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*/ |
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#ifndef UTIL_GENERICFACTORY_HPP |
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#define UTIL_GENERICFACTORY_HPP |
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#include <cassert> |
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#include <map> |
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#include <string> |
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#include <vector> |
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* @param Creator the callable entity that creates objects. This type must support operator(), |
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* taking no parameters and returning a pointer to Object. Default type is function pointer. |
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* |
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* Usage: |
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* @code |
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* //Shape class |
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* class Shape { |
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* } |
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* |
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* //register createLine |
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* ShapeFactory::getInstance()->registerCreator("Line", createLine); |
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* //note: must put ShapeFactory::getInstance()->registerCreator("Line", createLine) on the right |
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* //hand side, otherwise the compiler will consider it as a function declaration |
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* const bool registeredLine = ShapeFactory::getInstance()->registerCreator("Line", createLine); |
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* |
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* //Circle class |
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* class Circle : public Shape{ |
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* } |
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* |
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* //register createCircle |
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* ShapeFactory::getInstance()->registerCreator("Circle", createCircle); |
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* const bool registeredCircle = ShapeFactory::getInstance()->registerCreator("Circle", createCircle); |
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* |
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* //create object by ident |
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* Line* line = ShapeFactory::getInstance()->createObject("Line"); |
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* Circle* circle = ShapeFactory::getInstance()->createObject("Circle"); |
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* @endcode |
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* |
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* Or the user can use predefined macro DECLARE_CREATOR and REGISTER_CREATOR |
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* @code |
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* //Shape class |
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* class Shape { |
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* ... |
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* }; |
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* |
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* //instantiating a new object factory |
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* typedef GenericFactory<Shape> ShapeFactory; |
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* |
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* //Line class |
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* class Line : public Shape{ |
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* ... |
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* }; |
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* |
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* //declare function using macro |
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* DECLARE_CREATOR(Shape, Line) |
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* |
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* //register using macro |
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* REGISTER_CREATOR(ShapeFactory, "Line", Line); |
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|
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* //Circle class |
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* class Circle : public Shape{ |
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* ... |
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* }; |
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* |
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* //declare function using macro |
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* DECLARE_CREATOR(Shape, Circle) |
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* |
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* //register using macro |
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* REGISTER_CREATOR(ShapeFactory, "Circle", Circle); |
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* @endcode |
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*/ |
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template<class Object, typename IdentType = std::string, typename Creator = Object* (*)()> |
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class GenericFactory { |
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* corresponding creator for the type identifier and returns its result. |
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* @return a pointer of the concrete object, return NULL if no creator is registed for |
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* creating this concrete object |
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* @id the identification of the concrete object |
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* @param id the identification of the concrete object |
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*/ |
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Object* createObject(const IdentType& id) { |
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typename CreatorMapType::iterator i = creatorMap_.find(id); |
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if (i != creatorMap_.end()) { |
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//invoke functor to create object |
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return (i->second)(); |
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} else { |
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return NULL; |
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CreatorMapType creatorMap_; |
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}; |
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|
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/** write out all of the type identifier to a output stream */ |
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/** write out all of the type identifiers to an output stream */ |
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template<typename O, typename I, typename C> |
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std::ostream& operator <<(std::ostream& o, GenericFactory<O, I, C>& factory) { |
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std::vector<I> idents; |
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template<class Object, typename IdentType,typename Creator> |
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GenericFactory<Object,IdentType,Creator>* GenericFactory<Object,IdentType,Creator>::instance_ ; |
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|
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|
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#define DECLARE_CREATOR(abstractObject, concreteObject) \ |
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abstractObject* create##concreteObject(){\ |
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inline abstractObject* create##concreteObject(){\ |
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return new concreteObject;\ |
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} |
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|
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#define REGISTER_CREATOR(factory, ident, concreteObject) \ |
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const bool registered##concreteObject = factory::getInstance()->registerCreator(ident, create##concreteObject); |
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|
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|
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}//namespace oopse |
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#endif //UTIL_GENERICFACTORY_HPP |
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