Separate subclass ToolbarMenuVisitor from MenuVisitor

src/Menus.cpp

@@ -199,7 +199,7 @@ namespace MenuTable {
 
 MenuItem::MenuItem( const Identifier &internalName,
    const TranslatableString &title_, BaseItemPtrs &&items_ )
-: ConcreteGroupItem< false, MenuVisitor >{
+: ConcreteGroupItem< false, ToolbarMenuVisitor >{
    internalName, std::move( items_ ) }, title{ title_ }
 {
    wxASSERT( !title.empty() );
@@ -208,7 +208,7 @@ MenuItem::~MenuItem() {}
 
 ConditionalGroupItem::ConditionalGroupItem(
    const Identifier &internalName, Condition condition_, BaseItemPtrs &&items_ )
-: ConcreteGroupItem< false, MenuVisitor >{
+: ConcreteGroupItem< false, ToolbarMenuVisitor >{
    internalName, std::move( items_ ) }, condition{ condition_ }
 {
 }
@@ -240,6 +240,8 @@ CommandGroupItem::~CommandGroupItem() {}
 
 SpecialItem::~SpecialItem() {}
 
+MenuSection::~MenuSection() {}
+
 CommandHandlerFinder FinderScope::sFinder =
    [](AudacityProject &project) -> CommandHandlerObject & {
       // If this default finder function is reached, then FinderScope should
@@ -1058,10 +1060,10 @@ namespace {
 
 using namespace MenuTable;
 
-struct MenuItemVisitor : MenuVisitor
+struct MenuItemVisitor : ToolbarMenuVisitor
 {
    MenuItemVisitor( AudacityProject &proj, CommandManager &man )
-      : MenuVisitor(proj), manager( man ) {}
+      : ToolbarMenuVisitor(proj), manager( man ) {}
 
    void DoBeginGroup( GroupItem &item, const Path& ) override
    {
@@ -1209,7 +1211,7 @@ void MenuCreator::CreateMenusAndCommands(AudacityProject &project)
 #endif
 }
 
-void MenuManager::Visit( MenuVisitor &visitor )
+void MenuManager::Visit( ToolbarMenuVisitor &visitor )
 {
    static const auto menuTree = MenuTable::Items( MenuPathStart );
    Registry::Visit( visitor, menuTree.get(), &sRegistry() );

src/Menus.h

@@ -54,7 +54,7 @@ public:
    PluginID mLastEffect{};
 };
 
-struct MenuVisitor;
+struct ToolbarMenuVisitor;
 
 class MenuManager final
    : public MenuCreator
@@ -72,7 +72,7 @@ public:
    MenuManager &operator=( const MenuManager & ) PROHIBITED;
    ~MenuManager();
 
-   static void Visit( MenuVisitor &visitor );
+   static void Visit( ToolbarMenuVisitor &visitor );
 
    static void ModifyUndoMenuItems(AudacityProject &project);
    static void ModifyToolbarMenus(AudacityProject &project);

src/commands/CommandManager.h

@@ -667,9 +667,6 @@ namespace Registry {
 
 struct MenuVisitor : Registry::Visitor
 {
-   explicit MenuVisitor( AudacityProject &p ) : project{ p } {}
-   operator AudacityProject & () const { return project; }
-
    // final overrides
    void BeginGroup( Registry::GroupItem &item, const Path &path ) final;
    void EndGroup( Registry::GroupItem &item, const Path& ) final;
@@ -681,20 +678,25 @@ struct MenuVisitor : Registry::Visitor
    virtual void DoVisit( Registry::SingleItem &item, const Path &path );
    virtual void DoSeparator();
 
-   AudacityProject &project;
-
 private:
    void MaybeDoSeparator();
    std::vector<bool> firstItem;
    std::vector<bool> needSeparator;
 };
 
+struct ToolbarMenuVisitor : MenuVisitor
+{
+   explicit ToolbarMenuVisitor( AudacityProject &p ) : project{ p } {}
+   operator AudacityProject & () const { return project; }
+   AudacityProject &project;
+};
+
 // Define items that populate tables that specifically describe menu trees
 namespace MenuTable {
    using namespace Registry;
 
