Gui: [skip ci] add method extensionSetupContextMenu to extension view provider

src/Gui/ViewProvider.cpp

@@ -649,6 +649,13 @@ bool ViewProvider::mouseButtonPressed(int button, bool pressed,
     return false;
 }
 
+void ViewProvider::setupContextMenu(QMenu* menu, QObject* receiver, const char* method)
+{
+    auto vector = getExtensionsDerivedFromType<Gui::ViewProviderExtension>();
+    for (Gui::ViewProviderExtension* ext : vector)
+        ext->extensionSetupContextMenu(menu, receiver, method);
+}
+
 bool ViewProvider::onDelete(const vector< string >& subNames)
 {
     bool del = true;

src/Gui/ViewProvider.h

@@ -458,7 +458,7 @@ public:
     virtual bool mouseButtonPressed(int button, bool pressed, const SbVec2s &cursorPos,
                                     const View3DInventorViewer* viewer);
     /// set up the context-menu with the supported edit modes
-    virtual void setupContextMenu(QMenu*, QObject*, const char*) {}
+    virtual void setupContextMenu(QMenu*, QObject*, const char*);
 
     /** @name direct handling methods
      *  This group of methods is to direct influence the

src/Gui/ViewProviderDragger.cpp

@@ -107,6 +107,7 @@ void ViewProviderDragger::setupContextMenu(QMenu* menu, QObject* receiver, const
 {
     QAction* act = menu->addAction(QObject::tr("Transform"), receiver, member);
     act->setData(QVariant((int)ViewProvider::Transform));
+    ViewProviderDocumentObject::setupContextMenu(menu, receiver, member);
 }
 
 ViewProvider *ViewProviderDragger::startEditing(int mode) {

src/Gui/ViewProviderExtension.h

@@ -89,6 +89,7 @@ public:
     virtual void extensionReattach(App::DocumentObject* ) { }
     virtual void extensionSetDisplayMode(const char* ) { }
     virtual std::vector<std::string> extensionGetDisplayModes(void) const {return std::vector<std::string>();}
+    virtual void extensionSetupContextMenu(QMenu*, QObject*, const char*) {}
 
     //update data of extended opject
     virtual void extensionUpdateData(const App::Property*);