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*/ |
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/** |
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* @file Vector3.hpp |
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* @file GenericFactory.hpp |
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* @author Teng Lin |
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* @date 09/14/2004 |
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* @date 10/24/2004 |
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* @version 1.0 |
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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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|
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namespace oopse { |
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template<class Product, typename ProductIdentType = std::string, typename Creator = Product* (*)() > |
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class GenericFactory{ |
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|
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/** |
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* @class GenericFactory GenericFactory.hpp "utils/GenericFactory.hpp" |
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* @brief GenericFactory is a template based Object Factory |
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* Factory pattern is used to define an interface for creating an object. |
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* |
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* @param Object the base class of the hierarchy for which you provide the object factory. |
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* @param IdentType the object that identifies the type of the concrete object. Default type is string |
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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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* |
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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 to create Line |
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* Shape* createLine() { |
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* return new Line; |
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* } |
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* |
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* //register 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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* |
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* //declare function to create Circle |
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* Shape* createCircle() { |
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* return new Circle; |
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* } |
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* |
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* //register 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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public: |
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typedef GenericFactory<Object, IdentType, Creator> FactoryType; |
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typedef std::map<IdentType, Creator> CreatorMapType; |
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|
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typedef std::map<ProductIdentType, Creator*> CreatorMapType; |
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typedef GenericFactory<Product, ProductIdentType, Creator> SelfType; |
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static SelfType* getInstance() { |
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if (instance_ == NULL) { |
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instance_ = new GenericFactory<Product, ProductIdentType, Creator>(); |
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} |
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|
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/** |
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* Returns an instance of object factory |
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* @return an instance of object factory |
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*/ |
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static FactoryType* getInstance(){ |
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if (instance_ == NULL) |
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instance_ = new FactoryType; |
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return instance_; |
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} |
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|
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//bool register( const ProductIdentType& id, Creator creator) { |
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|
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//insert method in std::map will return a pair<iterator, bool>. the second |
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//element of this pair indicates whether the result of the operation |
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//return creatorMap_.insert(CreatorMapType::value_type(id, creator)).second; |
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//} |
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/** |
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* Registers a creator with a type identifier |
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* @return true if registration is succeed, otherwise return false |
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* @id the identification of the concrete object |
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* @creator the object responsible to create the concrete object |
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*/ |
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bool registerCreator(const IdentType& id, Creator creator) { |
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return creatorMap_.insert( |
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CreatorMapType::value_type(id, creator)).second; |
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} |
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|
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bool unregister(const ProductIdentType& id) { |
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|
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return creatorMap_->erase(id) == 1; |
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|
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/** |
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* Unregisters the creator for the given type identifier. If the type identifier |
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* was previously registered, the function returns true. |
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* @return truethe type identifier was previously registered and the creator is removed, |
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* otherwise return false |
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* @id the identification of the concrete object |
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*/ |
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bool unregisterCreator(const IdentType& id) { |
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return creatorMap_.erase(id) == 1; |
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} |
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|
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bool hasCreator( const ProductIdentType& id ) { |
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CreatorMapType::iterator i; |
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|
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i = creatorMap_.find(id); |
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|
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/** |
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* Looks up the type identifier in the internal map. If it is found, it invokes the |
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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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> |
* @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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return true; |
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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 false; |
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> |
return NULL; |
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} |
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} |
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|
|
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//const std::string toString() { |
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> |
/** |
| 183 |
> |
* Returns all of the registed type identifiers |
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> |
* @return all of the registed type identifiers |
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> |
*/ |
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> |
std::vector<IdentType> getIdents() { |
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> |
std::vector<IdentType> idents; |
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typename CreatorMapType::iterator i; |
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|
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< |
|
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< |
//} |
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|
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Product* createProduct( const ProductIdentType& id ) { |
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CreatorMapType::iterator i; |
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|
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i = creatorMap_.find(id); |
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|
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< |
if (i != creatorMap_.end()) { |
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< |
//call the function to create the product |
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< |
return (i->second)(); |
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} else { |
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return NULL; |
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> |
for (i = creatorMap_.begin(); i != creatorMap_.end(); ++i) { |
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> |
idents.push_back(i->first); |
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} |
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+ |
|
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+ |
return idents; |
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} |
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< |
|
| 197 |
< |
private: |
| 198 |
< |
GenericFactory(){} |
| 96 |
< |
static SelfType* instance_; |
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> |
|
| 197 |
> |
public: |
| 198 |
> |
static FactoryType* instance_; |
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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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+ |
template<typename O, typename I, typename C> |
| 204 |
+ |
std::ostream& operator <<(std::ostream& o, GenericFactory<O, I, C>& factory) { |
| 205 |
+ |
std::vector<I> idents; |
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+ |
std::vector<I>::iterator i; |
| 207 |
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|
| 208 |
< |
#define REGISTER_CREATOR(factory, product, id) \ |
| 209 |
< |
product * create##product() {\ |
| 210 |
< |
return new product(); \ |
| 208 |
> |
idents = factory.getIdents(); |
| 209 |
> |
|
| 210 |
> |
o << "Avaliable type identifiers in this factory: " << std::endl; |
| 211 |
> |
for (i = idents.begin(); i != idents.end(); ++i) { |
| 212 |
> |
o << *i << std::endl; |
| 213 |
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} |
| 214 |
|
|
| 215 |
+ |
return o; |
| 216 |
+ |
} |
| 217 |
+ |
|
| 218 |
+ |
//static template class member |
| 219 |
+ |
template<class Object, typename IdentType,typename Creator> |
| 220 |
+ |
GenericFactory<Object,IdentType,Creator>* GenericFactory<Object,IdentType,Creator>::instance_ ; |
| 221 |
+ |
|
| 222 |
+ |
|
| 223 |
+ |
#define DECLARE_CREATOR(abstractObject, concreteObject) \ |
| 224 |
+ |
inline abstractObject* create##concreteObject(){\ |
| 225 |
+ |
return new concreteObject;\ |
| 226 |
+ |
} |
| 227 |
+ |
|
| 228 |
+ |
#define REGISTER_CREATOR(factory, ident, concreteObject) \ |
| 229 |
+ |
const bool registered##concreteObject = factory::getInstance()->registerCreator(ident, create##concreteObject); |
| 230 |
+ |
|
| 231 |
+ |
|
| 232 |
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}//namespace oopse |
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#endif //UTIL_GENERICFACTORY_HPP |
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|
