAerodynamics(FGFDMExec* FDMExec) : FGModel(FDMExec, "FGAerodynamics")
 {
-  Name = "FGAerodynamics";
-
   AxisIdx["DRAG"]   = 0;
   AxisIdx["SIDE"]   = 1;
   AxisIdx["LIFT"]   = 2;

src/models/FGAircraft.cpp

@@ -51,9 +51,8 @@ namespace JSBSim {
 CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-FGAircraft::FGAircraft(FGFDMExec* fdmex) : FGModel(fdmex)
+FGAircraft::FGAircraft(FGFDMExec* fdmex) : FGModel(fdmex, "FGAircraft")
 {
-  Name = "FGAircraft";
   WingSpan = 0.0;
   WingArea = 0.0;
   cbar = 0.0;

src/models/FGAtmosphere.cpp

@@ -55,11 +55,9 @@ CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 FGAtmosphere::FGAtmosphere(FGFDMExec* fdmex)
-  : FGModel(fdmex),
+  : FGModel(fdmex, "FGAtmosphere"),
     StdDaySLsoundspeed(sqrt(SHRatio*Reng0*StdDaySLtemperature))
 {
-  Name = "FGAtmosphere";
-
   bind();
   SGPropertyNode* root = PropertyManager->GetNode();
   atmosphere_node = root->getNode("atmosphere");

src/models/FGAuxiliary.cpp

@@ -59,9 +59,8 @@ CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 
-FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex)
+FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex, "FGAuxiliary")
 {
-  Name = "FGAuxiliary";
   pt = FGAtmosphere::StdDaySLpressure;     // ISA SL pressure
   tat = FGAtmosphere::StdDaySLtemperature; // ISA SL temperature
   tatc = RankineToCelsius(tat);

src/models/FGBuoyantForces.cpp

@@ -49,10 +49,8 @@ namespace JSBSim {
 CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-FGBuoyantForces::FGBuoyantForces(FGFDMExec* FDMExec) : FGModel(FDMExec)
+FGBuoyantForces::FGBuoyantForces(FGFDMExec* FDMExec) : FGModel(FDMExec, "FGBuoyantForces")
 {
-  Name = "FGBuoyantForces";
-
   NoneDefined = true;
 
   vTotalForces.InitMatrix();

src/models/FGExternalReactions.cpp

@@ -50,7 +50,7 @@ namespace JSBSim {
 CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-FGExternalReactions::FGExternalReactions(FGFDMExec* fdmex) : FGModel(fdmex)
+FGExternalReactions::FGExternalReactions(FGFDMExec* fdmex) : FGModel(fdmex, "FGExternalReactions")
 {
   Debug(0);
 }

src/models/FGFCS.cpp

@@ -71,10 +71,9 @@ namespace JSBSim {
 CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-FGFCS::FGFCS(FGFDMExec* fdm) : FGModel(fdm), ChannelRate(1)
+FGFCS::FGFCS(FGFDMExec* fdm) : FGModel(fdm, "FGFCS"), ChannelRate(1)
 {
   int i;
-  Name = "FGFCS";
   systype = stFCS;
 
   DaCmd = DeCmd = DrCmd = DfCmd = DsbCmd = DspCmd = 0;

src/models/FGGroundReactions.cpp

@@ -52,12 +52,10 @@ CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 FGGroundReactions::FGGroundReactions(FGFDMExec* fgex) :
-   FGModel(fgex),
+   FGModel(fgex, "FGGroundReactions"),
    FGSurface(fgex),
    DsCmd(0.0)
 {
-  Name = "FGGroundReactions";
-
   bind();
 
   Debug(0);

src/models/FGInertial.cpp

@@ -51,7 +51,7 @@ CLASS IMPLEMENTATION
 
 
 FGInertial::FGInertial(FGFDMExec* fgex)
-  : FGModel(fgex)
+  : FGModel(fgex, "FGInertial")
 {
   Name = "Earth";
 

src/models/FGInput.cpp

@@ -54,9 +54,8 @@ namespace JSBSim {
 CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-FGInput::FGInput(FGFDMExec* fdmex) : FGModel(fdmex)
+FGInput::FGInput(FGFDMExec* fdmex) : FGModel(fdmex, "FGInput")
 {
-  Name = "FGInput";
   enabled = true;
 
   Debug(0);
@@ -142,7 +141,6 @@ bool FGInput::Run(bool Holding)
 {
   if (FDMExec->GetTrimStatus()) return true;
   if (FGModel::Run(Holding)) return true;
-  if (!enabled) return true;
 
   vector<FGInputType*>::iterator it;
   for (it = InputTypes.begin(); it != InputTypes.end(); ++it)

src/models/FGInput.h

@@ -145,7 +145,6 @@ class FGInput : public FGModel
 
 private:
   std::vector<FGInputType*> InputTypes;
-  bool enabled;
 
   void Debug(int from) override;
 };

src/models/FGMassBalance.cpp

@@ -55,9 +55,8 @@ CLASS IMPLEMENTATION
 
 
 FGMassBalance::FGMassBalance(FGFDMExec* fdmex)
-  : FGModel(fdmex)
+  : FGModel(fdmex, "FGMassBalance")
 {
-  Name = "FGMassBalance";
   Weight = EmptyWeight = Mass = 0.0;
 
   vbaseXYZcg.InitMatrix();

src/models/FGModel.cpp

@@ -42,6 +42,7 @@ INCLUDES
 #include "FGFDMExec.h"
 #include "input_output/FGModelLoader.h"
 #include "input_output/FGLog.h"
+#include "input_output/FGPropertyManager.h"
 
 using namespace std;
 
