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uLib/src/Core/ObjectFactory.h

143 lines
4.0 KiB
C++

#ifndef U_CORE_OBJECTFACTORY_H
#define U_CORE_OBJECTFACTORY_H
#include "Core/Object.h"
#include <functional>
#include <map>
#include <string>
#include <type_traits>
#include <vector>
namespace uLib {
/**
* @brief Singleton factory for dynamic Object instantiation based on class
* name.
*/
class ObjectFactory {
public:
typedef std::function<Object *()> FactoryFunction;
/** @brief Get the singleton instance. */
static ObjectFactory &Instance();
/** @brief Register a factory function for a given class name. */
void Register(const std::string &className, FactoryFunction func);
/** @brief Create a new instance of the specified class. */
Object *Create(const std::string &className);
/** @brief Get the names of all registered classes. */
std::vector<std::string> GetRegisteredClasses() const;
private:
ObjectFactory() = default;
~ObjectFactory() = default;
// Prevent copy and assignment
ObjectFactory(const ObjectFactory &) = delete;
ObjectFactory &operator=(const ObjectFactory &) = delete;
std::map<std::string, FactoryFunction> m_factoryMap;
};
/**
* @brief Helper class to statically register a factory function.
*/
template <typename T> class ObjectRegistrar {
public:
ObjectRegistrar(const std::string &className) {
ObjectFactory::Instance().Register(className,
[]() -> Object * { return new T(); });
}
};
#define ULIB_REG_CONCAT_IMPL(a, b) a##b
#define ULIB_REG_CONCAT(a, b) ULIB_REG_CONCAT_IMPL(a, b)
/**
* @brief Macro to register a class to the factory.
* Put this in the .cpp file of the class.
*/
#define ULIB_REGISTER_OBJECT(className) \
static uLib::ObjectRegistrar<className> ULIB_REG_CONCAT( \
g_ObjectRegistrar_, __LINE__)(#className);
#define ULIB_REGISTER_OBJECT_NAME(className, registeredName) \
static uLib::ObjectRegistrar<className> ULIB_REG_CONCAT( \
g_ObjectRegistrar_, __LINE__)(registeredName);
/**
* @brief Utility wrapper that bridges factory registration and shared ownership.
*
* ObjectWrapper provides a high-level interface to handle objects that can be
* both registered in the ObjectFactory and managed through shared ownership
* using SmartPointer.
*
* One of its key roles is static registration: when instantiated with a
* class name string, it automatically registers a factory function for type T
* in the ObjectFactory singleton. This allows the factory to subsequently
* create instances of T dynamically by name.
*
* It supports multiple initialization paths, including factory-based
* construction and direct model wrapping.
*/
template <typename T> class ObjectWrapper {
public:
ObjectWrapper(const std::string &className) {
ObjectFactory::Instance().Register(className,
[]() -> Object * { return new T(); });
}
ObjectWrapper(T *model) : m_model(model) {}
ObjectWrapper(T &model) : m_model(model) {}
template <typename U = T,
typename = std::enable_if_t<std::is_default_constructible_v<U>>>
ObjectWrapper() : m_model(new T()) {}
ObjectWrapper(const ObjectWrapper &other) : m_model(other.m_model) {}
ObjectWrapper &operator=(const ObjectWrapper &other) {
m_model = other.m_model;
return *this;
}
ObjectWrapper(ObjectWrapper &&other) noexcept
: m_model(std::move(other.m_model)) {}
ObjectWrapper &operator=(ObjectWrapper &&other) noexcept {
m_model = std::move(other.m_model);
return *this;
}
~ObjectWrapper() = default;
T *operator->() const { return m_model.get(); }
T &operator*() const { return *m_model; }
T *GetWrapped() const { return m_model.get(); }
bool operator==(const ObjectWrapper &other) const {
return m_model == other.m_model;
}
bool operator!=(const ObjectWrapper &other) const {
return m_model != other.m_model;
}
explicit operator bool() const { return m_model != nullptr; }
protected:
SmartPointer<T> m_model;
};
} // namespace uLib
#endif // U_CORE_OBJECTFACTORY_H