svx: make SdrObject abstract by making CloneSdrObject pure virtual

This change makes SdrObject an abstract class that can't be as
we don't want it to be instantiated. With this the ClonseSdrObject
became a pure virtual function.

With this change also the SwFlyDrawObj needs a implementation of
the CloneSdrFunction, which was previously provided by SdrObject.

Change-Id: I2efb8c1e6fac12b17ce497285067029d7da1c1fd
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/148239
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

include/svx/svdobj.hxx

@@ -442,7 +442,7 @@ public:
     virtual bool HasLimitedRotation() const;
 
     // Returns a copy of the object. Every inherited class must reimplement this.
-    virtual rtl::Reference<SdrObject> CloneSdrObject(SdrModel& rTargetModel) const;
+    virtual rtl::Reference<SdrObject> CloneSdrObject(SdrModel& rTargetModel) const = 0;
     // helper, since Clone always return the type of the current subclass
     template<class T>
     static rtl::Reference<T> Clone(T const & rObj, SdrModel& rTargetModel)

svx/source/svdraw/svdobj.cxx

@@ -1048,11 +1048,6 @@ bool SdrObject::HasLimitedRotation() const
     return false;
 }
 
-rtl::Reference<SdrObject> SdrObject::CloneSdrObject(SdrModel& rTargetModel) const
-{
-    return new SdrObject(rTargetModel, *this);
-}
-
 OUString SdrObject::TakeObjNameSingul() const
 {
     OUString sName(SvxResId(STR_ObjNameSingulNONE));
@@ -3329,7 +3324,7 @@ rtl::Reference<SdrObject> SdrObjFactory::MakeNewObject(
                 }
             }
             break;
-            case SdrObjKind::NONE       : pObj=new SdrObject(rSdrModel);                   break;
+            case SdrObjKind::NONE       : pObj = nullptr; break;
             case SdrObjKind::Group       : pObj=new SdrObjGroup(rSdrModel);                 break;
             case SdrObjKind::Polygon       : pObj=new SdrPathObj(rSdrModel, SdrObjKind::Polygon       ); break;
             case SdrObjKind::PolyLine       : pObj=new SdrPathObj(rSdrModel, SdrObjKind::PolyLine       ); break;

sw/source/core/draw/dflyobj.cxx

@@ -130,6 +130,12 @@ SwFlyDrawObj::SwFlyDrawObj(SdrModel& rSdrModel)
 {
 }
 
+SwFlyDrawObj::SwFlyDrawObj(SdrModel& rSdrModel, SwFlyDrawObj const& rSource)
+    : SdrObject(rSdrModel, rSource)
+    , mbIsTextBox(false)
+{
+}
+
 SwFlyDrawObj::~SwFlyDrawObj()
 {
 }
@@ -145,6 +151,11 @@ SdrObjKind SwFlyDrawObj::GetObjIdentifier() const
     return SdrObjKind::SwFlyDrawObjIdentifier;
 }
 
+rtl::Reference<SdrObject> SwFlyDrawObj::CloneSdrObject(SdrModel& rTargetModel) const
+{
+    return new SwFlyDrawObj(rTargetModel);
+}
+
 // TODO: Need own primitive to get the FlyFrame paint working
 namespace drawinglayer::primitive2d
 {

sw/source/core/inc/dflyobj.hxx

@@ -44,8 +44,11 @@ private:
 
 public:
     SwFlyDrawObj(SdrModel& rSdrModel);
+    SwFlyDrawObj(SdrModel& rSdrModel, SwFlyDrawObj const& rSource);
+
+    // for instantiation of this class while loading (via factory
+    virtual rtl::Reference<SdrObject> CloneSdrObject(SdrModel& rTargetModel) const override;
 
-    // for instantiation of this class while loading (via factory)
     virtual SdrInventor GetObjInventor()     const override;
     virtual SdrObjKind GetObjIdentifier()   const override;
     virtual bool IsTextBox() const override { return mbIsTextBox; }