@@ -55,7 +56,8 @@ GLOBAL DECLARATIONS
 CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-FGModel::FGModel(FGFDMExec* fdmex)
+FGModel::FGModel(FGFDMExec* fdmex, const std::string& name)
+ : Name(name)
 {
   FDMExec     = fdmex;
 
@@ -67,6 +69,15 @@ FGModel::FGModel(FGFDMExec* fdmex)
   exe_ctr     = 1;
   rate        = 1;
 
+  // A model that is scheduled by FGFDMExec is named and gets an enable property.
+  // The input and output types are not scheduled: they are instantiated one per
+  // <input> and <output> element, so a shared property path would be tied more
+  // than once. They pass an empty name and are enabled through the per-instance
+  // property that FGOutputType::SetIdx already binds, or through Enable() and
+  // Disable().
+  if (!Name.empty())
+    PropertyManager->Tie("simulation/models/" + Name + "/enabled", &enabled);
+
   Debug(0);
 }
 
@@ -91,12 +102,13 @@ bool FGModel::Run(bool Holding)
 {
   FGModel::Debug(2);
 
-  if (rate == 1) return false; // Fast exit if nothing to do
+  if (rate == 1) return !enabled; // Fast exit if nothing to do
 
   if (exe_ctr >= rate) exe_ctr = 0;
 
-  if (exe_ctr++ == 1) return false;
-  else              return true;
+  if (exe_ctr++ == 1) return !enabled;
+
+  return true;
 }
 
 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

src/models/FGModel.h

@@ -59,6 +59,15 @@ CLASS DOCUMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 /** Base class for all scheduled JSBSim models
+
+    Each model binds simulation/models/<Name>/enabled (default true), where Name
+    is the name passed to the constructor. Setting that property false skips the
+    model's Run(): its last state and its property bindings are preserved, which
+    is the property-tree mechanism by which an external system can replace a
+    model, for example a host physics engine owning FGGroundReactions. The
+    binding is made at construction, so a model that renames itself while
+    loading does not move its enable property.
+
     @author Jon S. Berndt
   */
 
@@ -70,14 +79,16 @@ class JSBSIM_API FGModel : public FGModelFunctions
 {
 public:
 
-  /// Constructor
-  explicit FGModel(FGFDMExec*);
+  /** Constructor.
+      @param name the name of this model. It populates the member Name and binds
+                  simulation/models/<name>/enabled. */
+  FGModel(FGFDMExec*, const std::string& name);
   /// Destructor
   ~FGModel() override;
 
   /** Runs the model; called by the Executive.
       Can pass in a value indicating if the executive is directing the simulation to Hold.
-      @param Holding if true, the executive has been directed to hold the sim from 
+      @param Holding if true, the executive has been directed to hold the sim from
                      advancing time. Some models may ignore this flag, such as the Input
                      model, which may need to be active to listen on a socket for the
                      "Resume" command to be given. The Holding flag is not used in the base
@@ -101,6 +112,7 @@ class JSBSIM_API FGModel : public FGModelFunctions
 protected:
   unsigned int exe_ctr;
   unsigned int rate;
+  bool enabled = true;
   std::string Name;
 
   /** Uploads this model in memory.

src/models/FGOutput.cpp

@@ -55,9 +55,8 @@ namespace JSBSim {
 CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-FGOutput::FGOutput(FGFDMExec* fdmex) : FGModel(fdmex)
+FGOutput::FGOutput(FGFDMExec* fdmex) : FGModel(fdmex, "FGOutput")
 {
-  Name = "FGOutput";
   enabled = true;
 
   PropertyManager->Tie<FGOutput, int>("simulation/force-output", this, nullptr,
@@ -97,7 +96,6 @@ bool FGOutput::Run(bool Holding)
   if (FDMExec->GetTrimStatus()) return true;
   if (FGModel::Run(Holding)) return true;
   if (Holding) return false;
-  if (!enabled) return true;
 
   for (auto output: OutputTypes)
     output->Run(Holding);

src/models/FGOutput.h

@@ -222,7 +222,6 @@ class JSBSIM_API FGOutput : public FGModel
 
 private:
   std::vector<FGOutputType*> OutputTypes;
-  bool enabled;
   SGPath includePath;
 
   void Debug(int from) override;

src/models/FGPropagate.cpp

@@ -81,10 +81,8 @@ CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 FGPropagate::FGPropagate(FGFDMExec* fdmex)
-  : FGModel(fdmex)
+  : FGModel(fdmex, "FGPropagate")
 {
-  Name = "FGPropagate";
-
   Inertial = FDMExec->GetInertial();
 
   /// These define the indices use to select the various integrators.

src/models/FGPropulsion.cpp

@@ -72,10 +72,8 @@ extern short debug_lvl;
 CLASS IMPLEMENTATION
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-FGPropulsion::FGPropulsion(FGFDMExec* exec) : FGModel(exec)
+FGPropulsion::FGPropulsion(FGFDMExec* exec) : FGModel(exec, "FGPropulsion")
 {
-  Name = "FGPropulsion";
-
   ActiveEngine = -1; // -1: ALL, 0: Engine 1, 1: Engine 2 ...
   tankJ.InitMatrix();
   DumpRate = 0.0;

src/models/atmosphere/FGWinds.cpp

@@ -73,10 +73,8 @@ static inline double square_signed (double value)
 constexpr double sqr(double x) { return x*x; }
 
 FGWinds::FGWinds(FGFDMExec* fdmex)
-  : FGModel(fdmex), generator(fdmex->GetRandomGenerator())
+  : FGModel(fdmex, "FGWinds"), generator(fdmex->GetRandomGenerator())
 {
-  Name = "FGWinds";
-
   MagnitudedAccelDt = MagnitudeAccel = Magnitude = TurbDirection = 0.0;
   SetTurbType( ttMilspec );
   TurbGain = 1.0;