[TD] Landmark Dim minor clean ups

- clean up reference vertices on delete

- protect fail on close empty Page

- hide unimplemented functions

src/Mod/TechDraw/App/DrawViewPart.cpp

@@ -335,6 +335,9 @@ void DrawViewPart::partExec(TopoDS_Shape shape)
 {
 //    Base::Console().Message("DVP::partExec()\n");
     geometryObject = makeGeometryForShape(shape);
+    if (geometryObject == nullptr) {
+        return;
+    }
 
 #if MOD_TECHDRAW_HANDLE_FACES
 //    auto start = std::chrono::high_resolution_clock::now();
@@ -347,7 +350,7 @@ void DrawViewPart::partExec(TopoDS_Shape shape)
         }
     }
 #endif //#if MOD_TECHDRAW_HANDLE_FACES
-    std::vector<TechDraw::Vertex*> verts = getVertexGeometry();
+//    std::vector<TechDraw::Vertex*> verts = getVertexGeometry();
     addCosmeticVertexesToGeom();
     addCosmeticEdgesToGeom();
     addCenterLinesToGeom();
@@ -486,6 +489,9 @@ TechDraw::GeometryObject* DrawViewPart::buildGeometryObject(TopoDS_Shape shape,
 //! make faces from the existing edge geometry
 void DrawViewPart::extractFaces()
 {
+    if (geometryObject == nullptr) {
+        return;
+    }
     geometryObject->clearFaceGeom();
     const std::vector<TechDraw::BaseGeom*>& goEdges =
                        geometryObject->getVisibleFaceEdges(SmoothVisible.getValue(),SeamVisible.getValue());
@@ -668,18 +674,29 @@ std::vector<TechDraw::DrawViewBalloon*> DrawViewPart::getBalloons() const
 
 const std::vector<TechDraw::Vertex *> DrawViewPart::getVertexGeometry() const
 {
-    std::vector<TechDraw::Vertex*> gVerts = geometryObject->getVertexGeometry();
-    return gVerts;
+    std::vector<TechDraw::Vertex *> result;
+    if (geometryObject != nullptr) {
+        result = geometryObject->getVertexGeometry();
+    }
+    return result;
 }
 
-const std::vector<TechDraw::Face *> & DrawViewPart::getFaceGeometry() const
+const std::vector<TechDraw::Face *> DrawViewPart::getFaceGeometry() const
 {
-    return geometryObject->getFaceGeometry();
+    std::vector<TechDraw::Face*> result;
+    if (geometryObject != nullptr) {
+        result = geometryObject->getFaceGeometry();
+    }
+    return result;
 }
 
-const std::vector<TechDraw::BaseGeom  *> & DrawViewPart::getEdgeGeometry() const
+const std::vector<TechDraw::BaseGeom*> DrawViewPart::getEdgeGeometry() const
 {
-    return geometryObject->getEdgeGeometry();
+    std::vector<TechDraw::BaseGeom  *> result;
+    if (geometryObject != nullptr) {
+        result = geometryObject->getEdgeGeometry();
+    }
+    return result;
 }
 
 //! returns existing BaseGeom of 2D Edge(idx)
@@ -1113,20 +1130,23 @@ void DrawViewPart::removeReferenceVertex(std::string tag)
 //            delete v;  //??? who deletes v?
         }
     }
+    m_referenceVerts = newRefVerts;
     resetReferenceVerts();  
 }
 
 void DrawViewPart::removeAllReferencesFromGeom()
 {
 //    Base::Console().Message("DVP::removeAllReferencesFromGeom()\n");
-    std::vector<TechDraw::Vertex *> gVerts = getVertexGeometry();
-    std::vector<TechDraw::Vertex *> newVerts;
-    for (auto& gv: gVerts) {
-        if (!gv->reference) {
-            newVerts.push_back(gv);
+    if (!m_referenceVerts.empty()) {
+        std::vector<TechDraw::Vertex *> gVerts = getVertexGeometry();
+        std::vector<TechDraw::Vertex *> newVerts;
+        for (auto& gv: gVerts) {
+            if (!gv->reference) {
+                newVerts.push_back(gv);
+            }
         }
+        getGeometryObject()->setVertexGeometry(newVerts);
     }
-    getGeometryObject()->setVertexGeometry(newVerts);
 }
 
 void DrawViewPart::resetReferenceVerts()

src/Mod/TechDraw/App/DrawViewPart.h

@@ -124,10 +124,10 @@ class TechDrawExport DrawViewPart : public DrawView, public CosmeticExtension
     std::vector<TechDraw::DrawViewDimension*> getDimensions() const;
     std::vector<TechDraw::DrawViewBalloon*> getBalloons() const;
 
