diff --git a/src/App/FreeCADInit.py b/src/App/FreeCADInit.py
index 6d9a10722c..be22a7d83b 100644
--- a/src/App/FreeCADInit.py
+++ b/src/App/FreeCADInit.py
@@ -892,10 +892,7 @@ App.Units.KinematicViscosity           = App.Units.Unit(2,0,-1)
 App.Units.VacuumPermittivity           = App.Units.Unit(-3,-1,4,2)
 
 # Add an enum for the different unit schemes
-if sys.version_info.major < 3:
-    IntEnum = object
-else:
-    from enum import IntEnum
+from enum import IntEnum
 
 # The values must match with that of the
 # C++ enum class UnitSystem
diff --git a/src/Gui/ActiveObjectList.cpp b/src/Gui/ActiveObjectList.cpp
index a31878cd96..ef5e6720a4 100644
--- a/src/Gui/ActiveObjectList.cpp
+++ b/src/Gui/ActiveObjectList.cpp
@@ -90,7 +90,7 @@ Gui::ActiveObjectList::ObjectInfo Gui::ActiveObjectList::getObjectInfo(App::Docu
         // If the input object is not from this document, it must be brought in
         // by some link type object of this document. We only accept the object
         // if we can find such object in the current selection.
-        auto sels = Gui::Selection().getSelection(_Doc->getDocument()->getName(),false);
+        auto sels = Gui::Selection().getSelection(_Doc->getDocument()->getName(), ResolveMode::NoResolve);
         for (auto &sel : sels) {
             if (sel.pObject == obj || sel.pObject->getLinkedObject(true)==obj) {
                 info.obj = sel.pObject;
diff --git a/src/Gui/CommandFeat.cpp b/src/Gui/CommandFeat.cpp
index 33c00319db..25e8648ea3 100644
--- a/src/Gui/CommandFeat.cpp
+++ b/src/Gui/CommandFeat.cpp
@@ -144,7 +144,8 @@ bool StdCmdSendToPythonConsole::isActive(void)
 void StdCmdSendToPythonConsole::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
-    const std::vector<Gui::SelectionObject> &sels = Gui::Selection().getSelectionEx("*",App::DocumentObject::getClassTypeId(),true,false);
+    const std::vector<Gui::SelectionObject> &sels = Gui::Selection().getSelectionEx("*", App::DocumentObject::getClassTypeId(),
+                                                                                    ResolveMode::OldStyleElement, false);
     if (sels.empty())
         return;
     const App::DocumentObject *obj = sels[0].getObject();
diff --git a/src/Gui/CommandLink.cpp b/src/Gui/CommandLink.cpp
index 34fb044168..5f57626de1 100644
--- a/src/Gui/CommandLink.cpp
+++ b/src/Gui/CommandLink.cpp
@@ -290,7 +290,7 @@ void StdCmdLinkMakeRelative::activated(int) {
     try {
         std::map<std::pair<App::DocumentObject*,std::string>,
                  std::pair<App::DocumentObject*, std::vector<std::string> > > linkInfo;
-        for(auto &sel : Selection().getCompleteSelection(0)) {
+        for(auto &sel : Selection().getCompleteSelection(ResolveMode::NoResolve)) {
             if(!sel.pObject || !sel.pObject->getNameInDocument())
                 continue;
             auto key = std::make_pair(sel.pObject,
@@ -548,7 +548,7 @@ StdCmdLinkImport::StdCmdLinkImport()
 static std::map<App::Document*, std::vector<App::DocumentObject*> > getLinkImportSelections()
 {
     std::map<App::Document*, std::vector<App::DocumentObject*> > objMap;
-    for(auto &sel : Selection().getCompleteSelection(false)) {
+    for(auto &sel : Selection().getCompleteSelection(ResolveMode::NoResolve)) {
         auto obj = sel.pObject->resolve(sel.SubName);
         if(!obj || !obj->getNameInDocument())
             continue;
@@ -652,7 +652,7 @@ StdCmdLinkSelectLinked::StdCmdLinkSelectLinked()
 }
 
 static App::DocumentObject *getSelectedLink(bool finalLink, std::string *subname=nullptr) {
-    const auto &sels = Selection().getSelection("*",0,true);
+    const auto &sels = Selection().getSelection("*", ResolveMode::NoResolve, true);
     if(sels.empty())
         return nullptr;
     auto sobj = sels[0].pObject->getSubObject(sels[0].SubName);
@@ -812,7 +812,7 @@ StdCmdLinkSelectAllLinks::StdCmdLinkSelectAllLinks()
 }
 
 bool StdCmdLinkSelectAllLinks::isActive() {
-    const auto &sels = Selection().getSelection("*",true,true);
+    const auto &sels = Selection().getSelection("*", ResolveMode::OldStyleElement, true);
     if(sels.empty())
         return false;
     return App::GetApplication().hasLinksTo(sels[0].pObject);
@@ -820,7 +820,7 @@ bool StdCmdLinkSelectAllLinks::isActive() {
 
 void StdCmdLinkSelectAllLinks::activated(int)
 {
-    auto sels = Selection().getSelection("*",true,true);
+    auto sels = Selection().getSelection("*", ResolveMode::OldStyleElement, true);
     if(sels.empty())
         return;
     Selection().selStackPush();
diff --git a/src/Gui/CommandView.cpp b/src/Gui/CommandView.cpp
index 59114f5828..a6fc994650 100644
--- a/src/Gui/CommandView.cpp
+++ b/src/Gui/CommandView.cpp
@@ -458,7 +458,7 @@ void StdCmdFreezeViews::onRestoreViews()
 
     bool ok;
     int scheme = root.attribute(QString::fromLatin1("SchemaVersion")).toInt(&ok);
-    if (!ok)
+    if (!ok)
         return;
     // SchemeVersion "1"
     if (scheme == 1) {
@@ -1695,7 +1695,7 @@ void StdViewDockUndockFullscreen::activated(int iMsg)
 
     MDIView* view = getMainWindow()->activeWindow();
     if (!view) // no active view
-        return;
+        return;
 
     // nothing to do when the view is docked and 'Docked' is pressed
     if (iMsg == 0 && view->currentViewMode() == MDIView::Child)
@@ -2169,7 +2169,7 @@ bool StdCmdAxisCross::isActive(void)
         if (_pcAction->isChecked())
             _pcAction->setChecked(false);
     }
-    if (view )
+    if (view)
         return true;
     return false;
 
@@ -3125,7 +3125,7 @@ StdCmdTreeSelectAllInstances::StdCmdTreeSelectAllInstances()
 
 bool StdCmdTreeSelectAllInstances::isActive(void)
 {
-    const auto &sels = Selection().getSelectionEx("*",App::DocumentObject::getClassTypeId(),true,true);
+    const auto &sels = Selection().getSelectionEx("*",App::DocumentObject::getClassTypeId(), ResolveMode::OldStyleElement, true);
     if(sels.empty())
         return false;
     auto obj = sels[0].getObject();
@@ -3138,7 +3138,7 @@ bool StdCmdTreeSelectAllInstances::isActive(void)
 void StdCmdTreeSelectAllInstances::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
-    const auto &sels = Selection().getSelectionEx("*",App::DocumentObject::getClassTypeId(),true,true);
+    const auto &sels = Selection().getSelectionEx("*",App::DocumentObject::getClassTypeId(), ResolveMode::OldStyleElement, true);
     if(sels.empty())
         return;
     auto obj = sels[0].getObject();
diff --git a/src/Gui/DlgPropertyLink.cpp b/src/Gui/DlgPropertyLink.cpp
index 8036235892..4d72d36da0 100644
--- a/src/Gui/DlgPropertyLink.cpp
+++ b/src/Gui/DlgPropertyLink.cpp
@@ -66,7 +66,7 @@ public:
 /* TRANSLATOR Gui::Dialog::DlgPropertyLink */
 
 DlgPropertyLink::DlgPropertyLink(QWidget* parent)
-  : QDialog(parent), SelectionObserver(false,0)
+  : QDialog(parent), SelectionObserver(false, ResolveMode::NoResolve)
   , ui(new Ui_DlgPropertyLink)
 {
     ui->setupUi(this);
@@ -428,7 +428,7 @@ void DlgPropertyLink::attachObserver() {
             auto view = qobject_cast<Gui::PropertyView*>(p);
             if(view) {
                 parentView = view;
-                for(auto &sel : Gui::Selection().getCompleteSelection(0))
+                for(auto &sel : Gui::Selection().getCompleteSelection(ResolveMode::NoResolve))
                     savedSelections.emplace_back(sel.DocName, sel.FeatName, sel.SubName);
                 break;
             }
diff --git a/src/Gui/Document.cpp b/src/Gui/Document.cpp
index 6cbb1e82ac..8534420820 100644
--- a/src/Gui/Document.cpp
+++ b/src/Gui/Document.cpp
@@ -297,7 +297,7 @@ bool Document::setEdit(Gui::ViewProvider* p, int ModNum, const char *subname)
     if(!subname || !subname[0]) {
         // No subname reference is given, we try to extract one from the current
         // selection in order to obtain the correct transformation matrix below
-        auto sels = Gui::Selection().getCompleteSelection(false);
+        auto sels = Gui::Selection().getCompleteSelection(ResolveMode::NoResolve);
         App::DocumentObject *parentObj = nullptr;
         for(auto &sel : sels) {
             if(!sel.pObject || !sel.pObject->getNameInDocument())
@@ -737,7 +737,7 @@ void Document::slotDeletedObject(const App::DocumentObject& Obj)
 
     // cycling to all views of the document
     ViewProvider* viewProvider = getViewProvider(&Obj);
-    if(!viewProvider)
+    if(!viewProvider)
         return;
 
     if (d->_editViewProvider==viewProvider || d->_editViewProviderParent==viewProvider)
diff --git a/src/Gui/PropertyView.cpp b/src/Gui/PropertyView.cpp
index 3fcc88fc09..5426716f58 100644
--- a/src/Gui/PropertyView.cpp
+++ b/src/Gui/PropertyView.cpp
@@ -66,7 +66,7 @@ static ParameterGrp::handle _GetParam() {
  * in two tabs.
  */
 PropertyView::PropertyView(QWidget *parent)
-  : QWidget(parent), SelectionObserver(false, 0)
+  : QWidget(parent), SelectionObserver(false, ResolveMode::NoResolve)
 {
     QGridLayout* pLayout = new QGridLayout( this );
     pLayout->setSpacing(0);
@@ -298,7 +298,7 @@ void PropertyView::checkEnable(const char *doc) {
     }
     // check if at least one selected object is part of the active document
     setEnabled(!Selection().hasSelection()
-            || Selection().hasSelection(doc,false));
+            || Selection().hasSelection(doc, ResolveMode::NoResolve));
 }
 
 struct PropertyView::PropInfo
diff --git a/src/Gui/Selection.cpp b/src/Gui/Selection.cpp
index 92a872fa0c..cedfbb257e 100644
--- a/src/Gui/Selection.cpp
+++ b/src/Gui/Selection.cpp
@@ -79,7 +79,7 @@ bool SelectionGateFilterExternal::allow(App::Document *doc ,App::DocumentObject
 
 //////////////////////////////////////////////////////////////////////////////////////////
 
-SelectionObserver::SelectionObserver(bool attach, int resolve)
+SelectionObserver::SelectionObserver(bool attach, ResolveMode resolve)
     : resolve(resolve)
     , blockedSelection(false)
 {
@@ -87,7 +87,7 @@ SelectionObserver::SelectionObserver(bool attach, int resolve)
         attachSelection();
 }
 
-SelectionObserver::SelectionObserver(const ViewProviderDocumentObject *vp,bool attach, int resolve)
+SelectionObserver::SelectionObserver(const ViewProviderDocumentObject *vp, bool attach, ResolveMode resolve)
     : resolve(resolve)
     , blockedSelection(false)
 {
@@ -125,9 +125,11 @@ bool SelectionObserver::isSelectionAttached() const
 void SelectionObserver::attachSelection()
 {
     if (!connectSelection.connected()) {
-        auto &signal = resolve > 1 ? Selection().signalSelectionChanged3 :
-                       resolve     ? Selection().signalSelectionChanged2 :
-                                     Selection().signalSelectionChanged  ;
+        bool newStyle = (resolve >= ResolveMode::NewStyleElement);
+        bool oldStyle = (resolve == ResolveMode::OldStyleElement);
+        auto &signal = newStyle ? Selection().signalSelectionChanged3 :
+                       oldStyle ? Selection().signalSelectionChanged2 :
+                                  Selection().signalSelectionChanged  ;
         connectSelection = signal.connect(boost::bind
             (&SelectionObserver::_onSelectionChanged, this, bp::_1));
 
