portapack-mayhem/firmware/application/signal.hpp
2016-11-26 16:50:44 -08:00

86 lines
2.1 KiB
C++

/*
* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
*
* This file is part of PortaPack.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef __SIGNAL_H__
#define __SIGNAL_H__
#include <cstdint>
#include <list>
#include <functional>
#include <memory>
#include "utility.hpp"
/* Tweaked and vastly simplified implementation of Simple::Signal, from
* https://testbit.eu/cpp11-signal-system-performance/
*
* Original license:
* CC0 Public Domain
* http://creativecommons.org/publicdomain/zero/1.0/
*/
using SignalToken = uint32_t;
template<class... Args>
struct Signal {
using Callback = std::function<void (Args...)>;
SignalToken operator+=(const Callback& callback) {
const SignalToken token = next_token++;
entries.emplace_back(std::make_unique<CallbackEntry>(callback, token));
return token;
}
bool operator-=(const SignalToken token) {
entries.remove_if([token](EntryType& entry) {
return entry.get()->token == token;
});
return true;
}
void emit(Args... args) {
for(auto& entry : entries) {
entry.get()->callback(args...);
};
}
private:
struct CallbackEntry {
const Callback callback;
const SignalToken token;
constexpr CallbackEntry(
const Callback& callback,
const SignalToken token
) : callback { callback },
token { token }
{
}
};
using EntryType = std::unique_ptr<CallbackEntry>;
std::list<EntryType> entries { };
SignalToken next_token = 1;
};
#endif/*__SIGNAL_H__*/