Simplify loading collection items

The ItemLoader wrapper from DirectoryCollection can be used in the base
Collection::Loader as well.  This removes the need for the kludgy struct
Add and the need for two separate loader functions.  As an added bonus,
the ItemLoader can still be used in DirectoryCollection and future derived
classes as well, further reducing duplication.

diff --git a/source/collection.h b/source/collection.h
index b2c91d6879c82ef486b9b29b78f0f4054779dd59..3d5b7f0a6abce95bc8aa5d6ec05749be3ec6f8b2 100644 (file)
--- a/source/collection.h
+++ b/source/collection.h
@@ -55,34 +55,27 @@ public:
                template<typename T> friend class CollectionItemType;
 
        private:
-               template<typename T, typename S, bool = NeedsCollection<typename T::Loader>::value>
-               struct Add;
-
                Collection &coll;
 
        public:
                Loader(Collection &);
                Collection &get_object() const { return coll; }
        private:
-               template<typename T, typename S, typename C>
-               void coll_item(const std::string &n)
-               {
-                       RefPtr<T> it = new T;
-                       load_sub(*it, dynamic_cast<C &>(coll));
-                       coll.add<S>(n, it.get());
-                       it.release();
-               }
-
                template<typename T, typename S>
                void item(const std::string &n)
                {
                        RefPtr<T> it = new T;
-                       load_sub(*it);
+                       ItemLoader<T> ldr(*it, coll);
+                       load_sub_with(ldr);
                        coll.add<S>(n, it.get());
                        it.release();
                }
        };
 
+protected:
+       template<typename T, bool = NeedsCollection<typename T::Loader>::value>
+       class ItemLoader;
+
 private:
        typedef std::map<std::string, Variant> ItemMap;
        typedef std::list<CollectionItemTypeBase *> TypeList;
@@ -272,19 +265,22 @@ protected:
        CollectionItemType<T> &add_type();
 };
 
-
-template<typename T, typename S>
-struct Collection::Loader::Add<T, S, false>
+template<typename T>
+class Collection::ItemLoader<T, false>: public T::Loader
 {
-       static void add(Loader &loader, const std::string &kwd)
-       { loader.add(kwd, &Loader::item<T, S>); }
+public:
+       ItemLoader(T &o, Collection &):
+               T::Loader(o)
+       { }
 };
 
-template<typename T, typename S>
-struct Collection::Loader::Add<T, S, true>
+template<typename T>
+class Collection::ItemLoader<T, true>: public T::Loader
 {
-       static void add(Loader &loader, const std::string &kwd)
-       { loader.add(kwd, &Loader::coll_item<T, S, typename T::Loader::Collection>); }
+public:
+       ItemLoader(T &o, Collection &c):
+               T::Loader(o, dynamic_cast<typename T::Loader::Collection &>(c))
+       { }
 };
 
 
@@ -383,7 +379,7 @@ private:
                { return RefPtr<S>(0); }
 
                virtual void add_to_loader(Collection::Loader &loader, const std::string &kwd)
-               { Collection::Loader::Add<T, S>::add(loader, kwd); }
+               { loader.add(kwd, &Collection::Loader::item<T, S>); }
        };
 
        CreatorBase *creat;

diff --git a/source/directorycollection.h b/source/directorycollection.h
index cbaffd65532d048735edabaef6610533ced96c01..a796054b43569d4892e919ec5a337c4daba25409 100644 (file)
--- a/source/directorycollection.h
+++ b/source/directorycollection.h
@@ -13,9 +13,6 @@ A Collection that can automatically load items from files in a directory.
 class DirectoryCollection: public Collection
 {
 private:
-       template<typename T, bool = NeedsCollection<typename T::Loader>::value>
-       class ItemLoader;
-
        std::list<FS::Path> dirs;
 
 public:
@@ -57,24 +54,6 @@ protected:
        bool lookup_file(const std::string &, FS::Path &) const;
 };
 
-template<typename T>
-class DirectoryCollection::ItemLoader<T, false>: public T::Loader
-{
-public:
-       ItemLoader(T &o, Collection &):
-               T::Loader(o)
-       { }
-};
-
-template<typename T>
-class DirectoryCollection::ItemLoader<T, true>: public T::Loader
-{
-public:
-       ItemLoader(T &o, Collection &c):
-               T::Loader(o, dynamic_cast<typename T::Loader::Collection &>(c))
-       { }
-};
-
 } // namespace DataFile
 } // namespace Msp