@@ -166,8 +168,8 @@ void SelectionObserver::detachSelection()
 
 std::vector<SelectionObserverPython*> SelectionObserverPython::_instances;
 
-SelectionObserverPython::SelectionObserverPython(const Py::Object& obj, int resolve)
-    : SelectionObserver(true,resolve),inst(obj)
+SelectionObserverPython::SelectionObserverPython(const Py::Object& obj, ResolveMode resolve)
+    : SelectionObserver(true, resolve), inst(obj)
 {
 #undef FC_PY_ELEMENT
 #define FC_PY_ELEMENT(_name) FC_PY_GetCallable(obj.ptr(),#_name,py_##_name);
@@ -178,9 +180,9 @@ SelectionObserverPython::~SelectionObserverPython()
 {
 }
 
-void SelectionObserverPython::addObserver(const Py::Object& obj, int resolve)
+void SelectionObserverPython::addObserver(const Py::Object& obj, ResolveMode resolve)
 {
-    _instances.push_back(new SelectionObserverPython(obj,resolve));
+    _instances.push_back(new SelectionObserverPython(obj, resolve));
 }
 
 void SelectionObserverPython::removeObserver(const Py::Object& obj)
@@ -362,20 +364,20 @@ bool SelectionSingleton::hasPreselection() const {
     return !CurrentPreselection.Object.getObjectName().empty();
 }
 
-std::vector<SelectionSingleton::SelObj> SelectionSingleton::getCompleteSelection(int resolve) const
+std::vector<SelectionSingleton::SelObj> SelectionSingleton::getCompleteSelection(ResolveMode resolve) const
 {
-    return getSelection("*",resolve);
+    return getSelection("*", resolve);
 }
 
-std::vector<SelectionSingleton::SelObj> SelectionSingleton::getSelection(const char* pDocName,
-        int resolve, bool single) const
+std::vector<SelectionSingleton::SelObj> SelectionSingleton::getSelection(const char* pDocName, ResolveMode resolve, bool single) const
 {
     std::vector<SelObj> temp;
-    if(single) temp.reserve(1);
+    if (single)
+        temp.reserve(1);
     SelObj tempSelObj;
 
     App::Document *pcDoc = nullptr;
-    if(!pDocName || strcmp(pDocName,"*")!=0) {
+    if(!pDocName || strcmp(pDocName,"*") != 0) {
         pcDoc = getDocument(pDocName);
         if (!pcDoc)
             return temp;
@@ -384,17 +386,18 @@ std::vector<SelectionSingleton::SelObj> SelectionSingleton::getSelection(const c
     std::map<App::DocumentObject*,std::set<std::string> > objMap;
 
     for(auto &sel : _SelList) {
-        if(!sel.pDoc) continue;
+        if (!sel.pDoc)
+            continue;
         const char *subelement = nullptr;
-        auto obj = getObjectOfType(sel,App::DocumentObject::getClassTypeId(),resolve,&subelement);
-        if(!obj || (pcDoc && sel.pObject->getDocument()!=pcDoc))
+        auto obj = getObjectOfType(sel, App::DocumentObject::getClassTypeId(), resolve, &subelement);
+        if (!obj || (pcDoc && sel.pObject->getDocument() != pcDoc))
             continue;
 
         // In case we are resolving objects, make sure no duplicates
-        if(resolve && !objMap[obj].insert(std::string(subelement?subelement:"")).second)
+        if (resolve != ResolveMode::NoResolve && !objMap[obj].insert(std::string(subelement ? subelement : "")).second)
             continue;
 
-        if(single && temp.size()) {
+        if (single && temp.size()) {
             temp.clear();
             break;
         }
@@ -416,18 +419,19 @@ std::vector<SelectionSingleton::SelObj> SelectionSingleton::getSelection(const c
     return temp;
 }
 
-bool SelectionSingleton::hasSelection(const char* doc, bool resolve) const
+bool SelectionSingleton::hasSelection(const char* doc, ResolveMode resolve) const
 {
     App::Document *pcDoc = nullptr;
-    if(!doc || strcmp(doc,"*")!=0) {
+    if (!doc || strcmp(doc,"*") != 0) {
         pcDoc = getDocument(doc);
         if (!pcDoc)
             return false;
     }
     for(auto &sel : _SelList) {
-        if(!sel.pDoc) continue;
-        auto obj = getObjectOfType(sel,App::DocumentObject::getClassTypeId(),resolve);
-        if(obj && (!pcDoc || sel.pObject->getDocument()==pcDoc)) {
+        if (!sel.pDoc)
+            continue;
+        auto obj = getObjectOfType(sel, App::DocumentObject::getClassTypeId(), resolve);
+        if (obj && (!pcDoc || sel.pObject->getDocument()==pcDoc)) {
             return true;
         }
     }
@@ -463,7 +467,7 @@ std::vector<SelectionSingleton::SelObj> SelectionSingleton::getPickedList(const
     SelObj tempSelObj;
 
     App::Document *pcDoc = nullptr;
-    if(!pDocName || strcmp(pDocName,"*")!=0) {
+    if(!pDocName || strcmp(pDocName,"*") != 0) {
         pcDoc = getDocument(pDocName);
         if (!pcDoc)
             return temp;
@@ -488,20 +492,24 @@ std::vector<SelectionSingleton::SelObj> SelectionSingleton::getPickedList(const
     return temp;
 }
 
-std::vector<SelectionObject> SelectionSingleton::getSelectionEx(
-        const char* pDocName, Base::Type typeId, int resolve, bool single) const {
-    return getObjectList(pDocName,typeId,_SelList,resolve,single);
+std::vector<SelectionObject> SelectionSingleton::getSelectionEx(const char* pDocName, Base::Type typeId,
+                                                                ResolveMode resolve, bool single) const
+{
+    return getObjectList(pDocName, typeId, _SelList, resolve, single);
 }
 
-std::vector<SelectionObject> SelectionSingleton::getPickedListEx(const char* pDocName, Base::Type typeId) const {
-    return getObjectList(pDocName,typeId,_PickedList,false);
+std::vector<SelectionObject> SelectionSingleton::getPickedListEx(const char* pDocName, Base::Type typeId) const
+{
+    return getObjectList(pDocName, typeId, _PickedList, ResolveMode::NoResolve);
 }
 
 std::vector<SelectionObject> SelectionSingleton::getObjectList(const char* pDocName, Base::Type typeId,
-        std::list<_SelObj> &objList, int resolve, bool single) const
+                                                               std::list<_SelObj> &objList,
+                                                               ResolveMode resolve, bool single) const
 {
     std::vector<SelectionObject> temp;
-    if(single) temp.reserve(1);
+    if (single)
+        temp.reserve(1);
     std::map<App::DocumentObject*,size_t> SortMap;
 
     // check the type
@@ -509,30 +517,31 @@ std::vector<SelectionObject> SelectionSingleton::getObjectList(const char* pDocN
         return temp;
 
     App::Document *pcDoc = nullptr;
-    if(!pDocName || strcmp(pDocName,"*")!=0) {
+    if (!pDocName || strcmp(pDocName,"*") != 0) {
         pcDoc = getDocument(pDocName);
         if (!pcDoc)
             return temp;
     }
 
     for (auto &sel : objList) {
-        if(!sel.pDoc) continue;
+        if(!sel.pDoc)
+            continue;
         const char *subelement = nullptr;
         auto obj = getObjectOfType(sel,typeId,resolve,&subelement);
-        if(!obj || (pcDoc && sel.pObject->getDocument()!=pcDoc))
+        if (!obj || (pcDoc && sel.pObject->getDocument() != pcDoc))
             continue;
         auto it = SortMap.find(obj);
         if(it!=SortMap.end()) {
             // only add sub-element
             if (subelement && *subelement) {
-                if(resolve && !temp[it->second]._SubNameSet.insert(subelement).second)
+                if (resolve != ResolveMode::NoResolve && !temp[it->second]._SubNameSet.insert(subelement).second)
                     continue;
                 temp[it->second].SubNames.push_back(subelement);
                 temp[it->second].SelPoses.emplace_back(sel.x,sel.y,sel.z);
             }
         }
         else {
-            if(single && temp.size()) {
+            if (single && temp.size()) {
                 temp.clear();
                 break;
             }
@@ -541,7 +550,7 @@ std::vector<SelectionObject> SelectionSingleton::getObjectList(const char* pDocN
             if (subelement && *subelement) {
                 temp.back().SubNames.push_back(subelement);
                 temp.back().SelPoses.emplace_back(sel.x,sel.y,sel.z);
-                if(resolve)
+                if (resolve != ResolveMode::NoResolve)
                     temp.back()._SubNameSet.insert(subelement);
             }
             SortMap.insert(std::make_pair(obj,temp.size()-1));
@@ -551,11 +560,13 @@ std::vector<SelectionObject> SelectionSingleton::getObjectList(const char* pDocN
     return temp;
 }
 
-bool SelectionSingleton::needPickedList() const {
+bool SelectionSingleton::needPickedList() const
+{
     return _needPickedList;
 }
 
-void SelectionSingleton::enablePickedList(bool enable) {
+void SelectionSingleton::enablePickedList(bool enable)
+{
     if(enable != _needPickedList) {
         _needPickedList = enable;
         _PickedList.clear();
@@ -563,7 +574,8 @@ void SelectionSingleton::enablePickedList(bool enable) {
     }
 }
 
-void SelectionSingleton::notify(SelectionChanges &&Chng) {
+void SelectionSingleton::notify(SelectionChanges &&Chng)
+{
     if(Notifying) {
         NotificationQueue.push_back(std::move(Chng));
         return;
@@ -575,10 +587,10 @@ void SelectionSingleton::notify(SelectionChanges &&Chng) {
         bool notify;
         switch(msg.Type) {
         case SelectionChanges::AddSelection:
-            notify = isSelected(msg.pDocName,msg.pObjectName,msg.pSubName,0);
+            notify = isSelected(msg.pDocName, msg.pObjectName, msg.pSubName, ResolveMode::NoResolve);
             break;
         case SelectionChanges::RmvSelection:
-            notify = !isSelected(msg.pDocName,msg.pObjectName,msg.pSubName,0);
+            notify = !isSelected(msg.pDocName, msg.pObjectName, msg.pSubName, ResolveMode::NoResolve);
             break;
         case SelectionChanges::SetPreselect:
             notify = CurrentPreselection.Type==SelectionChanges::SetPreselect
@@ -604,23 +616,27 @@ void SelectionSingleton::notify(SelectionChanges &&Chng) {
     }
 }
 
-bool SelectionSingleton::hasPickedList() const {
+bool SelectionSingleton::hasPickedList() const
+{
     return _PickedList.size();
 }
 
 int SelectionSingleton::getAsPropertyLinkSubList(App::PropertyLinkSubList &prop) const
 {
     std::vector<Gui::SelectionObject> sel = this->getSelectionEx();
-    std::vector<App::DocumentObject*> objs; objs.reserve(sel.size()*2);
+    std::vector<App::DocumentObject*> objs; objs.reserve(sel.size() * 2);
     std::vector<std::string> subs; subs.reserve(sel.size()*2);
     for (std::size_t iobj = 0; iobj < sel.size(); iobj++) {
         Gui::SelectionObject &selitem = sel[iobj];
         App::DocumentObject* obj = selitem.getObject();
         const std::vector<std::string> &subnames = selitem.getSubNames();
-        if (subnames.size() == 0){//whole object is selected
+
+        //whole object is selected
+        if (subnames.size() == 0){
             objs.push_back(obj);
             subs.emplace_back();
-        } else {
+        }
+        else {
             for (std::size_t isub = 0; isub < subnames.size(); isub++) {
                 objs.push_back(obj);
                 subs.push_back(subnames[isub]);
@@ -632,35 +648,39 @@ int SelectionSingleton::getAsPropertyLinkSubList(App::PropertyLinkSubList &prop)
     return objs.size();
 }
 
