listener.hh

Go to the documentation of this file.

// SPDX-FileCopyrightText: 2021-2025 The Ikarus Developers ikarus@ibb.uni-stuttgart.de
// SPDX-License-Identifier: LGPL-3.0-or-later
 
#pragma once
#include <algorithm>
#include <cassert>
#include <functional>
#include <iostream>
#include <memory>
#include <vector>
 
namespace Ikarus {
 
class Listener
{
public:
  using Token = std::shared_ptr<void>;
 
  template <typename Broadcaster>
  auto subscribe(Broadcaster& broadcaster,
                 std::function<void(typename Broadcaster::MessageType, const typename Broadcaster::State&)> callback) {
    auto token = broadcaster.registerListener(std::move(callback));
    tokens.push_back(token);
    return token;
  }
 
  void unSubscribeAll() {
    for (auto& token : tokens) {
      if (token) {
        token.reset();
      }
    }
    tokens.clear();
  }
 
  void unSubscribeLast() {
    if (!tokens.empty()) {
      tokens.back().reset();
      tokens.pop_back();
    }
  }
 
  void unSubscribe(const Token& token) {
    auto it = std::ranges::find(tokens, token);
    if (it != tokens.end()) {
      (*it).reset();
      tokens.erase(it);
    }
  }
 
private:
  std::vector<Token> tokens;
};
 
} // namespace Ikarus