Display AI traffic route in map.

Add some helpers so MapWidget can show the
origin and destination of AIAircraft with a FlightPlan.

src/AIModel/AIFlightPlan.cxx

@@ -483,3 +483,13 @@ FGParking* FGAIFlightPlan::getParkingGate()
 {
   return gate.parking();
 }
+
+FGAirportRef FGAIFlightPlan::departureAirport() const
+{
+    return departure;
+}
+
+FGAirportRef FGAIFlightPlan::arrivalAirport() const
+{
+    return arrival;
+}

src/AIModel/AIFlightPlan.hxx

@@ -168,6 +168,8 @@ public:
   void setGate(const ParkingAssignment& pka);
   FGParking* getParkingGate();
 
+    FGAirportRef departureAirport() const;
+    FGAirportRef arrivalAirport() const;
 private:
   FGAIFlightPlan *sid;
   typedef std::vector <FGAIWaypoint*> wpt_vector_type;

src/AIModel/AIManager.cxx

@@ -287,7 +287,7 @@ FGAIManager::attach(FGAIBase *model)
 }
 
 int
-FGAIManager::getNumAiObjects(void) const
+FGAIManager::getNumAiObjects() const
 {
     return ai_list.size();
 }
@@ -405,6 +405,17 @@ bool FGAIManager::removeObject(const SGPropertyNode* args)
     return false;
 }
 
+FGAIBasePtr FGAIManager::getObjectFromProperty(const SGPropertyNode* aProp) const
+{
+    BOOST_FOREACH(FGAIBase* ai, get_ai_list()) {
+        if (ai->_getProps() == aProp) {
+            return ai;
+        }
+    } // of AI objects iteration
+    
+    return NULL;
+}
+
 bool
 FGAIManager::loadScenario( const string &filename )
 {

src/AIModel/AIManager.hxx

@@ -46,16 +46,6 @@ class FGAIManager : public SGSubsystem
 {
 
 public:
-
-    // A list of pointers to AI objects
-    typedef std::list <FGAIBasePtr> ai_list_type;
-    typedef ai_list_type::iterator ai_list_iterator;
-    typedef ai_list_type::const_iterator ai_list_const_iterator;
-
-    const ai_list_type& get_ai_list() const {
-        return ai_list;
-    }
-
     FGAIManager();
     virtual ~FGAIManager();
 
@@ -79,8 +69,6 @@ public:
     inline double get_user_roll() const { return user_roll; }
     inline double get_user_agl() const { return user_altitude_agl; }
 
-    int getNumAiObjects(void) const;
-
     bool loadScenario( const std::string &filename );
 
     static SGPropertyNode_ptr loadScenarioFile(const std::string& filename);
@@ -90,7 +78,26 @@ public:
 
     FGAIBasePtr addObject(const SGPropertyNode* definition);
     
+    /**
+     * @brief given a reference to an /ai/models/<foo>[n] node, return the
+     * corresponding AIObject implementation, or NULL.
+     */
+    FGAIBasePtr getObjectFromProperty(const SGPropertyNode* aProp) const;
 private:
+    // FGSubmodelMgr is a friend for access to the AI_list
+    friend class FGSubmodelMgr;
+    
+    // A list of pointers to AI objects
+    typedef std::list <FGAIBasePtr> ai_list_type;
+    typedef ai_list_type::iterator ai_list_iterator;
+    typedef ai_list_type::const_iterator ai_list_const_iterator;
+    
+    const ai_list_type& get_ai_list() const {
+        return ai_list;
+    }
+
+    int getNumAiObjects() const;
+    
     void removeDeadItem(FGAIBase* base);
   
     double calcRangeFt(const SGVec3d& aCartPos, FGAIBase* aObject) const;

src/GUI/MapWidget.cxx

@@ -26,6 +26,8 @@
 #include <Main/fg_os.hxx>      // fgGetKeyModifiers()
 #include <Navaids/routePath.hxx>
 #include <Aircraft/FlightHistory.hxx>
+#include <AIModel/AIAircraft.hxx>
+#include <AIModel/AIFlightPlan.hxx>
 
 const char* RULER_LEGEND_KEY = "ruler-legend";
 
@@ -1561,22 +1563,38 @@ void MapWidget::drawAIAircraft(const SGPropertyNode* model, const SGGeod& pos, d
 
     drawLine(p, project(advance));
   }
-
+   
+    // try to access the flight-plan of the aircraft. There are several layers
+    // of potential NULL-ness here, so we have to be defensive at each stage.
+    std::string originICAO, destinationICAO;
+    FGAIManager* aiManager = static_cast<FGAIManager*>(globals->get_subsystem("ai-model"));
+    FGAIBasePtr aircraft = aiManager ? aiManager->getObjectFromProperty(model) : NULL;
+    if (aircraft) {
+        FGAIAircraft* p = static_cast<FGAIAircraft*>(aircraft.get());
+        if (p->GetFlightPlan()) {
+            originICAO = p->GetFlightPlan()->departureAirport()->ident();
+            destinationICAO = p->GetFlightPlan()->arrivalAirport()->ident();
+        }
+    }
 
   // draw callsign / altitude / speed
-  char buffer[1024];
-	::snprintf(buffer, 1024, "%s\n%d'\n%dkts",
-		model->getStringValue("callsign", "<>"),
-		static_cast<int>(pos.getElevationFt() / 50.0) * 50,
-    speedKts);
-
-  MapData* d = getOrCreateDataForKey((void*) model);
-  d->setText(buffer);
-  d->setLabel(model->getStringValue("callsign", "<>"));
-  d->setPriority(speedKts > 5 ? 60 : 10); // low priority for parked aircraft
-  d->setOffset(MapData::VALIGN_CENTER | MapData::HALIGN_LEFT, 10);
-  d->setAnchor(p);
-
+    int altFt50 = static_cast<int>(pos.getElevationFt() / 50.0) * 50;
+    std::ostringstream ss;
+    ss << model->getStringValue("callsign", "<>");
+    if (speedKts > 1) {
+        ss << "\n" << altFt50 << "' " << speedKts << "kts";
+    }
+    
+    if (!originICAO.empty() || ! destinationICAO.empty()) {
+        ss << "\n" << originICAO << " -> " << destinationICAO;
+    }
+    
+    MapData* d = getOrCreateDataForKey((void*) model);
+    d->setText(ss.str().c_str());
+    d->setLabel(model->getStringValue("callsign", "<>"));
+    d->setPriority(speedKts > 5 ? 60 : 10); // low priority for parked aircraft
+    d->setOffset(MapData::VALIGN_CENTER | MapData::HALIGN_LEFT, 10);
+    d->setAnchor(p);
 }
 
 void MapWidget::drawAIShip(const SGPropertyNode* model, const SGGeod& pos, double hdg)