-App::DocumentObject *SelectionSingleton::getObjectOfType(_SelObj &sel,
-        Base::Type typeId, int resolve, const char **subelement)
+App::DocumentObject *SelectionSingleton::getObjectOfType(_SelObj &sel, Base::Type typeId,
+                                                         ResolveMode resolve, const char **subelement)
 {
     auto obj = sel.pObject;
     if(!obj || !obj->getNameInDocument())
         return nullptr;
     const char *subname = sel.SubName.c_str();
-    if(resolve) {
+    if (resolve != ResolveMode::NoResolve) {
         obj = sel.pResolvedObject;
-        if(resolve==2 && sel.elementName.first.size())
+        if (resolve == ResolveMode::NewStyleElement && sel.elementName.first.size())
             subname = sel.elementName.first.c_str();
         else
             subname = sel.elementName.second.c_str();
     }
-    if(!obj)
+
+    if (!obj)
         return nullptr;
-    if(!obj->isDerivedFrom(typeId) &&
-       (resolve!=3 || !obj->getLinkedObject(true)->isDerivedFrom(typeId)))
+
+    if (!obj->isDerivedFrom(typeId) && (resolve != ResolveMode::FollowLink || !obj->getLinkedObject(true)->isDerivedFrom(typeId)))
         return nullptr;
-    if(subelement) *subelement = subname;
+
+    if (subelement)
+        *subelement = subname;
+
     return obj;
 }
 
-vector<App::DocumentObject*> SelectionSingleton::getObjectsOfType(const Base::Type& typeId, const char* pDocName, int resolve) const
+vector<App::DocumentObject*> SelectionSingleton::getObjectsOfType(const Base::Type& typeId, const char* pDocName, ResolveMode resolve) const
 {
     std::vector<App::DocumentObject*> temp;
 
     App::Document *pcDoc = nullptr;
-    if(!pDocName || strcmp(pDocName,"*")!=0) {
+    if (!pDocName || strcmp(pDocName,"*") != 0) {
         pcDoc = getDocument(pDocName);
         if (!pcDoc)
             return temp;
@@ -669,7 +689,7 @@ vector<App::DocumentObject*> SelectionSingleton::getObjectsOfType(const Base::Ty
     std::set<App::DocumentObject*> objs;
     for(auto &sel : _SelList) {
         if(pcDoc && pcDoc!=sel.pDoc) continue;
-        App::DocumentObject *pObject = getObjectOfType(sel,typeId,resolve);
+        App::DocumentObject *pObject = getObjectOfType(sel, typeId, resolve);
         if (pObject) {
             auto ret = objs.insert(pObject);
             if(ret.second)
@@ -680,7 +700,7 @@ vector<App::DocumentObject*> SelectionSingleton::getObjectsOfType(const Base::Ty
     return temp;
 }
 
-std::vector<App::DocumentObject*> SelectionSingleton::getObjectsOfType(const char* typeName, const char* pDocName, int resolve) const
+std::vector<App::DocumentObject*> SelectionSingleton::getObjectsOfType(const char* typeName, const char* pDocName, ResolveMode resolve) const
 {
     Base::Type typeId = Base::Type::fromName(typeName);
     if (typeId == Base::Type::badType())
@@ -688,25 +708,25 @@ std::vector<App::DocumentObject*> SelectionSingleton::getObjectsOfType(const cha
     return getObjectsOfType(typeId, pDocName, resolve);
 }
 
-unsigned int SelectionSingleton::countObjectsOfType(const Base::Type& typeId, const char* pDocName, int resolve) const
+unsigned int SelectionSingleton::countObjectsOfType(const Base::Type& typeId, const char* pDocName, ResolveMode resolve) const
 {
     unsigned int iNbr=0;
     App::Document *pcDoc = nullptr;
-    if(!pDocName || strcmp(pDocName,"*")!=0) {
+    if(!pDocName || strcmp(pDocName,"*") != 0) {
         pcDoc = getDocument(pDocName);
         if (!pcDoc)
             return 0;
     }
 
     for (auto &sel : _SelList) {
-        if((!pcDoc||pcDoc==sel.pDoc) && getObjectOfType(sel,typeId,resolve))
+        if((!pcDoc||pcDoc==sel.pDoc) && getObjectOfType(sel, typeId, resolve))
             iNbr++;
     }
 
     return iNbr;
 }
 
-unsigned int SelectionSingleton::countObjectsOfType(const char* typeName, const char* pDocName, int resolve) const
+unsigned int SelectionSingleton::countObjectsOfType(const char* typeName, const char* pDocName, ResolveMode resolve) const
 {
     Base::Type typeId = Base::Type::fromName(typeName);
     if (typeId == Base::Type::badType())
@@ -715,7 +735,8 @@ unsigned int SelectionSingleton::countObjectsOfType(const char* typeName, const
 }
 
 
-void SelectionSingleton::slotSelectionChanged(const SelectionChanges& msg) {
+void SelectionSingleton::slotSelectionChanged(const SelectionChanges& msg)
+{
     if(msg.Type == SelectionChanges::SetPreselectSignal ||
        msg.Type == SelectionChanges::ShowSelection ||
        msg.Type == SelectionChanges::HideSelection)
@@ -723,13 +744,13 @@ void SelectionSingleton::slotSelectionChanged(const SelectionChanges& msg) {
 
     if(msg.Object.getSubName().size()) {
         auto pParent = msg.Object.getObject();
-        if(!pParent)
+        if(!pParent)
             return;
         std::pair<std::string,std::string> elementName;
         auto &newElementName = elementName.first;
         auto &oldElementName = elementName.second;
         auto pObject = App::GeoFeature::resolveElement(pParent,msg.pSubName,elementName);
-        if (!pObject)
+        if (!pObject)
             return;
         SelectionChanges msg2(msg.Type,pObject->getDocument()->getName(),
                 pObject->getNameInDocument(),
@@ -797,18 +818,18 @@ int SelectionSingleton::setPreselect(const char* pDocName, const char* pObjectNa
             return 0;
 
         const char *subelement = pSubName;
-        if(gateResolve) {
+        if (gateResolve != ResolveMode::NoResolve) {
             auto &newElementName = elementName.first;
             auto &oldElementName = elementName.second;
             pObject = App::GeoFeature::resolveElement(pObject,pSubName,elementName);
             if (!pObject)
                 return 0;
-            if(gateResolve > 1)
-                subelement = newElementName.size()?newElementName.c_str():oldElementName.c_str();
+            if (gateResolve > ResolveMode::OldStyleElement)
+                subelement = newElementName.size() ? newElementName.c_str() : oldElementName.c_str();
             else
                 subelement = oldElementName.c_str();
         }
-        if (!ActiveGate->allow(pObject->getDocument(),pObject,subelement)) {
+        if (!ActiveGate->allow(pObject->getDocument(), pObject, subelement)) {
             QString msg;
             if (ActiveGate->notAllowedReason.length() > 0){
                 msg = QObject::tr(ActiveGate->notAllowedReason.c_str());
@@ -894,7 +915,7 @@ void SelectionSingleton::setPreselectCoord( float x, float y, float z)
     static char buf[513];
 
     // if nothing is in preselect ignore
-    if(CurrentPreselection.Object.getObjectName().empty())
+    if(CurrentPreselection.Object.getObjectName().empty())
         return;
 
     CurrentPreselection.x = x;
@@ -955,7 +976,7 @@ const SelectionChanges &SelectionSingleton::getPreselection(void) const
 }
 
 // add a SelectionGate to control what is selectable
-void SelectionSingleton::addSelectionGate(Gui::SelectionGate *gate, int resolve)
+void SelectionSingleton::addSelectionGate(Gui::SelectionGate *gate, ResolveMode resolve)
 {
     if (ActiveGate)
         rmvSelectionGate();
@@ -1059,8 +1080,8 @@ bool SelectionSingleton::addSelection(const char* pDocName, const char* pObjectN
     }
 
     _SelObj temp;
-    int ret = checkSelection(pDocName,pObjectName,pSubName,0,temp);
-    if(ret!=0)
+    int ret = checkSelection(pDocName, pObjectName, pSubName, ResolveMode::NoResolve, temp);
+    if (ret!=0)
         return false;
 
     temp.x        = x;
@@ -1206,15 +1227,15 @@ void SelectionSingleton::selStackGoForward(int count) {
     getMainWindow()->updateActions();
 }
 
-std::vector<SelectionObject> SelectionSingleton::selStackGet(
-        const char* pDocName, int resolve, int index) const
+std::vector<SelectionObject> SelectionSingleton::selStackGet(const char* pDocName, ResolveMode resolve, int index) const
 {
     const SelStackItem *item = nullptr;
-    if(index>=0) {
-        if(index>=(int)_SelStackBack.size())
+    if (index >= 0) {
+        if(index >= (int)_SelStackBack.size())
             return {};
         item = &_SelStackBack[_SelStackBack.size()-1-index];
-    }else{
+    }
+    else {
         index = -index-1;
         if(index>=(int)_SelStackForward.size())
             return {};
@@ -1227,7 +1248,7 @@ std::vector<SelectionObject> SelectionSingleton::selStackGet(
         if(checkSelection(sobjT.getDocumentName().c_str(),
                           sobjT.getObjectName().c_str(),
                           sobjT.getSubName().c_str(),
-                          0,
+                          ResolveMode::NoResolve,
                           sel,
                           &selList)==0)
         {
@@ -1235,7 +1256,7 @@ std::vector<SelectionObject> SelectionSingleton::selStackGet(
         }
     }
 
-    return getObjectList(pDocName,App::DocumentObject::getClassTypeId(),selList,resolve);
+    return getObjectList(pDocName,App::DocumentObject::getClassTypeId(), selList, resolve);
 }
 
 bool SelectionSingleton::addSelections(const char* pDocName, const char* pObjectName, const std::vector<std::string>& pSubNames)
@@ -1248,8 +1269,8 @@ bool SelectionSingleton::addSelections(const char* pDocName, const char* pObject
     bool update = false;
     for(std::vector<std::string>::const_iterator it = pSubNames.begin(); it != pSubNames.end(); ++it) {
         _SelObj temp;
-        int ret = checkSelection(pDocName,pObjectName,it->c_str(),0,temp);
-        if(ret!=0)
+        int ret = checkSelection(pDocName, pObjectName, it->c_str(), ResolveMode::NoResolve, temp);
+        if (ret!=0)
             continue;
 
         temp.x        = 0;
@@ -1288,12 +1309,12 @@ bool SelectionSingleton::updateSelection(bool show, const char* pDocName,
             rmvPreselect();
     }
     auto pDoc = getDocument(pDocName);
-    if(!pDoc)
+    if(!pDoc)
         return false;
     auto pObject = pDoc->getObject(pObjectName);
-    if(!pObject)
+    if(!pObject)
         return false;
-    if (!isSelected(pObject, pSubName,0))
+    if (!isSelected(pObject, pSubName, ResolveMode::NoResolve))
         return false;
 
     SelectionChanges Chng(show?SelectionChanges::ShowSelection:SelectionChanges::HideSelection,
@@ -1306,7 +1327,7 @@ bool SelectionSingleton::updateSelection(bool show, const char* pDocName,
     return true;
 }
 
-bool SelectionSingleton::addSelection(const SelectionObject& obj,bool clearPreselect)
+bool SelectionSingleton::addSelection(const SelectionObject& obj, bool clearPreselect)
 {
     const std::vector<std::string>& subNames = obj.getSubNames();
     const std::vector<Base::Vector3d> points = obj.getPickedPoints();
@@ -1357,12 +1378,12 @@ void SelectionSingleton::rmvSelection(const char* pDocName, const char* pObjectN
         notify(SelectionChanges(SelectionChanges::PickedListChanged));
     }
 
-    if(!pDocName)
+    if(!pDocName)
         return;
 
