Delete DPGI's when parent DPG deleted

Ensure Gui/QGIVxx is removed when App/DVxxxx is deleted

src/Mod/TechDraw/App/DrawProjGroup.cpp

@@ -176,7 +176,9 @@ void DrawProjGroup::onChanged(const App::Property* prop)
     TechDraw::DrawPage *page = getPage();
     if (!isRestoring() && page) {
         if ( prop == &Views ) {
-            recompute();
+            if (!isDeleting()) {
+                recompute();  
+            }
         } else if (prop == &Scale) {
             updateChildren(Scale.getValue());
             //resetPositions();
@@ -808,7 +810,9 @@ TechDraw::DrawProjGroupItem* DrawProjGroup::getAnchor(void)
     App::DocumentObject* docObj = Anchor.getValue();
     if (docObj == nullptr) {
         //explode! DPG w/o anchor
-        Base::Console().Error("Error - DPG::getAnchor - DPG has no Anchor!!!\n");
+        if (!isDeleting()) {
+            Base::Console().Error("Error - DPG::getAnchor - DPG has no Anchor!!!\n");
+        }
     } else {
         result = static_cast<DrawProjGroupItem*>(docObj);
     }

src/Mod/TechDraw/App/DrawProjGroupItem.cpp

@@ -164,13 +164,15 @@ void DrawProjGroupItem::unsetupObject()
 {
     if (getGroup() != nullptr) {
         if (getGroup()->hasProjection(Type.getValueAsString()) ) {
-            if (getGroup()->getAnchor() == this) {
+            if ((getGroup()->getAnchor() == this) &&
+                 !getGroup()->isDeleting() )         {
                    Base::Console().Warning("Warning - DPG (%s/%s) may be corrupt - Anchor deleted\n",
                                            getGroup()->getNameInDocument(),getGroup()->Label.getValue());
                    getGroup()->Anchor.setValue(nullptr);
              }
         }
     }
+    DrawViewPart::unsetupObject();
 }
 
 PyObject *DrawProjGroupItem::getPyObject(void)

src/Mod/TechDraw/App/DrawViewCollection.cpp

@@ -26,6 +26,8 @@
 # include <sstream>
 #endif
 
+#include <App/Document.h>
+
 #include <Base/Console.h>
 #include <Base/Exception.h>
 
@@ -42,6 +44,7 @@ PROPERTY_SOURCE(TechDraw::DrawViewCollection, TechDraw::DrawView)
 
 DrawViewCollection::DrawViewCollection()
 {
+    nowDeleting = false;
     static const char *group = "Drawing view";
     ADD_PROPERTY_TYPE(Source    ,(0), group, App::Prop_None,"Shape to view");
     ADD_PROPERTY_TYPE(Views     ,(0), group, App::Prop_None,"Attached Views");
@@ -165,6 +168,26 @@ void DrawViewCollection::onChanged(const App::Property* prop)
     TechDraw::DrawView::onChanged(prop);
 }
 
+void DrawViewCollection::unsetupObject()
+{
+    nowDeleting = true;
+
+    // Remove the collection's views from document
+    App::Document* doc = getDocument();
+    std::string docName = doc->getName();
+
+    const std::vector<App::DocumentObject*> currViews = Views.getValues();
+    std::vector<App::DocumentObject*> emptyViews;
+    std::vector<App::DocumentObject*>::const_iterator it = currViews.begin();
+    for (; it != currViews.end(); it++) {
+        std::string viewName = (*it)->getNameInDocument();
+        Base::Interpreter().runStringArg("App.getDocument(\"%s\").removeObject(\"%s\")",
+                                          docName.c_str(), viewName.c_str());
+    }
+    Views.setValues(emptyViews);
+}
+
+
 App::DocumentObjectExecReturn *DrawViewCollection::execute(void)
 {
     if (ScaleType.isValue("Page")) {

src/Mod/TechDraw/App/DrawViewCollection.h

@@ -50,14 +50,13 @@ public:
     int addView(DrawView *view);
     int removeView(DrawView *view);
     void rebuildViewList(void);
+    bool isDeleting(void) { return nowDeleting; }
 
     int countChildren();
-    /** @name methods overide Feature */
-    //@{
-    /// recalculate the Feature
+
     virtual void onDocumentRestored();
     virtual App::DocumentObjectExecReturn *execute(void);
-    //@}
+    virtual void unsetupObject();
 
     /// returns the type name of the ViewProvider
     virtual const char* getViewProviderName(void) const {
@@ -67,6 +66,7 @@ public:
 
 protected:
     void onChanged(const App::Property* prop);
+    bool nowDeleting;
 };
 
 } //namespace TechDraw