App: Fix const correctness

src/App/Datums.cpp

@@ -68,7 +68,7 @@ bool DatumElement::getCameraAlignmentDirection(Base::Vector3d& direction, const
     return true;
 }
 
-App::LocalCoordinateSystem* DatumElement::getLCS()
+App::LocalCoordinateSystem* DatumElement::getLCS() const
 {
     auto inList = getInList();
     for (auto* obj : inList) {
@@ -81,9 +81,9 @@ App::LocalCoordinateSystem* DatumElement::getLCS()
     return nullptr;
 }
 
-bool DatumElement::isOriginFeature()
+bool DatumElement::isOriginFeature() const
 {
-    auto lcs = getLCS();
+    const auto* lcs = getLCS();
     return lcs ? lcs->isOrigin() : false;
 }
 

src/App/Datums.h

@@ -50,14 +50,14 @@ public:
     ~DatumElement() override;
 
     /// Finds the origin object this plane belongs to
-    App::LocalCoordinateSystem* getLCS();
+    App::LocalCoordinateSystem* getLCS() const;
     Base::Vector3d getBasePoint() const;
     Base::Vector3d getDirection() const;
 
     bool getCameraAlignmentDirection(Base::Vector3d& direction, const char* subname) const override;
 
     /// Returns true if this DatumElement is part of a App::Origin.
-    bool isOriginFeature();
+    bool isOriginFeature() const;
 };
 
 class AppExport Plane: public App::DatumElement
@@ -199,7 +199,7 @@ public:
     /// Points types
     static constexpr const char* PointRoles[1] = {"Origin"};
 
-    virtual bool isOrigin()
+    virtual bool isOrigin() const
     {
         return false;
     }

src/App/Origin.h

@@ -48,10 +48,10 @@ public:
         return "Gui::ViewProviderCoordinateSystem";
     }
 
-    bool isOrigin() override
+    bool isOrigin() const override
     {
         return true;
-    };
+    }
 };
 
 }  // namespace App