     _SelObj temp;
-    int ret = checkSelection(pDocName,pObjectName,pSubName,0,temp);
-    if(ret<0)
+    int ret = checkSelection(pDocName, pObjectName, pSubName, ResolveMode::NoResolve, temp);
+    if (ret<0)
         return;
 
     std::vector<SelectionChanges> changes;
@@ -1518,8 +1539,8 @@ void SelectionSingleton::setSelection(const char* pDocName, const std::vector<Ap
         if(!obj || !obj->getNameInDocument())
             continue;
         _SelObj temp;
-        int ret = checkSelection(pDocName,obj->getNameInDocument(),nullptr,0,temp);
-        if(ret!=0)
+        int ret = checkSelection(pDocName,obj->getNameInDocument(), nullptr, ResolveMode::NoResolve, temp);
+        if (ret!=0)
             continue;
         touched = true;
         _SelList.push_back(temp);
@@ -1527,7 +1548,7 @@ void SelectionSingleton::setSelection(const char* pDocName, const std::vector<Ap
 
     if(touched) {
         _SelStackForward.clear();
-        notify(SelectionChanges(SelectionChanges::SetSelection,pDocName));
+        notify(SelectionChanges(SelectionChanges::SetSelection, pDocName));
         getMainWindow()->updateActions();
     }
 }
@@ -1611,24 +1632,24 @@ void SelectionSingleton::clearCompleteSelection(bool clearPreSelect)
     getMainWindow()->updateActions();
 }
 
-bool SelectionSingleton::isSelected(const char* pDocName,
-        const char* pObjectName, const char* pSubName, int resolve) const
+bool SelectionSingleton::isSelected(const char* pDocName, const char* pObjectName,
+                                    const char* pSubName, ResolveMode resolve) const
 {
     _SelObj sel;
-    return checkSelection(pDocName,pObjectName,pSubName,resolve,sel,&_SelList)>0;
+    return checkSelection(pDocName, pObjectName, pSubName, resolve, sel, &_SelList) > 0;
 }
 
-bool SelectionSingleton::isSelected(App::DocumentObject* pObject, const char* pSubName, int resolve) const
+bool SelectionSingleton::isSelected(App::DocumentObject* pObject, const char* pSubName, ResolveMode resolve) const
 {
-    if(!pObject || !pObject->getNameInDocument() || !pObject->getDocument())
+    if (!pObject || !pObject->getNameInDocument() || !pObject->getDocument())
         return false;
     _SelObj sel;
     return checkSelection(pObject->getDocument()->getName(),
-            pObject->getNameInDocument(),pSubName,resolve,sel,&_SelList)>0;
+            pObject->getNameInDocument(), pSubName, resolve, sel, &_SelList) > 0;
 }
 
-int SelectionSingleton::checkSelection(const char *pDocName, const char *pObjectName,
-        const char *pSubName, int resolve, _SelObj &sel, const std::list<_SelObj> *selList) const
+int SelectionSingleton::checkSelection(const char *pDocName, const char *pObjectName, const char *pSubName,
+                                       ResolveMode resolve, _SelObj &sel, const std::list<_SelObj> *selList) const
 {
     sel.pDoc = getDocument(pDocName);
     if(!sel.pDoc) {
@@ -1648,11 +1669,11 @@ int SelectionSingleton::checkSelection(const char *pDocName, const char *pObject
             FC_ERR("Object not found");
         return -1;
     }
-    if(sel.pObject->testStatus(App::ObjectStatus::Remove))
+    if (sel.pObject->testStatus(App::ObjectStatus::Remove))
         return -1;
-    if(pSubName)
+    if (pSubName)
        sel.SubName = pSubName;
-    if(!resolve)
+    if (resolve == ResolveMode::NoResolve)
         TreeWidget::checkTopParent(sel.pObject,sel.SubName);
     pSubName = sel.SubName.size()?sel.SubName.c_str():nullptr;
     sel.FeatName = sel.pObject->getNameInDocument();
@@ -1688,20 +1709,21 @@ int SelectionSingleton::checkSelection(const char *pDocName, const char *pObject
         if (s.DocName==pDocName && s.FeatName==sel.FeatName) {
             if(s.SubName==pSubName)
                 return 1;
-            if(resolve>1 && boost::starts_with(s.SubName,prefix))
+            if (resolve > ResolveMode::OldStyleElement && boost::starts_with(s.SubName,prefix))
                 return 1;
         }
     }
-    if(resolve==1) {
+    if (resolve == ResolveMode::OldStyleElement) {
         for(auto &s : *selList) {
             if(s.pResolvedObject != sel.pResolvedObject)
                 continue;
             if(!pSubName[0])
                 return 1;
-            if(s.elementName.first.size()) {
-                if(s.elementName.first == sel.elementName.first)
+            if (s.elementName.first.size()) {
+                if (s.elementName.first == sel.elementName.first)
                     return 1;
-            }else if(s.SubName == sel.elementName.second)
+            }
+            else if(s.SubName == sel.elementName.second)
                 return 1;
         }
     }
@@ -1710,7 +1732,7 @@ int SelectionSingleton::checkSelection(const char *pDocName, const char *pObject
 
 const char *SelectionSingleton::getSelectedElement(App::DocumentObject *obj, const char* pSubName) const
 {
-    if (!obj)
+    if (!obj)
         return nullptr;
 
     for(list<_SelObj>::const_iterator It = _SelList.begin();It != _SelList.end();++It) {
@@ -1729,7 +1751,7 @@ const char *SelectionSingleton::getSelectedElement(App::DocumentObject *obj, con
 
 void SelectionSingleton::slotDeletedObject(const App::DocumentObject& Obj)
 {
-    if(!Obj.getNameInDocument())
+    if(!Obj.getNameInDocument())
         return;
 
     // For safety reason, don't bother checking
@@ -1787,7 +1809,7 @@ SelectionSingleton::SelectionSingleton()
     hy = 0;
     hz = 0;
     ActiveGate = nullptr;
-    gateResolve = 1;
+    gateResolve = ResolveMode::OldStyleElement;
     App::GetApplication().signalDeletedObject.connect(boost::bind(&Gui::SelectionSingleton::slotDeletedObject, this, bp::_1));
     signalSelectionChanged.connect(boost::bind(&Gui::SelectionSingleton::slotSelectionChanged, this, bp::_1));
 }
@@ -2171,19 +2193,41 @@ PyObject *SelectionSingleton::sClearSelection(PyObject * /*self*/, PyObject *arg
     Py_Return;
 }
 
+namespace {
+ResolveMode toEnum(int value) {
+    switch (value) {
+    case 0:
+        return ResolveMode::NoResolve;
+    case 1:
+        return ResolveMode::OldStyleElement;
+    case 2:
+        return ResolveMode::NewStyleElement;
+    case 3:
+        return ResolveMode::FollowLink;
+    default:
+        throw Base::ValueError("Wrong enum value");
+    }
+}
+}
+
 PyObject *SelectionSingleton::sIsSelected(PyObject * /*self*/, PyObject *args)
 {
     PyObject *object;
     char* subname = nullptr;
-    PyObject *resolve = Py_True;
-    if (!PyArg_ParseTuple(args, "O!|sO!", &(App::DocumentObjectPy::Type), &object,
-            &subname, &PyBool_Type, &resolve))
+    int resolve = 1;
+    if (!PyArg_ParseTuple(args, "O!|si", &(App::DocumentObjectPy::Type), &object, &subname, &resolve))
         return nullptr;
 
-    App::DocumentObjectPy* docObj = static_cast<App::DocumentObjectPy*>(object);
-    bool ok = Selection().isSelected(docObj->getDocumentObjectPtr(), subname,PyObject_IsTrue(resolve));
+    try {
+        App::DocumentObjectPy* docObj = static_cast<App::DocumentObjectPy*>(object);
+        bool ok = Selection().isSelected(docObj->getDocumentObjectPtr(), subname, toEnum(resolve));
 
-    return Py_BuildValue("O", (ok ? Py_True : Py_False));
+        return Py_BuildValue("O", (ok ? Py_True : Py_False));
+    }
+    catch (const Base::Exception& e) {
+        e.setPyException();
+        return nullptr;
+    }
 }
 
 PyObject *SelectionSingleton::sCountObjectsOfType(PyObject * /*self*/, PyObject *args)
@@ -2194,9 +2238,14 @@ PyObject *SelectionSingleton::sCountObjectsOfType(PyObject * /*self*/, PyObject
     if (!PyArg_ParseTuple(args, "s|si", &objecttype, &document,&resolve))
         return nullptr;
 
-    unsigned int count = Selection().countObjectsOfType(objecttype, document, resolve);
-
-    return PyLong_FromLong(count);
+    try {
+        unsigned int count = Selection().countObjectsOfType(objecttype, document, toEnum(resolve));
+        return PyLong_FromLong(count);
+    }
+    catch (const Base::Exception& e) {
+        e.setPyException();
+        return nullptr;
+    }
 }
 
 PyObject *SelectionSingleton::sGetSelection(PyObject * /*self*/, PyObject *args)
@@ -2207,10 +2256,10 @@ PyObject *SelectionSingleton::sGetSelection(PyObject * /*self*/, PyObject *args)
     if (!PyArg_ParseTuple(args, "|siO!", &documentName, &resolve, &PyBool_Type, &single))
         return nullptr;
 
-    std::vector<SelectionSingleton::SelObj> sel;
-    sel = Selection().getSelection(documentName,resolve,PyObject_IsTrue(single));
-
     try {
+        std::vector<SelectionSingleton::SelObj> sel;
+        sel = Selection().getSelection(documentName, toEnum(resolve), PyObject_IsTrue(single));
+
         std::set<App::DocumentObject*> noduplicates;
         std::vector<App::DocumentObject*> selectedObjects; // keep the order of selection
         Py::List list;
@@ -2224,6 +2273,10 @@ PyObject *SelectionSingleton::sGetSelection(PyObject * /*self*/, PyObject *args)
         }
         return Py::new_reference_to(list);
     }
+    catch (const Base::Exception& e) {
+        e.setPyException();
+        return nullptr;
+    }
     catch (Py::Exception&) {
         return nullptr;
     }
@@ -2294,16 +2347,20 @@ PyObject *SelectionSingleton::sGetCompleteSelection(PyObject * /*self*/, PyObjec
     if (!PyArg_ParseTuple(args, "|i",&resolve))
         return nullptr;
 
-    std::vector<SelectionSingleton::SelObj> sel;
-    sel = Selection().getCompleteSelection(resolve);
-
     try {
+        std::vector<SelectionSingleton::SelObj> sel;
+        sel = Selection().getCompleteSelection(toEnum(resolve));
+
         Py::List list;
         for (std::vector<SelectionSingleton::SelObj>::iterator it = sel.begin(); it != sel.end(); ++it) {
             list.append(Py::asObject(it->pObject->getPyObject()));
         }
         return Py::new_reference_to(list);
     }
+    catch (const Base::Exception& e) {
+        e.setPyException();
+        return nullptr;
+    }
     catch (Py::Exception&) {
         return nullptr;
     }
@@ -2317,17 +2374,21 @@ PyObject *SelectionSingleton::sGetSelectionEx(PyObject * /*self*/, PyObject *arg
     if (!PyArg_ParseTuple(args, "|siO!", &documentName, &resolve, &PyBool_Type, &single))
         return nullptr;
 
-    std::vector<SelectionObject> sel;
-    sel = Selection().getSelectionEx(documentName,
-            App::DocumentObject::getClassTypeId(),resolve,PyObject_IsTrue(single));
-
     try {
+        std::vector<SelectionObject> sel;
+        sel = Selection().getSelectionEx(documentName,
+                App::DocumentObject::getClassTypeId(), toEnum(resolve), PyObject_IsTrue(single));
+
         Py::List list;
         for (std::vector<SelectionObject>::iterator it = sel.begin(); it != sel.end(); ++it) {
             list.append(Py::asObject(it->getPyObject()));
         }
         return Py::new_reference_to(list);
     }
+    catch (const Base::Exception& e) {
+        e.setPyException();
+        return nullptr;
+    }
     catch (Py::Exception&) {
         return nullptr;
     }
@@ -2396,7 +2457,7 @@ PyObject *SelectionSingleton::sAddSelObserver(PyObject * /*self*/, PyObject *arg
         return nullptr;
 