-    const std::vector<TechDraw::Vertex *> getVertexGeometry() const;
-    const std::vector<TechDraw::BaseGeom  *> & getEdgeGeometry() const;
-    const std::vector<TechDraw::BaseGeom  *> getVisibleFaceEdges() const;
-    const std::vector<TechDraw::Face *> & getFaceGeometry() const;
+    const std::vector<TechDraw::Vertex*> getVertexGeometry() const;
+    const std::vector<TechDraw::BaseGeom*> getEdgeGeometry() const;
+    const std::vector<TechDraw::BaseGeom*> getVisibleFaceEdges() const;
+    const std::vector<TechDraw::Face*> getFaceGeometry() const;
 
     bool hasGeometry(void) const;
     TechDraw::GeometryObject* getGeometryObject(void) const { return geometryObject; }

src/Mod/TechDraw/App/LandmarkDimension.cpp

@@ -115,7 +115,7 @@ App::DocumentObjectExecReturn *LandmarkDimension::execute(void)
 
     std::vector<DocumentObject*> features = References3D.getValues();
     //if distance, required size = 2
-    //if angle, required size = 3;
+    //if angle, required size = 3;    //not implemented yet
     unsigned int requiredSize = 2;
     if (features.size() < requiredSize) {
         return App::DocumentObject::StdReturn;
@@ -147,7 +147,7 @@ App::DocumentObjectExecReturn *LandmarkDimension::execute(void)
     m_linearPoints.first = points.front();
     m_linearPoints.second = points.back();
 
-    //m_anglePoints.first = 
+    //m_anglePoints.first =                  //not implemented yet
 
     App::DocumentObjectExecReturn* dvdResult = DrawViewDimension::execute();
 
@@ -258,6 +258,23 @@ void LandmarkDimension::onDocumentRestored()
     DrawViewDimension::onDocumentRestored();
 }
 
+void LandmarkDimension::unsetupObject()
+{
+
+//    bool isRemoving = testStatus(App::ObjectStatus::Remove);
+//    Base::Console().Message("LD::unsetupObject - isRemove: %d status: %X\n",
+//                            isRemoving, getStatus());
+    TechDraw::DrawViewPart* dvp = getViewPart();
+
+    std::vector<std::string> tags = ReferenceTags.getValues();
+    for (auto& t: tags) {
+        dvp->removeReferenceVertex(t);
+    }
+    dvp->resetReferenceVerts();
+    dvp->requestPaint();
+}
+
+
 //??? why does getPyObject work sometimes and no others???
 //PyObject *LandmarkDimension::getPyObject(void)
 //{

src/Mod/TechDraw/App/LandmarkDimension.h

@@ -52,6 +52,8 @@ class TechDrawExport LandmarkDimension : public TechDraw::DrawViewDimension
 
     virtual App::DocumentObjectExecReturn *execute(void) override;
     short mustExecute() const override;
+    virtual void unsetupObject() override;
+
     virtual const char* getViewProviderName(void) const override {
         return "TechDrawGui::ViewProviderDimension"; }
 /*    virtual PyObject *getPyObject(void) override;*/

src/Mod/TechDraw/Gui/CommandCreateDims.cpp

@@ -1360,24 +1360,23 @@ CmdTechDrawLandmarkDimension::CmdTechDrawLandmarkDimension()
 void CmdTechDrawLandmarkDimension::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
-    bool result = _checkSelection(this,3);  //redundant??
+    bool result = _checkSelection(this,3);
     if (!result)
         return;
 
     const std::vector<App::DocumentObject*> objects = getSelection().
                                         getObjectsOfType(Part::Feature::getClassTypeId());  //??
-    if ( (objects.size() != 2) &&
-         (objects.size() != 3) ) {
+    if (objects.size() != 2) {
         QMessageBox::warning(Gui::getMainWindow(), QObject::tr("Wrong selection"),
-            QObject::tr("Select 2 or 3 point objects and 1 View. (1)"));
+            QObject::tr("Select 2 point objects and 1 View. (1)"));
         return;
     }
 
     const std::vector<App::DocumentObject*> views = getSelection().
                                         getObjectsOfType(TechDraw::DrawViewPart::getClassTypeId());
     if (views.size() != 1) {
         QMessageBox::warning(Gui::getMainWindow(), QObject::tr("Wrong selection"),
-            QObject::tr("Select 2 or 3 two point objects and 1 View. (2)"));
+            QObject::tr("Select 2 point objects and 1 View. (2)"));
         return;
     }
 
@@ -1403,13 +1402,16 @@ void CmdTechDrawLandmarkDimension::activated(int iMsg)
         doCommand(Doc,"App.activeDocument().%s.Type = '%s'",FeatName.c_str(), "Distance");
         refs2d.push_back(dvp);
         refs2d.push_back(dvp);
-    } else if (objects.size() == 3) {
-        doCommand(Doc,"App.activeDocument().%s.Type = '%s'",FeatName.c_str(), "Angle3Pt");
-        refs2d.push_back(dvp);
-        refs2d.push_back(dvp);
-        refs2d.push_back(dvp);
-        subs.push_back("Vertex1");
     }
+//    } else if (objects.size() == 3) {             //not implemented yet
+//        doCommand(Doc,"App.activeDocument().%s.Type = '%s'",FeatName.c_str(), "Angle3Pt");
+//        refs2d.push_back(dvp);
+//        refs2d.push_back(dvp);
+//        refs2d.push_back(dvp);
+//        //subs.push_back("Vertex1");
+//        //subs.push_back("Vertex1");
+//        //subs.push_back("Vertex1");
+//    }
 
     dim = dynamic_cast<TechDraw::LandmarkDimension *>(getDocument()->getObject(FeatName.c_str()));
     if (!dim) {