Ref T242, null functions for livery, airline, aircraft

src/blackmisc/aviation/aircrafticaocode.cpp

@@ -196,6 +196,17 @@ namespace BlackMisc
             return score;
         }
 
+        bool CAircraftIcaoCode::isNull() const
+        {
+            return m_designator.isEmpty() && m_manufacturer.isEmpty() && m_modelDescription.isEmpty();
+        }
+
+        const CAircraftIcaoCode &CAircraftIcaoCode::null()
+        {
+            static const CAircraftIcaoCode null;
+            return null;
+        }
+
         bool CAircraftIcaoCode::hasDesignator() const
         {
             return !m_designator.isEmpty();

src/blackmisc/aviation/aircrafticaocode.h

@@ -291,6 +291,12 @@ namespace BlackMisc
             //! \remark normally used with a selected set of ICAO codes or combined types
             int calculateScore(const CAircraftIcaoCode &otherCode, CStatusMessageList *log = nullptr) const;
 
+            //! Null ICAO?
+            bool isNull() const;
+
+            //! NULL object
+            static const CAircraftIcaoCode &null();
+
             //! Valid designator?
             static bool isValidDesignator(const QString &designator);
 

src/blackmisc/aviation/airlineicaocode.cpp

@@ -410,6 +410,17 @@ namespace BlackMisc
             return score;
         }
 
+        bool CAirlineIcaoCode::isNull() const
+        {
+            return m_designator.isNull() && m_iataCode.isNull() && m_telephonyDesignator.isNull();
+        }
+
+        const CAirlineIcaoCode &CAirlineIcaoCode::null()
+        {
+            static const CAirlineIcaoCode null;
+            return null;
+        }
+
         CAirlineIcaoCode CAirlineIcaoCode::fromDatabaseJson(const QJsonObject &json, const QString &prefix)
         {
             if (!existsKey(json, prefix))

src/blackmisc/aviation/airlineicaocode.h

@@ -228,6 +228,12 @@ namespace BlackMisc
             //! Score against other code 0..100
             int calculateScore(const CAirlineIcaoCode &otherCode, CStatusMessageList *log = nullptr) const;
 
+            //! Null ICAO?
+            bool isNull() const;
+
+            //! NULL object
+            static const CAirlineIcaoCode &null();
+
             //! Valid designator?
             static bool isValidAirlineDesignator(const QString &airline);
 

src/blackmisc/aviation/livery.cpp

@@ -423,5 +423,16 @@ namespace BlackMisc
             }
             return score;
         }
+
+        bool CLivery::isNull() const
+        {
+            return m_airline.isNull() && m_combinedCode.isEmpty() && m_description.isEmpty();
+        }
+
+        const CLivery &CLivery::null()
+        {
+            static const CLivery null;
+            return null;
+        }
     } // namespace
 } // namespace

src/blackmisc/aviation/livery.h

@@ -180,6 +180,12 @@ namespace BlackMisc
             //! \remark normally used with liveries preselect by airline ICAO code
             int calculateScore(const CLivery &otherLivery, bool preferColorLiveries = false, CStatusMessageList *log = nullptr) const;
 
+            //! Null livery?
+            bool isNull() const;
+
+            //! NULL object
+            static const CLivery &null();
+
             //! Object from JSON
             static CLivery fromDatabaseJson(const QJsonObject &json, const QString &prefix = QString("liv_"));