     PY_TRY {
-        SelectionObserverPython::addObserver(Py::Object(o),resolve);
+        SelectionObserverPython::addObserver(Py::Object(o), toEnum(resolve));
         Py_Return;
     }
     PY_CATCH;
@@ -2421,7 +2482,7 @@ PyObject *SelectionSingleton::sAddSelectionGate(PyObject * /*self*/, PyObject *a
     int resolve = 1;
     if (PyArg_ParseTuple(args, "s|i", &filter, &resolve)) {
         PY_TRY {
-            Selection().addSelectionGate(new SelectionFilterGate(filter),resolve);
+            Selection().addSelectionGate(new SelectionFilterGate(filter), toEnum(resolve));
             Py_Return;
         }
         PY_CATCH;
@@ -2432,7 +2493,7 @@ PyObject *SelectionSingleton::sAddSelectionGate(PyObject * /*self*/, PyObject *a
     if (PyArg_ParseTuple(args, "O!|i",SelectionFilterPy::type_object(),&filterPy,resolve)) {
         PY_TRY {
             Selection().addSelectionGate(new SelectionFilterGatePython(
-                        static_cast<SelectionFilterPy*>(filterPy)),resolve);
+                        static_cast<SelectionFilterPy*>(filterPy)), toEnum(resolve));
             Py_Return;
         }
         PY_CATCH;
@@ -2442,7 +2503,7 @@ PyObject *SelectionSingleton::sAddSelectionGate(PyObject * /*self*/, PyObject *a
     PyObject* gate;
     if (PyArg_ParseTuple(args, "O|i",&gate,&resolve)) {
         PY_TRY {
-            Selection().addSelectionGate(new SelectionGatePython(Py::Object(gate, false)),resolve);
+            Selection().addSelectionGate(new SelectionGatePython(Py::Object(gate, false)), toEnum(resolve));
             Py_Return;
         }
          PY_CATCH;
@@ -2505,14 +2566,14 @@ PyObject *SelectionSingleton::sPushSelStack(PyObject * /*self*/, PyObject *args)
 PyObject *SelectionSingleton::sHasSelection(PyObject * /*self*/, PyObject *args)
 {
     const char *doc = nullptr;
-    PyObject *resolve = Py_False;
-    if (!PyArg_ParseTuple(args, "|sO!", &doc, &PyBool_Type, &resolve))
+    int resolve = 0;
+    if (!PyArg_ParseTuple(args, "|sO!", &doc, &resolve))
         return nullptr;
 
     PY_TRY {
         bool ret;
-        if(doc || PyObject_IsTrue(resolve))
-            ret = Selection().hasSelection(doc,PyObject_IsTrue(resolve));
+        if (doc || resolve > 0)
+            ret = Selection().hasSelection(doc, toEnum(resolve));
         else
             ret = Selection().hasSelection();
 
@@ -2545,7 +2606,7 @@ PyObject *SelectionSingleton::sGetSelectionFromStack(PyObject * /*self*/, PyObje
 
     PY_TRY {
         Py::List list;
-        for(auto &sel : Selection().selStackGet(documentName, resolve, index))
+        for(auto &sel : Selection().selStackGet(documentName, toEnum(resolve), index))
             list.append(Py::asObject(sel.getPyObject()));
         return Py::new_reference_to(list);
     }
diff --git a/src/Gui/Selection.h b/src/Gui/Selection.h
index 926b276105..9b3545d652 100644
--- a/src/Gui/Selection.h
+++ b/src/Gui/Selection.h
@@ -47,8 +47,15 @@ namespace App
 namespace Gui
 {
 
-    class SelectionObject;
-    class SelectionFilter;
+enum class ResolveMode {
+    NoResolve,
+    OldStyleElement,
+    NewStyleElement,
+    FollowLink
+};
+
+class SelectionObject;
+class SelectionFilter;
 
 /** Transport the changes of the Selection
  * This class transports closer information what was changed in the
@@ -213,7 +220,7 @@ public:
      *                 1 resolve sub-object with old style element name
      *                 2 resolve sub-object with new style element name
      */
-    SelectionObserver(bool attach = true, int resolve = 1);
+    SelectionObserver(bool attach = true, ResolveMode resolve = ResolveMode::OldStyleElement);
     /** Constructor
      *
      * @param vp: filtering view object.
@@ -226,7 +233,7 @@ public:
      * Constructs an selection observer that receives only selection event of
      * objects within the same document as the input view object.
      */
-    SelectionObserver(const Gui::ViewProviderDocumentObject *vp, bool attach=true, int resolve=1);
+    SelectionObserver(const Gui::ViewProviderDocumentObject *vp, bool attach=true, ResolveMode resolve = ResolveMode::OldStyleElement);
 
     virtual ~SelectionObserver();
     bool blockSelection(bool block);
@@ -247,7 +254,7 @@ private:
     Connection connectSelection;
     std::string filterDocName;
     std::string filterObjName;
-    int resolve;
+    ResolveMode resolve;
     bool blockedSelection;
 };
 
@@ -263,10 +270,10 @@ class GuiExport SelectionObserverPython : public SelectionObserver
 
 public:
     /// Constructor
-    SelectionObserverPython(const Py::Object& obj, int resolve=1);
+    SelectionObserverPython(const Py::Object& obj, ResolveMode resolve = ResolveMode::OldStyleElement);
     virtual ~SelectionObserverPython();
 
-    static void addObserver(const Py::Object& obj, int resolve=1);
+    static void addObserver(const Py::Object& obj, ResolveMode resolve = ResolveMode::OldStyleElement);
     static void removeObserver(const Py::Object& obj);
 
 private:
@@ -387,9 +394,9 @@ public:
     void clearCompleteSelection(bool clearPreSelect=true);
     /// Check if selected
     bool isSelected(const char* pDocName, const char* pObjectName=nullptr,
-            const char* pSubName=nullptr, int resolve=1) const;
+            const char* pSubName=nullptr, ResolveMode resolve = ResolveMode::OldStyleElement) const;
     /// Check if selected
-    bool isSelected(App::DocumentObject*, const char* pSubName=nullptr, int resolve=1) const;
+    bool isSelected(App::DocumentObject*, const char* pSubName=nullptr, ResolveMode resolve = ResolveMode::OldStyleElement) const;
 
     const char *getSelectedElement(App::DocumentObject*, const char* pSubName) const;
 
@@ -403,7 +410,7 @@ public:
     /// returns the present preselection
     const SelectionChanges& getPreselection(void) const;
     /// add a SelectionGate to control what is selectable
-    void addSelectionGate(Gui::SelectionGate *gate, int resolve = 1);
+    void addSelectionGate(Gui::SelectionGate *gate, ResolveMode resolve = ResolveMode::OldStyleElement);
     /// remove the active SelectionGate
     void rmvSelectionGate(void);
 
@@ -420,14 +427,14 @@ public:
      * field
      */
     unsigned int countObjectsOfType(const Base::Type& typeId=App::DocumentObject::getClassTypeId(),
-            const char* pDocName=nullptr, int resolve=1) const;
+            const char* pDocName=nullptr, ResolveMode resolve = ResolveMode::OldStyleElement) const;
 
     /**
      * Does basically the same as the method above unless that it accepts a string literal as first argument.
      * \a typeName must be a registered type, otherwise 0 is returned.
      */
     unsigned int countObjectsOfType(const char* typeName,
-            const char* pDocName=nullptr, int resolve=1) const;
+            const char* pDocName=nullptr, ResolveMode resolve = ResolveMode::OldStyleElement) const;
 
     /** Returns a vector of objects of type \a TypeName selected for the given document name \a pDocName.
      * If no document name is specified the objects from the active document are regarded.
@@ -435,19 +442,19 @@ public:
      * @note The vector reflects the sequence of selection.
      */
     std::vector<App::DocumentObject*> getObjectsOfType(const Base::Type& typeId,
-            const char* pDocName=nullptr, int resolve=1) const;
+            const char* pDocName=nullptr, ResolveMode resolve = ResolveMode::OldStyleElement) const;
 
     /**
      * Does basically the same as the method above unless that it accepts a string literal as first argument.
      * \a typeName must be a registered type otherwise an empty array is returned.
      */
     std::vector<App::DocumentObject*> getObjectsOfType(const char* typeName,
-            const char* pDocName=nullptr, int resolve=1) const;
+            const char* pDocName=nullptr, ResolveMode resolve = ResolveMode::OldStyleElement) const;
     /**
      * A convenience template-based method that returns an array with the correct types already.
      */
     template<typename T> inline std::vector<T*> getObjectsOfType(
-            const char* pDocName=nullptr, int resolve=1) const;
+            const char* pDocName=nullptr, ResolveMode resolve = ResolveMode::OldStyleElement) const;
 
     /// Visible state used by setVisible()
     enum VisibleState {
@@ -488,7 +495,7 @@ public:
      *
      * @return The returned vector reflects the sequence of selection.
      */
-    std::vector<SelObj> getSelection(const char* pDocName=nullptr, int resolve=1, bool single=false) const;
+    std::vector<SelObj> getSelection(const char* pDocName=nullptr, ResolveMode resolve = ResolveMode::OldStyleElement, bool single=false) const;
     /** Returns a vector of selection objects
      *
      * @param pDocName: document name. If no document name is given the objects
@@ -506,7 +513,7 @@ public:
      * @return The returned vector reflects the sequence of selection.
      */
     std::vector<Gui::SelectionObject> getSelectionEx(const char* pDocName=nullptr,
-            Base::Type typeId=App::DocumentObject::getClassTypeId(),int resolve=1, bool single=false) const;
+            Base::Type typeId=App::DocumentObject::getClassTypeId(), ResolveMode resolve = ResolveMode::OldStyleElement, bool single=false) const;
 
     /**
      * @brief getAsPropertyLinkSubList fills PropertyLinkSubList with current selection.
@@ -516,7 +523,7 @@ public:
     int getAsPropertyLinkSubList(App::PropertyLinkSubList &prop) const;
 
     /** Returns a vector of all selection objects of all documents. */
-    std::vector<SelObj> getCompleteSelection(int resolve=1) const;
+    std::vector<SelObj> getCompleteSelection(ResolveMode resolve = ResolveMode::OldStyleElement) const;
 
     /// Check if there is any selection
     bool hasSelection() const;
@@ -533,7 +540,7 @@ public:
      * If \c resolve is false, then the match is only done with the top
      * level parent object.
      */
-    bool hasSelection(const char* doc, bool resolve=true) const;
+    bool hasSelection(const char* doc, ResolveMode resolve = ResolveMode::OldStyleElement) const;
 
     /** Check if there is any sub-element selection
      *
@@ -576,7 +583,7 @@ public:
      *                 2 resolve sub-object with new style element name
      * @param index: optional position in the stack
      */
-    std::vector<Gui::SelectionObject> selStackGet(const char* pDocName=nullptr,int resolve=1,int index=0) const;
+    std::vector<Gui::SelectionObject> selStackGet(const char* pDocName=nullptr, ResolveMode resolve = ResolveMode::OldStyleElement, int index=0) const;
 
     /** Go back selection history
      *
@@ -708,12 +715,12 @@ protected:
     std::deque<SelStackItem> _SelStackForward;
 
     int checkSelection(const char *pDocName, const char *pObjectName,
-            const char *pSubName,int resolve, _SelObj &sel, const std::list<_SelObj> *selList=nullptr) const;
+            const char *pSubName, ResolveMode resolve, _SelObj &sel, const std::list<_SelObj> *selList=nullptr) const;
 
-    std::vector<Gui::SelectionObject> getObjectList(const char* pDocName,Base::Type typeId, std::list<_SelObj> &objs, int resolve, bool single=false) const;
+    std::vector<Gui::SelectionObject> getObjectList(const char* pDocName,Base::Type typeId, std::list<_SelObj> &objs, ResolveMode resolve, bool single=false) const;
 
     static App::DocumentObject *getObjectOfType(_SelObj &sel, Base::Type type,
-            int resolve, const char **subelement=nullptr);
+            ResolveMode resolve, const char **subelement=nullptr);
 
     static SelectionSingleton* _pcSingleton;
 
@@ -723,7 +730,7 @@ protected:
     float hx,hy,hz;
 
     Gui::SelectionGate *ActiveGate;
-    int gateResolve;
+    ResolveMode gateResolve;
 
     int logDisabled = 0;
     bool logHasSelection = false;
@@ -733,7 +740,7 @@ protected:
  * A convenience template-based method that returns an array with the correct types already.
  */
 template<typename T>
-inline std::vector<T*> SelectionSingleton::getObjectsOfType(const char* pDocName, int resolve) const
+inline std::vector<T*> SelectionSingleton::getObjectsOfType(const char* pDocName, ResolveMode resolve) const
 {
     std::vector<T*> type;
     std::vector<App::DocumentObject*> obj = this->getObjectsOfType(T::getClassTypeId(), pDocName, resolve);
diff --git a/src/Gui/SelectionView.cpp b/src/Gui/SelectionView.cpp
index d0d90d43b2..9b62ff34a5 100644
--- a/src/Gui/SelectionView.cpp
+++ b/src/Gui/SelectionView.cpp
@@ -54,7 +54,7 @@ using namespace Gui::DockWnd;
 
