cogito/esphome_dev/esphome/components/event_emitter/event_emitter.h

63 lines
1.9 KiB
C++

#pragma once
#include <unordered_map>
#include <vector>
#include <functional>
#include <limits>
#include "esphome/core/log.h"
namespace esphome {
namespace event_emitter {
using EventEmitterListenerID = uint32_t;
void raise_event_emitter_full_error();
// EventEmitter class that can emit events with a specific name (it is highly recommended to use an enum class for this)
// and a list of arguments. Supports multiple listeners for each event.
template<typename EvtType, typename... Args> class EventEmitter {
public:
EventEmitterListenerID on(EvtType event, std::function<void(Args...)> listener) {
EventEmitterListenerID listener_id = get_next_id_(event);
listeners_[event][listener_id] = listener;
return listener_id;
}
void off(EvtType event, EventEmitterListenerID id) {
if (listeners_.count(event) == 0)
return;
listeners_[event].erase(id);
}
protected:
void emit_(EvtType event, Args... args) {
if (listeners_.count(event) == 0)
return;
for (const auto &listener : listeners_[event]) {
listener.second(args...);
}
}
EventEmitterListenerID get_next_id_(EvtType event) {
// Check if the map is full
if (listeners_[event].size() == std::numeric_limits<EventEmitterListenerID>::max()) {
// Raise an error if the map is full
raise_event_emitter_full_error();
off(event, 0);
return 0;
}
// Get the next ID for the given event.
EventEmitterListenerID next_id = (current_id_ + 1) % std::numeric_limits<EventEmitterListenerID>::max();
while (listeners_[event].count(next_id) > 0) {
next_id = (next_id + 1) % std::numeric_limits<EventEmitterListenerID>::max();
}
current_id_ = next_id;
return current_id_;
}
private:
std::unordered_map<EvtType, std::unordered_map<EventEmitterListenerID, std::function<void(Args...)>>> listeners_;
EventEmitterListenerID current_id_ = 0;
};
} // namespace event_emitter
} // namespace esphome