    // Describes a main menu in the toolbar, or a sub-menu
-   struct MenuItem final : ConcreteGroupItem< false, MenuVisitor > {
+   struct MenuItem final : ConcreteGroupItem< false, ToolbarMenuVisitor > {
       // Construction from an internal name and a previously built-up
       // vector of pointers
       MenuItem( const Identifier &internalName,
@@ -703,7 +705,7 @@ namespace MenuTable {
       template< typename... Args >
          MenuItem( const Identifier &internalName,
             const TranslatableString &title_, Args&&... args )
-            : ConcreteGroupItem< false, MenuVisitor >{
+            : ConcreteGroupItem< false, ToolbarMenuVisitor >{
                internalName, std::forward<Args>(args)... }
             , title{ title_ }
          {}
@@ -714,7 +716,8 @@ namespace MenuTable {
 
    // Collects other items that are conditionally shown or hidden, but are
    // always available to macro programming
-   struct ConditionalGroupItem final : ConcreteGroupItem< false, MenuVisitor > {
+   struct ConditionalGroupItem final
+      : ConcreteGroupItem< false, ToolbarMenuVisitor > {
       using Condition = std::function< bool() >;
 
       // Construction from an internal name and a previously built-up
@@ -725,7 +728,7 @@ namespace MenuTable {
       template< typename... Args >
          ConditionalGroupItem( const Identifier &internalName,
             Condition condition_, Args&&... args )
-            : ConcreteGroupItem< false, MenuVisitor >{
+            : ConcreteGroupItem< false, ToolbarMenuVisitor >{
                internalName, std::forward<Args>(args)... }
             , condition{ condition_ }
          {}
@@ -839,18 +842,21 @@ namespace MenuTable {
       Appender fn;
    };
 
-   template< bool Transparent >
+   // This exists only so that dynamic_cast can find it
-   struct MenuPart : ConcreteGroupItem< Transparent, MenuVisitor >
+   struct MenuSection {
+      virtual ~MenuSection();
+   };
+
+   struct MenuPart : ConcreteGroupItem< false, ToolbarMenuVisitor >, MenuSection
    {
       template< typename... Args >
       explicit
       MenuPart( const Identifier &internalName, Args&&... args )
-         : ConcreteGroupItem< Transparent, MenuVisitor >{
+         : ConcreteGroupItem< false, ToolbarMenuVisitor >{
             internalName, std::forward< Args >( args )... }
       {}
    };
-   using MenuItems = MenuPart< true >;
+   using MenuItems = ConcreteGroupItem< true, ToolbarMenuVisitor >;
-   using MenuSection = MenuPart< false >;
 
    // The following, and Shared(), are the functions to use directly
    // in writing table definitions.
@@ -874,9 +880,9 @@ namespace MenuTable {
    // It's not necessary that the sisters of sections be other sections, but it
    // might clarify the logical groupings.
    template< typename... Args >
-   inline std::unique_ptr< MenuSection > Section(
+   inline std::unique_ptr< MenuPart > Section(
       const Identifier &internalName, Args&&... args )
-         { return std::make_unique< MenuSection >(
+         { return std::make_unique< MenuPart >(
             internalName, std::forward<Args>(args)... ); }
    
    // Menu items can be constructed two ways, as for group items

src/menus/HelpMenus.cpp

@@ -380,9 +380,9 @@ void OnMenuTree(const CommandContext &context)
    auto &project = context.project;
    
    using namespace MenuTable;
-   struct MyVisitor : MenuVisitor
+   struct MyVisitor : ToolbarMenuVisitor
    {
-      using MenuVisitor::MenuVisitor;
+      using ToolbarMenuVisitor::ToolbarMenuVisitor;
 
       enum : unsigned { TAB = 3 };
       void DoBeginGroup( GroupItem &item, const Path& ) override