 SelectionView::SelectionView(Gui::Document* pcDocument, QWidget *parent)
   : DockWindow(pcDocument,parent)
-  , SelectionObserver(true,0)
+  , SelectionObserver(true, ResolveMode::NoResolve)
   , x(0.0f), y(0.0f), z(0.0f)
   , openedAutomatically(false)
 {
@@ -201,7 +201,7 @@ void SelectionView::onSelectionChanged(const SelectionChanges &Reason)
     else if (Reason.Type == SelectionChanges::SetSelection) {
         // remove all items
         selectionView->clear();
-        std::vector<SelectionSingleton::SelObj> objs = Gui::Selection().getSelection(Reason.pDocName,0);
+        std::vector<SelectionSingleton::SelObj> objs = Gui::Selection().getSelection(Reason.pDocName, ResolveMode::NoResolve);
         for (std::vector<SelectionSingleton::SelObj>::iterator it = objs.begin(); it != objs.end(); ++it) {
             // save as user data
             QStringList list;
@@ -360,12 +360,12 @@ void SelectionView::deselect(void)
 
 void SelectionView::toggleSelect(QListWidgetItem* item)
 {
-    if (!item)
+    if (!item)
         return;
     std::string name = item->text().toLatin1().constData();
     char *docname = &name.at(0);
     char *objname = std::strchr(docname,'#');
-    if(!objname)
+    if(!objname)
         return;
     *objname++ = 0;
     char *subname = std::strchr(objname,'.');
@@ -400,12 +400,12 @@ void SelectionView::toggleSelect(QListWidgetItem* item)
 
 void SelectionView::preselect(QListWidgetItem* item)
 {
-    if (!item)
+    if (!item)
         return;
     std::string name = item->text().toLatin1().constData();
     char *docname = &name.at(0);
     char *objname = std::strchr(docname,'#');
-    if(!objname)
+    if(!objname)
         return;
     *objname++ = 0;
     char *subname = std::strchr(objname,'.');
diff --git a/src/Gui/SoFCUnifiedSelection.cpp b/src/Gui/SoFCUnifiedSelection.cpp
index 12274ce71a..0de6df63a1 100644
--- a/src/Gui/SoFCUnifiedSelection.cpp
+++ b/src/Gui/SoFCUnifiedSelection.cpp
@@ -204,7 +204,7 @@ void SoFCUnifiedSelection::write(SoWriteAction * action)
     SoOutput * out = action->getOutput();
     if (out->getStage() == SoOutput::WRITE) {
         // Do not write out the fields of this class
-        if (this->writeHeader(out, true, false))
+        if (this->writeHeader(out, true, false))
             return;
         SoGroup::doAction((SoAction *)action);
         this->writeFooter(out);
@@ -217,13 +217,13 @@ void SoFCUnifiedSelection::write(SoWriteAction * action)
 int SoFCUnifiedSelection::getPriority(const SoPickedPoint* p)
 {
     const SoDetail* detail = p->getDetail();
-    if (!detail)
+    if (!detail)
         return 0;
-    if (detail->isOfType(SoFaceDetail::getClassTypeId()))
+    if (detail->isOfType(SoFaceDetail::getClassTypeId()))
         return 1;
-    if (detail->isOfType(SoLineDetail::getClassTypeId()))
+    if (detail->isOfType(SoLineDetail::getClassTypeId()))
         return 2;
-    if (detail->isOfType(SoPointDetail::getClassTypeId()))
+    if (detail->isOfType(SoPointDetail::getClassTypeId()))
         return 3;
     return 0;
 }
@@ -268,7 +268,7 @@ SoFCUnifiedSelection::getPickedList(SoHandleEventAction* action, bool singlePick
         ret.push_back(info);
     }
 
-    if(ret.size()<=1)
+    if(ret.size()<=1)
         return ret;
 
     // To identify the picking of lines in a concave area we have to
@@ -540,7 +540,7 @@ bool SoFCUnifiedSelection::setHighlight(SoFullPath *path, const SoDetail *det,
 }
 
 bool SoFCUnifiedSelection::setSelection(const std::vector<PickedInfo> &infos, bool ctrlDown) {
-    if(infos.empty() || !infos[0].vpd)
+    if(infos.empty() || !infos[0].vpd)
         return false;
 
     std::vector<SelectionSingleton::SelObj> sels;
@@ -566,10 +566,10 @@ bool SoFCUnifiedSelection::setSelection(const std::vector<PickedInfo> &infos, bo
 
     const auto &info = infos[0];
     auto vpd = info.vpd;
-    if(!vpd)
+    if(!vpd)
         return false;
     const char *objname = vpd->getObject()->getNameInDocument();
-    if(!objname)
+    if(!objname)
         return false;
     const char *docname = vpd->getObject()->getDocument()->getName();
 
@@ -584,8 +584,8 @@ bool SoFCUnifiedSelection::setSelection(const std::vector<PickedInfo> &infos, bo
     static char buf[513];
 
     if (ctrlDown) {
-        if(Gui::Selection().isSelected(docname,objname,info.element.c_str(),0))
-            Gui::Selection().rmvSelection(docname,objname,info.element.c_str(),&sels);
+        if(Gui::Selection().isSelected(docname, objname, info.element.c_str(), ResolveMode::NoResolve))
+            Gui::Selection().rmvSelection(docname, objname,info.element.c_str(), &sels);
         else {
             bool ok = Gui::Selection().addSelection(docname,objname,
                     info.element.c_str(), pt[0] ,pt[1] ,pt[2], &sels);
diff --git a/src/Gui/TaskElementColors.cpp b/src/Gui/TaskElementColors.cpp
index 08452e1e8d..635e4410a9 100644
--- a/src/Gui/TaskElementColors.cpp
+++ b/src/Gui/TaskElementColors.cpp
@@ -271,12 +271,12 @@ public:
     }
 
     void onSelectionChanged() {
-        if(busy)
+        if(busy)
             return;
         busy = true;
         std::map<std::string,int> sels;
         for(auto &sel : Selection().getSelectionEx(
-                    editDoc.c_str(),App::DocumentObject::getClassTypeId(),0))
+                    editDoc.c_str(),App::DocumentObject::getClassTypeId(), ResolveMode::NoResolve))
         {
             if(sel.getFeatName()!=editObj) continue;
             for(auto &sub : sel.getSubNames()) {
@@ -324,7 +324,7 @@ ElementColors::ElementColors(ViewProviderDocumentObject* vp, bool noHide)
     if(d->ui->onTop->isChecked())
         d->vpParent->OnTopWhenSelected.setValue(3);
 
-    Selection().addSelectionGate(d,0);
+    Selection().addSelectionGate(d, ResolveMode::NoResolve);
 
     d->connectDelDoc = Application::Instance->signalDeleteDocument.connect(boost::bind
         (&ElementColors::slotDeleteDocument, this, bp::_1));
@@ -379,7 +379,7 @@ void ElementColors::on_boxSelect_clicked()
 }
 
 void ElementColors::on_hideSelection_clicked() {
-    auto sels = Selection().getSelectionEx(d->editDoc.c_str(),App::DocumentObject::getClassTypeId(),0);
+    auto sels = Selection().getSelectionEx(d->editDoc.c_str(), App::DocumentObject::getClassTypeId(), ResolveMode::NoResolve);
     for(auto &sel : sels) {
         if(d->editObj!=sel.getFeatName())
             continue;
@@ -400,7 +400,7 @@ void ElementColors::on_hideSelection_clicked() {
 
 void ElementColors::on_addSelection_clicked()
 {
-    auto sels = Selection().getSelectionEx(d->editDoc.c_str(),App::DocumentObject::getClassTypeId(),0);
+    auto sels = Selection().getSelectionEx(d->editDoc.c_str(), App::DocumentObject::getClassTypeId(), ResolveMode::NoResolve);
     d->items.clear();
     if(sels.empty())
         d->addItem(-1,"Face",true);
diff --git a/src/Gui/Tree.cpp b/src/Gui/Tree.cpp
index b805759295..d27301a4a5 100644
--- a/src/Gui/Tree.cpp
+++ b/src/Gui/Tree.cpp
@@ -429,9 +429,13 @@ QWidget* TreeWidgetEditDelegate::createEditor(
 // ---------------------------------------------------------------------------
 
 TreeWidget::TreeWidget(const char* name, QWidget* parent)
-    : QTreeWidget(parent), SelectionObserver(true, 0), contextItem(nullptr)
-    , searchObject(nullptr), searchDoc(nullptr), searchContextDoc(nullptr)
-    , editingItem(nullptr), currentDocItem(nullptr)
+    : QTreeWidget(parent), SelectionObserver(true, ResolveMode::NoResolve)
+    , contextItem(nullptr)
+    , searchObject(nullptr)
+    , searchDoc(nullptr)
+    , searchContextDoc(nullptr)
+    , editingItem(nullptr)
+    , currentDocItem(nullptr)
     , myName(name)
 {
     Instances.insert(this);
@@ -1060,7 +1064,7 @@ void TreeWidget::onFinishEditing()
         DocumentObjectItem* objitem = static_cast<DocumentObjectItem*>
             (this->contextItem);
         App::DocumentObject* obj = objitem->object()->getObject();
-        if (!obj)
+        if (!obj)
             return;
         Gui::Document* doc = Gui::Application::Instance->getDocument(obj->getDocument());
         doc->commitCommand();
@@ -1239,7 +1243,7 @@ std::vector<TreeWidget::SelInfo> TreeWidget::getSelection(App::Document* doc)
                 break;
             }
     }
-    if (!tree)
+    if (!tree)
         return ret;
 
     if (tree->selectTimer->isActive())
@@ -1440,14 +1444,14 @@ void TreeWidget::keyPressEvent(QKeyEvent* event)
 void TreeWidget::mouseDoubleClickEvent(QMouseEvent* event)
 {
     QTreeWidgetItem* item = itemAt(event->pos());
-    if (!item)
+    if (!item)
         return;
 
     try {
         if (item->type() == TreeWidget::DocumentType) {
             //QTreeWidget::mouseDoubleClickEvent(event);
             Gui::Document* doc = static_cast<DocumentItem*>(item)->document();
-            if (!doc)
+            if (!doc)
                 return;
             if (doc->getDocument()->testStatus(App::Document::PartialDoc)) {
                 contextItem = item;
@@ -2752,7 +2756,7 @@ void TreeWidget::scrollItemToTop()
 
         tree->_updateStatus(false);
 
-        if (doc && Gui::Selection().hasSelection(doc->getDocument()->getName(), false)) {
+        if (doc && Gui::Selection().hasSelection(doc->getDocument()->getName(), ResolveMode::NoResolve)) {
             auto it = tree->DocumentMap.find(doc);
             if (it != tree->DocumentMap.end()) {
                 bool lock = tree->blockSelection(true);
@@ -2871,7 +2875,7 @@ void TreeWidget::syncView(ViewProviderDocumentObject* vp)
 
 void TreeWidget::onShowHidden()
 {
-    if (!this->contextItem)
+    if (!this->contextItem)
         return;
     DocumentItem* docItem = nullptr;
     if (this->contextItem->type() == DocumentType)
@@ -4149,7 +4153,7 @@ void DocumentItem::updateSelection(QTreeWidgetItem* ti, bool unselect) {
         }
     }
 
-    if (unselect)
+    if (unselect)
         return;
     for (int i = 0, count = ti->childCount(); i < count; ++i)
         updateSelection(ti->child(i));
@@ -4419,7 +4423,7 @@ DocumentObjectItem* DocumentItem::findItem(
 }
 
 void DocumentItem::selectItems(SelectionReason reason) {
-    const auto& sels = Selection().getSelection(pDocument->getDocument()->getName(), false);
+    const auto& sels = Selection().getSelection(pDocument->getDocument()->getName(), ResolveMode::NoResolve);
 
     bool sync = (sels.size() > 50 || reason == SR_SELECT) ? false : true;
 
