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#pragma once
#include <cru/common/SelfResolvable.h>
#include <cstddef>
#include <functional>
#include <type_traits>
#include <utility>
#include <vector>
namespace cru {
template <typename TArgument, typename TResult>
class EventContext {
public:
EventContext() : argument_(), result_() {}
explicit EventContext(TArgument argument)
: argument_(std::move(argument)), result_() {}
EventContext(TArgument argument, TResult result)
: argument_(std::move(argument)), result_(std::move(result)) {}
TArgument& GetArgument() { return argument_; }
const TArgument& GetArgument() const { return argument_; }
TResult& GetResult() { return result_; }
const TResult& GetResult() const { return result_; }
void SetResult(TResult&& result) { result_ = std::forward<TResult>(result); }
bool GetStopHandling() const { return stop_handling_; }
void SetStopHandling(bool stop = true) { stop_handling_ = stop; }
private:
TArgument argument_;
TResult result_;
bool stop_handling_ = false;
};
template <typename TArgument, typename TResult>
class Event2;
template <typename T>
constexpr bool is_event2_v = false;
template <typename TArgument, typename TResult>
constexpr bool is_event2_v<Event2<TArgument, TResult>> = true;
template <typename TEvent2>
class EventHandlerToken {
static_assert(is_event2_v<TEvent2>, "TEvent2 must be Event2 class.");
public:
EventHandlerToken(ObjectResolver<TEvent2> event_resolver, int token_value);
ObjectResolver<TEvent2> GetEventResolver() const { return event_resolver_; }
int GetTokenValue() const { return token_value_; }
void RevokeHandler() const;
private:
ObjectResolver<TEvent2> event_resolver_;
int token_value_;
};
template <typename TArgument = std::nullptr_t,
typename TResult = std::nullptr_t>
class Event2 : public SelfResolvable<Event2<TArgument, TResult>> {
public:
using HandlerToken = EventHandlerToken<Event2>;
using Context = EventContext<TArgument, TResult>;
using Handler = std::function<void(Context&)>;
using SpyOnlyHandler = std::function<void()>;
template <typename TFunc>
static std::enable_if_t<std::invocable<TFunc>, Handler> WrapAsHandler(
TFunc&& handler) {
return Handler([h = std::forward<TFunc>(handler)](Context&) { h(); });
}
template <typename TFunc>
static std::enable_if_t<std::invocable<TFunc, Context&>, Handler>
WrapAsHandler(TFunc&& handler) {
return Handler(std::forward<TFunc>(handler));
}
private:
struct HandlerData {
int token_value_;
Handler handler_;
};
public:
Event2(const Event2&) = delete;
Event2(Event2&&) = delete;
Event2& operator=(const Event2&) = delete;
Event2& operator=(Event2&&) = delete;
~Event2() override = default;
public:
void RevokeHandler(int token_value);
void RevokeHandler(const HandlerToken& token) {
return RevokeHandler(token.GetTokenValue());
}
private:
int current_token_value_ = 1;
std::vector<HandlerData> handlers_;
};
template <typename TEvent2>
void EventHandlerToken<TEvent2>::RevokeHandler() const {
auto event = this->event_resolver_.Resolve();
if (event) {
event->RevokeHandler(this->token_value_);
}
}
} // namespace cru
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