handle now also section view, detail view and view

src/Mod/TechDraw/Gui/ViewProviderViewPart.h

@@ -60,6 +60,8 @@ public:
     virtual bool useNewSelectionModel(void) const {return false;}
     /// returns a list of all possible modes
     virtual std::vector<std::string> getDisplayModes(void) const;
+    virtual bool onDelete(const std::vector<std::string> &);
+    virtual bool canDelete(App::DocumentObject* obj) const;
 
 public:
     virtual void onChanged(const App::Property *prop);