@@ -4475,7 +4479,7 @@ void DocumentItem::selectItems(SelectionReason reason) {
 
 void DocumentItem::populateParents(const ViewProvider* vp, ViewParentMap& parentMap) {
     auto it = parentMap.find(vp);
-    if (it == parentMap.end())
+    if (it == parentMap.end())
         return;
     for (auto parent : it->second) {
         auto it = ObjectMap.find(parent->getObject());
diff --git a/src/Gui/View3DInventorViewer.cpp b/src/Gui/View3DInventorViewer.cpp
index 9863c86d49..adf2a22175 100644
--- a/src/Gui/View3DInventorViewer.cpp
+++ b/src/Gui/View3DInventorViewer.cpp
@@ -293,19 +293,37 @@ public:
 // *************************************************************************
 
 View3DInventorViewer::View3DInventorViewer(QWidget* parent, const QtGLWidget* sharewidget)
-    : Quarter::SoQTQuarterAdaptor(parent, sharewidget), SelectionObserver(false,0),
-      editViewProvider(nullptr), navigation(nullptr),
-      renderType(Native), framebuffer(nullptr), axisCross(nullptr), axisGroup(nullptr), editing(false), redirected(false),
-      allowredir(false), overrideMode("As Is"), _viewerPy(nullptr)
+    : Quarter::SoQTQuarterAdaptor(parent, sharewidget)
+    , SelectionObserver(false, ResolveMode::NoResolve)
+    , editViewProvider(nullptr)
+    , navigation(nullptr)
+    , renderType(Native)
+    , framebuffer(nullptr)
+    , axisCross(nullptr)
+    , axisGroup(nullptr)
+    , editing(false)
+    , redirected(false)
+    , allowredir(false)
+    , overrideMode("As Is")
+    , _viewerPy(nullptr)
 {
     init();
 }
 
 View3DInventorViewer::View3DInventorViewer(const QtGLFormat& format, QWidget* parent, const QtGLWidget* sharewidget)
-    : Quarter::SoQTQuarterAdaptor(format, parent, sharewidget), SelectionObserver(false,0),
-      editViewProvider(nullptr), navigation(nullptr),
-      renderType(Native), framebuffer(nullptr), axisCross(nullptr), axisGroup(nullptr), editing(false), redirected(false),
-      allowredir(false), overrideMode("As Is"), _viewerPy(nullptr)
+    : Quarter::SoQTQuarterAdaptor(format, parent, sharewidget)
+    , SelectionObserver(false, ResolveMode::NoResolve)
+    , editViewProvider(nullptr)
+    , navigation(nullptr)
+    , renderType(Native)
+    , framebuffer(nullptr)
+    , axisCross(nullptr)
+    , axisGroup(nullptr)
+    , editing(false)
+    , redirected(false)
+    , allowredir(false)
+    , overrideMode("As Is")
+    , _viewerPy(nullptr)
 {
     init();
 }
@@ -646,7 +664,7 @@ void View3DInventorViewer::setDocument(Gui::Document* pcDocument)
     selectionRoot->pcDocument = pcDocument;
 
     if(pcDocument) {
-        const auto &sels = Selection().getSelection(pcDocument->getDocument()->getName(),0);
+        const auto &sels = Selection().getSelection(pcDocument->getDocument()->getName(), ResolveMode::NoResolve);
         for(auto &sel : sels) {
             SelectionChanges Chng(SelectionChanges::ShowSelection,
                     sel.DocName,sel.FeatName,sel.SubName);
@@ -3058,7 +3076,7 @@ void View3DInventorViewer::viewAll(float factor)
 void View3DInventorViewer::viewSelection()
 {
     Base::BoundBox3d bbox;
-    for(auto &sel : Selection().getSelection(nullptr,0)) {
+    for(auto &sel : Selection().getSelection(nullptr, ResolveMode::NoResolve)) {
         auto vp = Application::Instance->getViewProvider(sel.pObject);
         if(!vp)
             continue;
diff --git a/src/Mod/MeshPart/Gui/Tessellation.cpp b/src/Mod/MeshPart/Gui/Tessellation.cpp
index ce7f1bfe41..a0f5ac1bc1 100644
--- a/src/Mod/MeshPart/Gui/Tessellation.cpp
+++ b/src/Mod/MeshPart/Gui/Tessellation.cpp
@@ -193,7 +193,7 @@ void Tessellation::on_estimateMaximumEdgeLength_clicked()
     }
 
     double edgeLen = 0;
-    for (auto &sel : Gui::Selection().getSelection("*",0)) {
+    for (auto &sel : Gui::Selection().getSelection("*", Gui::ResolveMode::NoResolve)) {
         auto shape = Part::Feature::getTopoShape(sel.pObject,sel.SubName);
         if (shape.hasSubShape(TopAbs_FACE)) {
             Base::BoundBox3d bbox = shape.getBoundBox();
@@ -225,7 +225,7 @@ bool Tessellation::accept()
 
     bool bodyWithNoTip = false;
     bool partWithNoFace = false;
-    for (auto &sel : Gui::Selection().getSelection("*",0)) {
+    for (auto &sel : Gui::Selection().getSelection("*", Gui::ResolveMode::NoResolve)) {
         auto shape = Part::Feature::getTopoShape(sel.pObject,sel.SubName);
         if (shape.hasSubShape(TopAbs_FACE)) {
             shapeObjects.emplace_back(sel.pObject, sel.SubName);
diff --git a/src/Mod/Part/Gui/Command.cpp b/src/Mod/Part/Gui/Command.cpp
index 28ddf79631..ccb2857d2b 100644
--- a/src/Mod/Part/Gui/Command.cpp
+++ b/src/Mod/Part/Gui/Command.cpp
@@ -307,7 +307,7 @@ void CmdPartCut::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
     std::vector<Gui::SelectionObject> Sel = 
-        getSelection().getSelectionEx(nullptr, App::DocumentObject::getClassTypeId(),3);
+        getSelection().getSelectionEx(nullptr, App::DocumentObject::getClassTypeId(), Gui::ResolveMode::FollowLink);
     if (Sel.size() != 2) {
         QMessageBox::warning(Gui::getMainWindow(), QObject::tr("Wrong selection"),
             QObject::tr("Select two shapes please."));
@@ -361,7 +361,7 @@ void CmdPartCut::activated(int iMsg)
 bool CmdPartCut::isActive(void)
 {
     return getSelection().countObjectsOfType(
-            App::DocumentObject::getClassTypeId(),nullptr,3)==2;
+            App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink)==2;
 }
 
 //===========================================================================
@@ -385,7 +385,7 @@ void CmdPartCommon::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
     std::vector<Gui::SelectionObject> Sel = 
-        getSelection().getSelectionEx(nullptr, App::DocumentObject::getClassTypeId(), 3);
+        getSelection().getSelectionEx(nullptr, App::DocumentObject::getClassTypeId(), Gui::ResolveMode::FollowLink);
 
     //test if selected object is a compound, and if it is, look how many children it has...
     std::size_t numShapes = 0;
@@ -461,7 +461,7 @@ void CmdPartCommon::activated(int iMsg)
 bool CmdPartCommon::isActive(void)
 {
     return getSelection().countObjectsOfType(
-            App::DocumentObject::getClassTypeId(),nullptr,3)>=1;
+            App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink) >= 1;
 }
 
 //===========================================================================
@@ -485,7 +485,7 @@ void CmdPartFuse::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
     std::vector<Gui::SelectionObject> Sel = 
-        getSelection().getSelectionEx(nullptr, App::DocumentObject::getClassTypeId(),3);
+        getSelection().getSelectionEx(nullptr, App::DocumentObject::getClassTypeId(), Gui::ResolveMode::FollowLink);
 
     //test if selected object is a compound, and if it is, look how many children it has...
     std::size_t numShapes = 0;
@@ -561,7 +561,7 @@ void CmdPartFuse::activated(int iMsg)
 bool CmdPartFuse::isActive(void)
 {
     return getSelection().countObjectsOfType(
-            App::DocumentObject::getClassTypeId(),nullptr,3)>=1;
+            App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink) >= 1;
 }
 
 //===========================================================================
@@ -921,7 +921,7 @@ void CmdPartCompound::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
     unsigned int n = getSelection().countObjectsOfType(
-            App::DocumentObject::getClassTypeId(),nullptr,3);
+            App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink);
     if (n < 1) {
         QMessageBox::warning(Gui::getMainWindow(), QObject::tr("Wrong selection"),
             QObject::tr("Select one shape or more, please."));
@@ -954,7 +954,7 @@ void CmdPartCompound::activated(int iMsg)
 bool CmdPartCompound::isActive(void)
 {
     return getSelection().countObjectsOfType(
-            App::DocumentObject::getClassTypeId(),nullptr,3)>=1;
+            App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink) >= 1;
 }
 
 //===========================================================================
@@ -978,7 +978,7 @@ void CmdPartSection::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
     std::vector<Gui::SelectionObject> Sel = 
-        getSelection().getSelectionEx(nullptr, App::DocumentObject::getClassTypeId(),3);
+        getSelection().getSelectionEx(nullptr, App::DocumentObject::getClassTypeId(), Gui::ResolveMode::FollowLink);
     if (Sel.size() != 2) {
         QMessageBox::warning(Gui::getMainWindow(), QObject::tr("Wrong selection"),
             QObject::tr("Select two shapes please."));
@@ -1002,7 +1002,7 @@ void CmdPartSection::activated(int iMsg)
 
 bool CmdPartSection::isActive(void)
 {
-    return getSelection().countObjectsOfType(App::DocumentObject::getClassTypeId(),nullptr,3)==2;
+    return getSelection().countObjectsOfType(App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink) == 2;
 }
 
 //===========================================================================
@@ -1113,7 +1113,7 @@ void CmdPartExport::activated(int iMsg)
 
 bool CmdPartExport::isActive(void)
 {
-    return Gui::Selection().countObjectsOfType(App::DocumentObject::getClassTypeId(),nullptr,3) > 0;
+    return Gui::Selection().countObjectsOfType(App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink) > 0;
 }
 
 //===========================================================================
@@ -1185,7 +1185,7 @@ void CmdPartMakeSolid::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
     std::vector<App::DocumentObject*> objs = Gui::Selection().getObjectsOfType
-        (App::DocumentObject::getClassTypeId(),nullptr,3);
+        (App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink);
     runCommand(Doc, "import Part");
     for (std::vector<App::DocumentObject*>::iterator it = objs.begin(); it != objs.end(); ++it) {
         const TopoDS_Shape& shape = Part::Feature::getShape(*it);
@@ -1240,7 +1240,7 @@ void CmdPartMakeSolid::activated(int iMsg)
 bool CmdPartMakeSolid::isActive(void)
 {
     return Gui::Selection().countObjectsOfType
-        (App::DocumentObject::getClassTypeId(),nullptr,3) > 0;
+        (App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink) > 0;
 }
 
 //===========================================================================
@@ -1303,7 +1303,7 @@ void CmdPartReverseShape::activated(int iMsg)
 bool CmdPartReverseShape::isActive(void)
 {
     return Gui::Selection().countObjectsOfType
-        (Part::Feature::getClassTypeId(), 0, 3) > 0;
+        (Part::Feature::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink) > 0;
 }
 
 //===========================================================================
@@ -1385,7 +1385,7 @@ CmdPartMakeFace::CmdPartMakeFace()
 void CmdPartMakeFace::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
-    auto sketches = Gui::Selection().getObjectsOfType(App::DocumentObject::getClassTypeId(),nullptr,3);
+    auto sketches = Gui::Selection().getObjectsOfType(App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink);
     if(sketches.empty())
         return;
     openCommand(QT_TRANSLATE_NOOP("Command", "Make face"));
@@ -1413,7 +1413,7 @@ void CmdPartMakeFace::activated(int iMsg)
 
 bool CmdPartMakeFace::isActive(void)
 {
-    return (Gui::Selection().countObjectsOfType(App::DocumentObject::getClassTypeId(),nullptr,3) > 0 &&
+    return (Gui::Selection().countObjectsOfType(App::DocumentObject::getClassTypeId(), nullptr, Gui::ResolveMode::FollowLink) > 0 &&
             !Gui::Control().activeDialog());
 }
 
