Ref T260, utility functions to set provider, plane ctor

src/blackmisc/geo/elevationplane.cpp

@@ -34,6 +34,10 @@ namespace BlackMisc
             m_radius = this->calculateGreatCircleDistance(rangeCoordinate);
         }
 
+        CElevationPlane::CElevationPlane(const ICoordinateGeodetic &coordinate, const CLength &radius) :
+            CCoordinateGeodetic(coordinate), m_radius(radius)
+        { }
+
         const CAltitude &CElevationPlane::getAltitudeIfWithinRadius(const ICoordinateGeodetic &coordinate) const
         {
             return (isWithinRange(coordinate)) ? geodeticHeight() : CAltitude::null();

src/blackmisc/geo/elevationplane.h

@@ -36,6 +36,9 @@ namespace BlackMisc
             //! Plane at given coordinates with range to 2nd coordinate
             CElevationPlane(const ICoordinateGeodetic &coordinate, const ICoordinateGeodetic &rangeCoordinate);
 
+            //! Plane at given coordinates with radius
+            CElevationPlane(const ICoordinateGeodetic &coordinate, const PhysicalQuantities::CLength &radius);
+
             //! Constructors from CCoordinateGeodetic
             using CCoordinateGeodetic::CCoordinateGeodetic;
 

src/blackmisc/provider.h

@@ -44,6 +44,7 @@ namespace BlackMisc
         //! \remark use individual names to disambiguate
         void setProvider(PROVIDER *provider)
         {
+            if (m_provider == provider) { return; }
             if (m_provider) { m_lastProviderConnections.disconnectAll(); }
             m_provider = provider; // new provider
             IProvider *iProvider = dynamic_cast<IProvider *>(provider);