Redesign Collection's creator and notify mechanisms to be more generic

They now allow any functors, including lambdas.

diff --git a/source/collection.cpp b/source/collection.cpp
index c168d8abd002a5bd82134914a9ee9205a1ab06fb..8b295858ac72fadf42a535be78c7272d8e50ba27 100644 (file)
--- a/source/collection.cpp
+++ b/source/collection.cpp
@@ -21,7 +21,7 @@ void Collection::add_var(const string &name, const CollectionItemTypeBase *type,
 {
        insert_unique(items, name, var);
        if(type)
-               type->notify_item(*this, name, var);
+               type->notify_item(name, var);
 }
 
 const Variant &Collection::get_var(const string &name, const CollectionItemTypeBase *type)

diff --git a/source/collection.h b/source/collection.h
index 98b359e5eaedd28604a5d1f0a0085f470a657219..fb9470d591025e8beaa9377d7cd15fba2d4e5131 100644 (file)
--- a/source/collection.h
+++ b/source/collection.h
@@ -364,7 +364,7 @@ public:
        virtual bool can_create() const = 0;
        virtual void create_item(Collection &, const std::string &) const = 0;
        virtual void load_item(Collection &, Parser &, const std::string &) const = 0;
-       virtual void notify_item(Collection &, const std::string &, const Variant &) const = 0;
+       virtual void notify_item(const std::string &, const Variant &) const = 0;
 
        template<typename T>
        bool can_extract() const
@@ -394,46 +394,6 @@ template<typename T>
 class CollectionItemType: public CollectionItemTypeBase
 {
 private:
-       struct CreatorBase
-       {
-               virtual ~CreatorBase() { }
-
-               virtual T *create(Collection &, const std::string &) const = 0;
-       };
-
-       template<typename C>
-       struct Creator: CreatorBase
-       {
-               typedef T *(C::*FuncPtr)(const std::string &);
-
-               FuncPtr func;
-
-               Creator(FuncPtr f): func(f) { }
-
-               virtual T *create(Collection &coll, const std::string &name) const
-               { return (dynamic_cast<C &>(coll).*func)(name); }
-       };
-
-       struct NotifyeeBase
-       {
-               virtual ~NotifyeeBase() { }
-
-               virtual void notify(Collection &, const std::string &, T &) const = 0;
-       };
-
-       template<typename C>
-       struct Notifyee: NotifyeeBase
-       {
-               typedef void (C::*FuncPtr)(const std::string &, T &);
-
-               FuncPtr func;
-
-               Notifyee(FuncPtr f): func(f) { }
-
-               virtual void notify(Collection &coll, const std::string &name, T &item) const
-               { (dynamic_cast<C &>(coll).*func)(name, item); }
-       };
-
        template<typename B>
        struct Extractor: CollectionItemTypeBase::Extractor<B>
        {
@@ -441,21 +401,10 @@ private:
                { return *var.value<RefPtr<T> >(); }
        };
 
-       CreatorBase *creat;
-       std::vector<NotifyeeBase *> notif;
+       std::function<T *(const std::string &)> create_func;
+       std::vector<std::function<void(const std::string &, T &)>> notify_funcs;
 
 public:
-       CollectionItemType():
-               creat(0)
-       { }
-
-       ~CollectionItemType()
-       {
-               delete creat;
-               for(NotifyeeBase *n: notif)
-                       delete n;
-       }
-
        /** Sets a datafile keyword for this item type.  The Collection's loader
        will accept a statement with this keyword and a single string argument - the
        item's name. */
@@ -481,11 +430,10 @@ public:
        type.  It must return the created object, or null if it could not be
        created.  It's also permissible to load the item via other means and then
        return null. */
-       template<typename C>
-       CollectionItemType &creator(T *(C::*func)(const std::string &))
+       template<typename F>
+       CollectionItemType &creator(F func)
        {
-               delete creat;
-               creat = new Creator<C>(func);
+               create_func = func;
                return *this;
        }
 
@@ -497,10 +445,10 @@ public:
                return *this;
        }
 
-       template<typename C>
-       CollectionItemType &notify(void (C::*func)(const std::string &, T &))
+       template<typename F>
+       CollectionItemType &notify(F func)
        {
-               notif.push_back(new Notifyee<C>(func));
+               notify_funcs.emplace_back(func);
                return *this;
        }
 
@@ -514,13 +462,13 @@ public:
        { }
 
        virtual bool can_create() const
-       { return creat!=0; }
+       { return static_cast<bool>(create_func); }
 
        virtual void create_item(Collection &coll, const std::string &name) const
        {
-               if(!creat)
+               if(!create_func)
                        throw std::runtime_error("no creator");
-               T *obj = creat->create(coll, name);
+               T *obj = create_func(name);
                if(obj)
                        coll.add(name, obj);
        }
@@ -530,11 +478,11 @@ public:
                throw std::runtime_error("this type cannot be loaded");
        }
 
-       virtual void notify_item(Collection &coll, const std::string &name, const Variant &var) const
+       virtual void notify_item(const std::string &name, const Variant &var) const
        {
                RefPtr<T> obj = var.value<RefPtr<T> >();
-               for(NotifyeeBase *n: notif)
-                       n->notify(coll, name, *obj);
+               for(const auto &n: notify_funcs)
+                       n(name, *obj);
        }
 };