@@ -1960,7 +1960,7 @@ void CmdPartThickness::activated(int iMsg)
 bool CmdPartThickness::isActive(void)
 {
     Base::Type partid = Base::Type::fromName("Part::Feature");
-    bool objectsSelected = Gui::Selection().countObjectsOfType(partid, 0, 3) > 0;
+    bool objectsSelected = Gui::Selection().countObjectsOfType(partid, nullptr, Gui::ResolveMode::FollowLink) > 0;
     return (objectsSelected && !Gui::Control().activeDialog());
 }
 
diff --git a/src/Mod/Part/Gui/CommandSimple.cpp b/src/Mod/Part/Gui/CommandSimple.cpp
index ed73a27f9b..3393a2ee8f 100644
--- a/src/Mod/Part/Gui/CommandSimple.cpp
+++ b/src/Mod/Part/Gui/CommandSimple.cpp
@@ -189,12 +189,15 @@ CmdPartSimpleCopy::CmdPartSimpleCopy()
 static void _copyShape(const char *cmdName, bool resolve,bool needElement=false, bool refine=false) {
     Gui::WaitCursor wc;
     Gui::Command::openCommand(cmdName);
-    for(auto &sel : Gui::Selection().getSelectionEx("*",App::DocumentObject::getClassTypeId(),resolve)) {
+    for(auto &sel : Gui::Selection().getSelectionEx("*", App::DocumentObject::getClassTypeId(),
+                                                    resolve ? Gui::ResolveMode::OldStyleElement : Gui::ResolveMode::NoResolve)) {
         std::map<std::string,App::DocumentObject*> subMap;
         auto obj = sel.getObject();
-        if(!obj) continue;
-        if(resolve || !sel.hasSubNames())
+        if (!obj)
+            continue;
+        if (resolve || !sel.hasSubNames()) {
             subMap.emplace("",obj);
+        }
         else {
             for(const auto &sub : sel.getSubNames()) {
                 const char *element = nullptr;
@@ -215,8 +218,9 @@ static void _copyShape(const char *cmdName, bool resolve,bool needElement=false,
                     "App.ActiveDocument.addObject('Part::Feature','%s').Shape=__shape\n"
                     "App.ActiveDocument.ActiveObject.Label=%s.Label\n",
                         parentName.c_str(), v.first.c_str(),
-                        needElement?"True":"False", refine?"True":"False",
-                        needElement?".copy()":"", 
+                        needElement ? "True" : "False",
+                        refine ? "True" : "False",
+                        needElement ? ".copy()" : "",
                         v.second->getNameInDocument(), 
                         Gui::Command::getObjectCmd(v.second).c_str());
             auto newObj = App::GetApplication().getActiveDocument()->getActiveObject();
diff --git a/src/Mod/Part/Gui/TaskAttacher.cpp b/src/Mod/Part/Gui/TaskAttacher.cpp
index 9405a7e995..bb946d2183 100644
--- a/src/Mod/Part/Gui/TaskAttacher.cpp
+++ b/src/Mod/Part/Gui/TaskAttacher.cpp
@@ -366,7 +366,7 @@ void TaskAttacher::onSelectionChanged(const Gui::SelectionChanges& msg)
         std::vector<std::string> refnames = pcAttach->Support.getSubValues();
         App::DocumentObject* selObj = ViewProvider->getObject()->getDocument()->getObject(msg.pObjectName);
         if (!selObj || selObj == ViewProvider->getObject())//prevent self-referencing
-            return;
+            return;
         
         std::string subname = msg.pSubName;
 
@@ -564,7 +564,7 @@ void TaskAttacher::onRefName(const QString& text, unsigned idx)
         return;
 
     QLineEdit* line = getLine(idx);
-    if (line == nullptr)
+    if (line == nullptr)
         return;
 
     if (text.length() == 0) {
@@ -608,7 +608,7 @@ void TaskAttacher::onRefName(const QString& text, unsigned idx)
         parts.push_back(QString::fromLatin1(""));
     // Check whether this is the name of an App::Plane or Part::Datum feature
     App::DocumentObject* obj = ViewProvider->getObject()->getDocument()->getObject(parts[0].toLatin1());
-    if (obj == nullptr)
+    if (obj == nullptr)
         return;
 
     std::string subElement;
@@ -999,7 +999,7 @@ void TaskAttacher::visibilityAutomation(bool opening_not_closing)
         auto editDoc = Gui::Application::Instance->editDocument();
         App::DocumentObject *editObj = ViewProvider->getObject();
         std::string editSubName;
-        auto sels = Gui::Selection().getSelection(nullptr,0,true);
+        auto sels = Gui::Selection().getSelection(nullptr, Gui::ResolveMode::NoResolve, true);
         if(sels.size() && sels[0].pResolvedObject 
                        && sels[0].pResolvedObject->getLinkedObject()==editObj) 
         {
diff --git a/src/Mod/Part/Gui/TaskDimension.cpp b/src/Mod/Part/Gui/TaskDimension.cpp
index fd56514718..596d9d2332 100644
--- a/src/Mod/Part/Gui/TaskDimension.cpp
+++ b/src/Mod/Part/Gui/TaskDimension.cpp
@@ -121,7 +121,7 @@ bool PartGui::getShapeFromStrings(TopoDS_Shape &shapeOut, const std::string &doc
 
 bool PartGui::evaluateLinearPreSelection(TopoDS_Shape &shape1, TopoDS_Shape &shape2)
 {
-  std::vector<Gui::SelectionSingleton::SelObj> selections = Gui::Selection().getSelection(nullptr,false);
+  std::vector<Gui::SelectionSingleton::SelObj> selections = Gui::Selection().getSelection(nullptr, Gui::ResolveMode::NoResolve);
   if (selections.size() != 2)
     return false;
   std::vector<Gui::SelectionSingleton::SelObj>::iterator it;
@@ -515,7 +515,7 @@ void PartGui::DimensionLinear::setupDimension()
 }
 
 PartGui::TaskMeasureLinear::TaskMeasureLinear()
-    : Gui::SelectionObserver(true,false)
+    : Gui::SelectionObserver(true, Gui::ResolveMode::NoResolve)
     , selections1(), selections2(), buttonSelectedIndex(0)
 {
   setUpGui();
@@ -832,7 +832,7 @@ void PartGui::goDimensionAngularRoot()
 
 bool PartGui::evaluateAngularPreSelection(VectorAdapter &vector1Out, VectorAdapter &vector2Out)
 {
-  std::vector<Gui::SelectionSingleton::SelObj> selections = Gui::Selection().getSelection(nullptr,false);
+  std::vector<Gui::SelectionSingleton::SelObj> selections = Gui::Selection().getSelection(nullptr, Gui::ResolveMode::NoResolve);
   if (selections.size() > 4 || selections.size() < 2)
     return false;
   std::vector<Gui::SelectionSingleton::SelObj>::iterator it;
@@ -1514,7 +1514,7 @@ void PartGui::DimensionControl::clearAllSlot(bool)
 }
 
 PartGui::TaskMeasureAngular::TaskMeasureAngular()
-    : Gui::SelectionObserver(true,false)
+    : Gui::SelectionObserver(true, Gui::ResolveMode::NoResolve)
     , selections1(), selections2(), buttonSelectedIndex(0)
 {
   setUpGui();
diff --git a/src/Mod/PartDesign/Gui/Command.cpp b/src/Mod/PartDesign/Gui/Command.cpp
index 09be681a2e..59a9ff7b9c 100644
--- a/src/Mod/PartDesign/Gui/Command.cpp
+++ b/src/Mod/PartDesign/Gui/Command.cpp
@@ -355,7 +355,7 @@ void CmdPartDesignSubShapeBinder::activated(int iMsg)
     App::DocumentObject *parent = nullptr;
     std::string parentSub;
     std::map<App::DocumentObject *, std::vector<std::string> > values;
-    for (auto &sel : Gui::Selection().getCompleteSelection(0)) {
+    for (auto &sel : Gui::Selection().getCompleteSelection(Gui::ResolveMode::NoResolve)) {
         if (!sel.pObject) continue;
         auto &subs = values[sel.pObject];
         if (sel.SubName && sel.SubName[0])
diff --git a/src/Mod/PartDesign/Gui/ViewProviderShapeBinder.cpp b/src/Mod/PartDesign/Gui/ViewProviderShapeBinder.cpp
index 2234fee4da..887ca2d3a6 100644
--- a/src/Mod/PartDesign/Gui/ViewProviderShapeBinder.cpp
+++ b/src/Mod/PartDesign/Gui/ViewProviderShapeBinder.cpp
@@ -144,7 +144,7 @@ void ViewProviderShapeBinder::highlightReferences(const bool on, bool /*auxiliar
 
     PartGui::ViewProviderPart* svp = dynamic_cast<PartGui::ViewProviderPart*>(
         Gui::Application::Instance->getViewProvider(obj));
-    if (svp == nullptr)
+    if (svp == nullptr)
         return;
 
     if (on) {
@@ -271,7 +271,7 @@ std::string ViewProviderSubShapeBinder::dropObjectEx(App::DocumentObject* obj, A
     const char* subname, const std::vector<std::string>& elements)
 {
     auto self = dynamic_cast<PartDesign::SubShapeBinder*>(getObject());
-    if (!self)
+    if (!self)
         return std::string();
     std::map<App::DocumentObject*, std::vector<std::string> > values;
     if (!subname) subname = "";
@@ -356,7 +356,7 @@ void ViewProviderSubShapeBinder::updatePlacement(bool transaction) {
     App::DocumentObject* parent = nullptr;
     std::string parentSub;
     if (relative && self->getParents().size()) {
-        const auto& sel = Gui::Selection().getSelection("", 0);
+        const auto& sel = Gui::Selection().getSelection("", Gui::ResolveMode::NoResolve);
         if (sel.size() != 1 || !sel[0].pObject ||
             sel[0].pObject->getSubObject(sel[0].SubName) != self)
         {
diff --git a/src/Mod/TechDraw/Gui/Command.cpp b/src/Mod/TechDraw/Gui/Command.cpp
index 2cfe2c82e2..4eb58025bd 100644
--- a/src/Mod/TechDraw/Gui/Command.cpp
+++ b/src/Mod/TechDraw/Gui/Command.cpp
@@ -320,8 +320,8 @@ void CmdTechDrawView::activated(int iMsg)
     std::vector<App::DocumentObject*> xShapes;
     App::DocumentObject* partObj = nullptr;
     std::string faceName;
-    int resolve = 1;                                //mystery
-    bool single = false;                            //mystery
+    Gui::ResolveMode resolve = Gui::ResolveMode::OldStyleElement;  //mystery
+    bool single = false;                                           //mystery
     auto selection = getSelection().getSelectionEx(nullptr,
                                                    App::DocumentObject::getClassTypeId(),
                                                    resolve,
@@ -599,8 +599,8 @@ void CmdTechDrawProjectionGroup::activated(int iMsg)
     std::vector<App::DocumentObject*> xShapes;
     App::DocumentObject* partObj = nullptr;
     std::string faceName;
-    int resolve = 1;                                //mystery
-    bool single = false;                            //mystery
+    Gui::ResolveMode resolve = Gui::ResolveMode::OldStyleElement; //mystery
+    bool single = false;                                          //mystery
     auto selection = getSelection().getSelectionEx(nullptr,
                                                    App::DocumentObject::getClassTypeId(),
                                                    resolve,
diff --git a/src/Mod/TechDraw/Gui/CommandCreateDims.cpp b/src/Mod/TechDraw/Gui/CommandCreateDims.cpp
index 91c028608e..aa88bd4913 100644
--- a/src/Mod/TechDraw/Gui/CommandCreateDims.cpp
+++ b/src/Mod/TechDraw/Gui/CommandCreateDims.cpp
@@ -995,14 +995,13 @@ void CmdTechDrawLinkDimension::activated(int iMsg)
     if (!page) {
         return;
     }
-    std::string PageName = page->getNameInDocument();
 
     bool result = _checkSelection(this,2);
     if (!result)
         return;
 
     std::vector<Gui::SelectionObject> selection = getSelection().getSelectionEx(nullptr,
-            App::DocumentObject::getClassTypeId(),0);
+            App::DocumentObject::getClassTypeId(), Gui::ResolveMode::NoResolve);
 
     App::DocumentObject* obj3D = nullptr;
     std::vector<App::DocumentObject*> parts;