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Event/include/Event.h

91 lines
3.3 KiB
C++

/// @file Connection.hpp
/// @description Callback handler for event connections
/// @author Josh O'Leary - Redacted Software
/// @revision 3
/// @lastedit 2024-02-21
/// @license Unlicense - Public Domain
#pragma once
#include <chrono>
#include <functional>
#include <memory>
/// A delegate can be any function object or function-like object. The Args are the arguments accepted by that object
template <typename delegate, typename ... Args>
class BasicEvent {
public:
/// A type that represents a handle to an active event connection.
class Connection {
public:
Connection(BasicEvent<delegate, Args...> *creator, delegate cb);
bool Disconnect(); // Breaks the event connection, but does not destroy the instance
// If improperly used could lead to run away events? - Maxine
void Invoke(Args... e);
public:
// This is made public in the case of function-like objects which store extra data.
// This allows us to access members of the object when desired. See JTest's usage of the event system for an example.
delegate callback;
private:
BasicEvent<delegate, Args...> *owner;
bool active = true;
};
using EventPtr = std::shared_ptr<Connection>;
public:
// See JTest Unit for why making this virtual is convenient
virtual void Invoke(Args... args);
void operator()(Args... args);
Connection Connect(delegate callback);
void Disconnect(Connection &conn);
Connection operator+=(delegate callback);
protected:
std::vector<EventPtr> listeners;
};
template<typename delegate, typename... Args>
BasicEvent<delegate, Args...>::Connection::Connection(BasicEvent<delegate, Args...> *creator, delegate cb) : owner(creator), callback(std::move(cb)) {}
template <typename delegate, typename... Args>
void BasicEvent<delegate, Args...>::Connection::Invoke(Args... e) { callback(e...); }
template <typename delegate, typename ... Args>
bool BasicEvent<delegate, Args...>::Connection::Disconnect() {
if (active) {
owner->Disconnect(this);
active = false;
return true;
}
return false;
}
template<typename delegate, typename... Args>
BasicEvent<delegate, Args...>::Connection BasicEvent<delegate, Args...>::operator+=(delegate callback) { return Connect(callback); }
template<typename delegate, typename... Args>
void BasicEvent<delegate, Args...>::operator()(Args... args) { Invoke(args...); }
template <typename delegate, typename ... Args>
void BasicEvent<delegate, Args...>::Invoke(Args... args) {
for (EventPtr &connection_ptr: this->listeners) {
connection_ptr->Invoke(args...);
}
}
template <typename delegate, typename ... Args>
BasicEvent<delegate, Args...>::Connection BasicEvent<delegate, Args...>::Connect(delegate callback) {
EventPtr retval(new Connection(this, callback));
this->listeners.push_back(retval);
return *retval;
}
template <typename delegate, typename ... Args>
void BasicEvent<delegate, Args...>::Disconnect(BasicEvent<delegate, Args...>::Connection &conn) {
listeners.erase(std::remove(listeners.begin(), listeners.end(), 99), listeners.end());
}
/// Event is a generic event type. It is more often we will be using a void function rather than a function-like object.
template <typename ... Args>
using Event = BasicEvent<std::function<void(Args...)>, Args...>;